Are we meat eaters or vegetarians? Part II
Meat eating made us human. The anthropological evidence strongly supports the idea that the addition of increasingly larger amounts of meat in the diet of our predecessors was essential in the evolution of the large human brain. Our large brains came at the metabolic expense of our guts, which shrank as our brains grew.
In April 1995 an article appeared in the journal Current Anthropology that was an intellectual tour de force and, in my view, an example of a perfect theoretical paper. “The Expensive-Tissue Hypothesis” (ETH) by Leslie Aiello and Peter Wheeler demonstrated by a brilliant thought experiment that our species didn’t evolve to eat meat but evolved because it ate meat.
The ETH is an example of the kind of scientific detective work that I love. In fact, this paper is one of my all time favorites. (An amazing bit of trivia about this paper is that it almost didn’t get published. I had the opportunity to talk with Leslie Aiello at a meeting a few months ago, and she told me that the journal was reluctant to publish the paper because they thought it too technical for their readers. I suspect they also found it too controversial. Now I’m sure they’re glad they published because I would imagine it is the most cited of all the papers ever published in Current Anthropology.) The authors methodically lay the scientific foundation for their experiment, then, like Sherlock Holmes, progress step by step, accumulating little pieces of data until they reach the ineluctable conclusion that meat eating made us human. I would like to walk us all through their thought processes as laid out in their brilliant paper.
Let’s start with the problem.
For years anthropologists have speculated about why humans developed such large brains so quickly – from softball size to what we have now in just a short 2 million years. Below is a graphic showing hominid/human brain growth over time.
A number of hypotheses have arisen to answer this question. Some say that humans developed large brains because they had to contend with problems involving group size, others posit that large brains came about as a consequence of developing complex foraging strategies, others yet say the development of a social or Machiavellian intelligence was the driving factor. And even others say that the complexities of learning to hunt expanded brain size.
Any or all of these hypotheses may be valid, but the problem isn’t really as much a matter of why as it is a matter of how. Other primates deal with groups and have complex foraging strategies; and many deal with social problems within their groups, and some even hunt. Yet they still have small brains. (Granted, their brains are larger for their size than those of other mammals, but primates sport small brains as compared to humans.) How did the human brain grow?
This isn’t an easy question to answer because of the thermogenics involved. Brains consume a large amount of fuel and, consequently, throw off an enormous amount of heat for their size. The metabolic rate of brain tissue is nine times that of the average of the metabolic rate of the rest of the body.
So what? you may say. So we’ve got a big, hot-running, energy-burning brain. What difference does that make? It’s reflected in our overall metabolic rate, right? Well, sort of, and therein lies the crux of the problem. As we will see below, our total metabolic rate – even with our huge brains – is the same as that of any other animal our size. Or to say it another way, animals our size with much smaller brains have the same metabolic rate that we do with our huge brains. This fact was the starting point for the authors of the ETH. So let’s start there as well.
In keeping with a great scientific tradition, Aiello and Wheeler were able to see what they saw because they stood on the shoulders of giants who came before them. In their case the giant was Max Kleiber, an animal physiologist working at the University of California at Davis, who published a groundbreaking paper in 1947 and a scholarly text titled The Fire of Life in 1961. Kleiber’s work involved the meticulous measurement of the metabolic rates of numerous animals, including humans. As he plotted the various metabolic rates, he discovered an extremely strong correlation between the mass of an animal and its metabolic rate. Kleiber found that this relationship held constant across numerous species. His October 1947 paper in Physiological Reviews simply titled “Body Size and Metabolic Rate” was a classic. By using the equations Kleiber worked out, the metabolic rate of virtually any animal could be determined simply by knowing the animal’s body size. Or, as Kleiber put it in the paper:
Does a horse produce more heat per day than a rat or do some rats produce more heat than do some horses? Almost anybody who understands what is meant by “heat production per day” will not hesitate to give the correct answer and will even be convinced that the daily rate of heat production of men or sheep is greater than that of rats, but smaller than that of horses. Thus most people (among those who understand the question) are convinced that in general the bigger homeotherms produce more heat per day than the smaller homeotherms, that, in other words, the metabolic rate of homeotherms is positively correlated to body size.
The answer to the next question: “does a horse produce more heat per day per kilogram of body weight than a rat?” requires some biological training. Most biologists, however, will not hesitate to answer that the rate of heat production per unit body weight of the big animal is less than that of the small animal.
The positive correlation between metabolic rate and body size, and the negative correlation between metabolic rate per unit weight and body size, establish two limits between which we expect to find the rate of heat production [basal metabolic rate] of a horse if we know the rate of heat production of a rat. We expect the metabolic rate of the horse to be somewhere between that of the rat, and that of the rat times the the ratio of horse weight to rat weight, provided of course that we do not regard these two correlations as simply accidental.
If we are firmly convinced that the metabolic rate of horses, and other homeotherms of similar size, is never outside these two limits, then we admit to recognize a natural law between body size and metabolic rate.
This natural law, carefully calculated by Kleiber, is now known as Kleiber’s law. Below is Kleiber’s law graphed out by him as it appeared in his seminal paper. And this is exactly as it appeared in the journal, but with the addition here of colors for better legibility. Since their was no Excel nor graphics software in Kleiber’s time, the graph was hand drawn and appeared in the pages of Physiological Reviews as such. How times have changed.
As you look along the line running from lower left to upper right, you can find rats and horses and a host of other mammals including humans. Over the years, mammals that Kleiber didn’t have the opportunity to work on have been measured, and they all fit nicely along Kleiber’s line, following Kleiber’s law. Because of this tight correlation, Kleiber’s equations can be used to precisely estimate the metabolic rate of any animal just by knowing its size.
Aiello and Wheeler used Kleiber’s law as the jumping off point for their grand thought experiment.
Since all animals measured have conformed to Kleiber’s law, Aiello and Wheeler postulated that animals now extinct – including our human and pre-human predecessors – would have fallen along the same line. Using skeletal remains paleontologists have been able to calculate body sizes of extinct animals along with pre-Homo and early-Homo species. Then using Kleiber’s law, it is possible to closely estimate the metabolic rates of these creatures. And here’s where it gets interesting.
According to Kleiber’s law, an australopithecine weighing 80 pounds would have the same metabolic rate as a human weighing 80 pounds despite the disparity in brain size between the two. The much larger brain of the human would have 4-5 times the metabolic rate of the brain of the australopithecine, yet would have the same overall metabolic rate. What gives?
That’s precisely what the authors of “The Expensive-Tissue Hypothesis” wondered.
Because the human brain costs so much more in energetic terms than the equivalent average mammalian brain, one might expect the human BMR [basal metabolic rate] to be correspondingly elevated. However, there is no significant correlation between relative basal metabolic rate and relative brain size in humans and other encephalized animals.
Where does the energy come from to fuel the encephalized brain?
The authors postulated a solution.
One possible answer to the cost question is that the increased energetic demands of a larger brain are compensated for by a reduction in the mass-specific metabolic rates of other tissues.
In other words, if one organ – the brain, for example – is chewing up a lot of energy and contributing a disproportionate amount of the basal metabolic rate for the animal as a whole, then maybe another organ or group of organs are consuming less energy to compensate. The heart, the kidneys, the liver, the skeletal muscles, the GI tract – all consume energy and contribute to metabolic rate. Maybe one of these organs became smaller as the brain became larger over time.
We can hone our analysis a little finer if we begin to look at an energy-balance equation, but an energy-balance equation of a different kind. I have written a number of times in this blog about the energy-balance equation that applies to weight loss: change in weight equals energy in minus energy out. That is not the equation we’ll be talking about here. The other energy-balance equation says that the total metabolic rate is the sum of all the metabolic rates of the various organs and tissues in the body. If you add the metabolic rates of the kidneys, the heart, the brain, the muscles, the digestive tract and so on together, you will get the total metabolic rate of the body, which makes sense because it is the sum of the parts.
Total BMR = brain BMR + heart BMR + kidney BMR + GI tract BMR + liver BMR + the remainder of the body’s tissues.
The authors of the ETH set out to look at the metabolic rates of the various organs. By a diligent search of the literature, they found that along with the brain, the the heart, the kidneys, the liver and the gastro-intestinal tract account for the vast majority of the total BMR. They dubbed these organs as ‘expensive tissues’ because they consume a large amount of energy as compared to their size. (Surprisingly, muscle mass doesn’t contribute all that much to the total metabolic rate (skin and bone contribute even less), which gives the lie to that old notion — that I, myself, have fallen prey to — that replacing fat with muscle increases metabolism significantly.)
Aiello and Wheeler reasoned that if the total metabolic rate stayed the same while the energy-expensive brain grew over time some other expensive tissue had to get smaller. There could be no other solution.
But which of the expensive tissues got smaller?
Aiello and Wheeler examined the data on the metabolic rates and sizes of the various expensive tissues and learned that for a 65 kg primate, the heart, the kidneys, and the liver were approximately the same size as those of a 65 kg (143 lb) human. The greater metabolic rate of the large human brain was compensated for by a GI tract significantly decreased in size. It turns out that the GI tract of a 65 kg human is just a little over half the size of the GI tract of a similar sized primate.
The combined mass of the metabolically expensive tissues for the reference adult human is remarkably close to that expected for the average 65-kg primate, but the contributions of individual organs to this total are very different from the expected ones. Although the human heart and kidneys are both close to the size expected for a 65-kg primate, the mass of the splanchnic organs (the abdominal organs) is approximately 900 g less that expected. Almost all of this shortfall is due to a reduction in the gastro-intestinal tract, the total mass of which is only 60% of that expected for a similar-sized primate. Therefore, the increase in mass of the human brain appears to be balanced by a almost identical reduction in size of the gastro-intestinal tract.
Below is a graphic from the ETH showing the sizes of the different organs as based on predictions from a 65-kg primate and the observed size in humans.
So we know that as humans evolved larger brains they simultaneously co-evolved smaller guts in order to maintain a set BMR. And this is where the story gets interesting. Why? Because
the logical conclusion is that no matter what is selecting for brain-size increase, one would expect a corresponding selection for reduction in the relative size of the gut.
Some researchers believe that increasingly complex activities drove the brain to enlarge. As the authors of the ETH summarized it:
The relationship between relative brain size and diet is often mentioned in the literature on primate encephalization and is generally explained in terms of the different degrees of intelligence needed to exploit various food resources. For example, [some] have argued that a relatively large brain and neocortical size correlates with omnivorous feeding in primates , which requires relatively complicated strategies for extracting high-quality foodstuffs. Alternatively, [others] have suggested that frugivores have relatively large brain sizes because they have relatively larger home ranges than folivores, necessitating a more sophisticated mental map for location and exploitation of the food resources.
But it doesn’t matter whether our brains got big because our predecessors were socialized, developed complex foraging strategies, lived in and had to deal with groups or were skilled hunters, in order to obey Kleiber’s law, something had to force our guts to get smaller at the same time. What could that be?
According to Aiello and Wheeler, it is increased diet quality that allowed the gut to get smaller while still absorbing the necessary nutrients to fuel the metabolism. As they put it
The results presented here [in the ETH] suggest that the relationship between relative brain size and diet is primarily a relationship between relative brain size and relative gut size, the latter being determined by dietary quality. This would imply that a high-quality diet is necessary for this encephalization, no matter what may be selecting for that encephalization. A high-quality diet relaxes the metabolic constraints on encephalization by permitting a relatively smaller gut, thereby reducing the considerable metabolic cost of this tissue.
What the authors are saying is that it doesn’t matter how much more brain power was required, the brain couldn’t enlarge without something else giving. What obviously gave was the size of the GI tract, and the only way a smaller GI tract could provide the fuel for the body was to have a higher-quality diet. How did the our most ancient relatives the early hominids increase the quality of their diets?
A considerable problem for the early hominids would have been to provide themselves, as large-bodied species, with sufficient quantities of high-quality food to permit the necessary reduction of the gut. The obvious solution would have been to include increasingly large amounts of animal-derived food in the diet.
Increasing the amount of easily-digested food of animal origin allowed us to shrink our guts while expanding our brains. Had we remained on a diet high in vegetation, we would no doubt not have been able to expand our brains irrespective of how much more thinking those brains would have needed to do. It just wouldn’t have been possible to do so without violating Kleiber’s law.
Take the gorilla, for example, almost pure vegetarians that spend their entire ‘working’ day foraging and eating, which they have to do to get enough calories to maintain their enormous bulk. They have large guts and pay for it by having small brains. Even smaller than that of our most primitive ancestors, the australophthecines.
Gorilla has one of the lowest levels of encephalization of any haplorhine primate, and the much higher level of encephalization of all the australopithecines suggests a diet of significantly higher quality than that of this genus.
Which makes sense when you consider that carbon 13 isotope analysis has shown that Australopithecus africanus (the species that came right after Lucy) consumed meat. As you go up the lineage from Australopithecus and through Homo, you find that more and more meat was consumed the higher up the tree you go.
It’s easy to see that, as compared to humans, chimps and gorillas have large, protuberant bellies, which supports the fact that they have larger GI tracts, but what about our ancient ancestors. All we have to go on are skeletal remains, which show nicely that their heads (and brains) were much smaller than ours, but what about their guts? How do we really know their guts were larger? According to Kleiber, they would have to be, but how to we really know they were?
The large gut of the living pongids gives their bodies a somewhat pot-bellied appearance, lacking a discernible waist. This is because the rounded profile of the abdomen is continuous with that of the lower portion of the rib cage, which is shaped like an inverted funnel, and also because the lumbar region is relatively short (three to four lumber vertebrae).
The drawing below from the ETH shows the inverted-funnel shape of the ribcage of the chimpanzee on the left. You can mentally draw the lines downward from these ribs and envision the pot-bellied look of the abdomen that these primates evidence. Looking at the image on the right, you can see that Australopithecus afarensis (Lucy’s species) has the same inverted-funnel shaped rib cage, indicating a large belly and a low-quality diet.
The drawing in the middle is of a modern human. If you extrapolate the lines down from the human rib cage, you can see that they lead to a more narrow waist. Makes you think more of a lean, rangy wolf or other slim-waisted carnivore, whereas the other two don’t.
The authors conclude:
If an encephalized animal does not have a correspondingly elevated BMR [which according to Kleiber, it can’t], its energy budget must be balanced in some other way. The expensive-tissue hypothesis suggested here is that this balance can be achieved by a reduction in size of one of the other metabolically expensive organs in the body (liver, kidney, heart of gut). We argue that this can best be done by the adoption of a high-quality diet, which permits a relatively small gut and liberates a significant component of BMR for the encephalized brain. No matter what was selecting for encephalization, a relatively large brain could not be achieved without a correspondingly [sic] increase in dietary quality unless the metabolic rate was correspondingly increased.
At a more general level, this exercise has demonstrated other important points. First, diet can be inferred from aspects of anatomy other than teeth and jaws. For example, an indication of the relative size of the gastro-intestinal tract and consequently the digestibility of the food stuffs being consumed is provided by the morphology of the rib cage and pelvis. Second, any dietary inference for the hominids must be consistent with all lines of evidence. Third, the evolution of any organ of the body cannot be profitably studied in isolation. Other approaches to understand the costs of encephalization have generally failed because they have tended to look at the brain in isolation from other tissues. The expensive-tissue hypothesis profitably emphasizes the essential interrelationship between the brain, BMR, and other metabolically expensive body organs.
I hope you are now armed with enough knowledge to be able to see through these articles and/or charts that are all too common showing how the GI tract of humans is closer to that of a gorilla than it is to that of a cat or some other carnivore. It seems to me that Aiello and Wheeler have pretty thoroughly demolished the notion that humans are actually designed by the forces of natural selection to be vegetarians. Based on the data and the argument they present, it is actually the opposite: we evolved to be meat eaters.
It was our gradual drift toward the much higher quality diet provided by food from animal sources that allowed us to develop the large brains we have. It was hunting and meat eating that reduced our GI tracts and freed up our brains to grow. As I wrote at the start of this post, the evidence indicates that we didn’t evolve to eat meat – we evolved because we ate meat.
Lierre Keith had it right in The Vegetarian Myth:
The wild herds of aurochs and horses invented us out of their bodies, their nutrient-dense tissues gestating the human brain.
If we evolved because we ate meat, why would we want to stop now?
Note: I found the full text of this article available on Scribd. If it gets taken down, let me know, and I’ll put it up here. I’m just trying to save space on my server.
Painting at top: Monkey Before Skeleton by Gabriel Cornelius von Max
Good stuff. I’m curious to see how Tim’s avid vegan/vegetarian readers respond though (if any take the time to read it).
Scientific proof that vegetarians are idiots. I love it!
Probably proof that vegetarians have never read this paper.
Maybe that joke was in poor taste. I just wanted to say that this is an amazing blog post, worthy of award (if such things exist). This is just the kind of writing we all need – someone to take good research that may be over our heads, and explain it to us piece by piece. Thank you so much!
Let’s try to get this on Digg
I would be clueless as to how to get something on Digg. What do I have to do?
Woohoo, it’s here!
Brilliant! Thanks for explaining the details of this paper. Just downloaded it.
Btw., here’s a video answering the question of who’s the biggest carnivore.
http://vids.myspace.com/index.cfm?fuseaction=vids.individual&videoid=22050793
Nice video.
I guess this means that instead of eating we can inject already broken down nutrients and get even bigger brains. Fascinating.
This was quite convincing. Eating meat evolved our brains. But now that we have big brains and small GIs, what happens now if we substitute meat for vegetables? Will my brain get too little energy if I eat lots of vegetables and not so much meat? Will this make me less smart? Sodas might make up for (hypothetically) decreased consumption of meat?
A little grammatical error in “As you goes”. Really great article. You have material for writing hundreds of books. Why have you written so few?
Thanks for the heads up on the error – I’ve fixed it.
Writing books is a pain. Plus no editor would buy a book filled with a lot of the stuff I post in this blog because he/she wouldn’t think it would sell because it would be over the head of the average reader. By and larger, editors (the ones who buy the books) don’t have a very high opinion of the reading public.
Superb!
Much appreciated.
Hi Dr Mike.
Thank you for writing so well in bringing another interesting scientific narrative to our attention. I’ve downloaded the paper from ScribD so I can read it more deeply myself.
I also like the picture; I am particularly intrigued by the pen, paper and the steady, contemplative, even intelligent gaze of the monkey. Gabriel van Max was an interesting character and seemingly love his monkeys.
May I also say that you give a great visual impact to your posts by using the coloured illustration, whether painting or photograph. Clearly you have design and artistic skills as well as superb writing ability!
BTW shouldn’t “brilliant though experiment” be “thought” in second para above?
On supine SAD and VAT I found the following paper
http://www.andrologyjournal.org/cgi/rapidpdf/jandrol.108.005215v1.pdf
which includes using coronal abdominal diameter with SAD to estimate viscerality.
I just love the stick figure representations showing where measurements were taken!
I’m now off to have the 1st coco milk shake of my day, on 10th day of liver detox.
Y’all take care, now.
It does say ‘brilliant thought experiment’ now. Thanks for the heads up.
I never thought about it vis a vis the pictures I put up on this blog, but I suppose I do have some artistic skills.
I think you sent the wrong paper. The one above is about metabolic syndrome and erectile dysfunction.
Dear Dr Eades
Fat, Protein and Nephritis
Many thanks for this and the previous blog on meat eating…excellent stuff.
You name checked Stefansson on Sept 17. He, and some other polar explorers of the late 19th and early 20th century, noted how they thrived on meat only diet. Nansen, for example, when his supplies ran out, had to exist off a meat only diet based on what he could hunt and kill.
I should like to quote Donald B Macmillan writing in 1920, recalling his time with Peary on their 1908/09 attempt on the Noth Pole:
The men…”in quest of musk-oxen, caribou, and Arctic hare: for Peary, who never had a single case of scurvy on any of his expeditions, fully appreciated the value of fresh meat as an antiscorbutic. Fresh vegetables, acids, and fruits are not necessary. This fact we have known for at least a half century, having acquired it from the experience of the American whaling captains. Scurvy stricken patients were always dispatched by them immediately to the igloos of the Eskimos, there to be restored to health by consuming raw frozen meat.”
However, during Stefansson’s ill-fated Karluk expedition in 1913-1914, the men, living on mainly pemmican, were stricken down with a mystery illness. It turned out to be nephritis. To quote from Jennifer Niven in the “Ice Master”:
“The mystery illness was nephritis caused by too much protein and fat in the diet. The very pemmican that had been keeping them alive had also been killing them. As long as they had had biscuits, they were fine, but without carbohydrates in the biscuits to balance their intake of protein, they were doomed. The fresh meat had been much better for them than the pemmican, but there had not been enough of it. It was the pure pemmican diet that had killed Mamen and Malloch, and it was the pemmican that had made the rest of them so desperately ill. Before the expedition began, Stefansson had damned the purity tests and purchased the pemmican without having it analyzed”.
The quote does stress the difference between fresh meat and pemmican, but could you perhaps provide some further details on nephritis and excess protein and fat and her comment on carbohydrates?
She is incorrect. As far as I know, there is nothing in biscuits that will ‘balance’ protein. Too much protein alone can cause problems (Stefansson referred to the problem as rabbit fever), but if protein is consumed with either fat or carbohydrate (or both), the problem goes away. Pemmican is made of jerky and fat, and, according to Stefansson, many people have survived for long periods on jerky alone, so I doubt the deaths were caused by the pemmican unless the pemmican were somehow tainted.
Terrific article. You know, Doc, I’d have to sit down and think about it for awhile in order to come up with a longer list, but from all my reading, including now this, it sure seems like we are amassing a number of “discoveries” that completely flip what we previously thought was correct cause and effect. There’s this meat/brain one, and there’s “people don’t get fat because they’re lazy, they’re lazy because they’re fat”. There’s “the taking on of challenging academic subjects doesn’t make you smart, it’s because you are already smart that you are drawn to challenging academics”. And being depressed and anxious don’t cause you to have debilitating thoughts and actions, it’s the “chosen” types of thoughts that cause you to be anxious/depressed.
Etc.
Amazing. What’s next?
Who knows? Glad you enjoyed the post.
Thanks for this wonderful summery. But, woe and double woe, the 6 Week Cure still hasn’t made it here yet! Bloody Amazon only offered one option for shipping to Australia and it’s obvious that the runner with the forked stick died on the way.
But I can offer you something of beauty in return! Mr Postman left me the latest Brahms recording in the Sir John Eliot Gardiner series and it contains some amazing choral gems some of which Sir John has also posted on the Interwebby Thingy (as my son calls it):
Brahms – Ich schwing mein Horn ins Jammertal
http://www.solideogloria.co.uk/realaudio/704_1.ram
Brahms – Einförmig ist der Liebe Gram (magic!!! Based on Schubert’s Organ Grinder)
http://www.solideogloria.co.uk/realaudio/704_4.ram
Brahms – Nänie (complete! requires a larger orchestra than the symphonies and a larger choir than the above!)
http://www.solideogloria.co.uk/realaudio/704_10.ram
Also on the CD but not on the web, is The Song of Fate (almost as lovely as the Song of Destiny).
And, BTW you also get a superb performance of the the 3rd Symphony, but I bet you’ve heard that work before!
Michael
Thanks for the Brahms. It’s playing as I write these words.
PS Sorry, wrong link for SAD and VAT: should be
http://www.nature.com/oby/journal/v14/n7/full/oby2006135a.html
Thanks. I read this paper when writing that section of the book, but somehow it never made it into the bibliography. I even contemplated using one of the figures.
Love it. With due respect, could some of the increase in diet quality come from animal tissue, yet another portion come from our mastery of fire and consuming cooked vegetation?
In the paper Aiello and Wheeler describe two large jumps in brain size. The first they attribute for sure to the increase in meat eating because it was prior to the discovery of fire; the second they speculate may have come about because of cooking. But, remember, cooked meat is better digested than raw meat, so even cooking just meat will provide a higher quality diet.
Just one more piece of evidence that supports how well I’ve been feeling on my 5 months of pure carnivory.
Awesome Doc! Great theory, and one that certainly makes one wonder if the reason some of our current vegetarian friends don’t “get” the lower carb notion, might be because their brains are shrinking due to their diet!!!
A bit off topic, but if you carry the “evolve because we ate meat theory” over the next few million years, you can envision a being that looks something very eeriely looking like the typical drawing of an alien!!! :0
Thanks for a well written blog!
-Meat only eating for the last year!!!-
Excellent post, as usual. Thank you.
Why doesn’t the ETH logic apply to other carnivores? Lions eat meat but don’t seem very smart. How do they maintain parity with Kleiber’s law?
Lions and other carnivores obviously didn’t have the selective pressures to develop larger brains that humans did.
Excellent!
It’s amazing that our primate relatives are used as evidence for our alleged vegetarian instincts whilst hominid evolution is simply ignored. The evidence for human meat eating is so overwhelming that it could be something only as contemptible as wishful thinking that compels a person to dismiss it.
Vegetarians are free to eat like chimpanzees if they want – I’ll eat more like a neanderthal myself – but it is annoying that they falsify and mispresent evidence to justify their lifestyle choice. Why do they think they need to?
On this point Michael (wishful thinking), have you ever read Steven Goldberg’s books? I think they’d be up your street.
I haven’t read Goldberg’s books, but I just looked them up. You’re right. They sound right up my alley. I’ll have to order a couple.
Fascinating! What is the connection between the nutritional quality of meat and a smaller digestive tract?
Meat contains many more nutrients – including calories – per unit mass than plan foods. Since meat is vastly more nutritionally dense than vegetation, it requires a much smaller GI tract to extract the nutrients from meat.
Wow, that’s amazing!
It also reminds me of the opening scene of 2001: A Space Odyssey. The monolith teaches the ancient apes to make tools–everyone remembers that part–but the first thing they do with the tools is use them to kill a large animal and devour its meat. I wonder why Kubrick & Clarke filmed it that way.
Absolutely fascinating post. Thank you!
I’d be curious to see within-species data regarding relative sizes (and thus energy expenditure) of brain/gut. It may have been advantageous to allow for developmental differences in brain-gut ratio depending on diet…
One of the best blog posts I’ve ever read. Gripping, well-written and ruthlessly logical. Amazing. Keep it up.
Thanks. But I didn’t so much as write it as I simply explained a brilliant paper.
Dear Dr. Eades:
Evolution is a faith based theory. If you were to evaluate your conclusions from information that is science based — observable and repeatable — information, would you come to the same conclusions? And I do not mean only in relation to this article but in relation to all that you conclude about how to eat. It would give validity to your conclusions for those of us whose faith is based on the literal Word of God.
It might be interesting to note that the Bible teaches that man was created on the 6th day in God’s image, man began as a vegetarian, not eating meat until after the flood.
Just thought I would suggest this without any expectations of your consideration.
I do enjoy some of your newsletters. Thank you for all the work you do and share.
Thanks for writing.
Thank you for this amazing post. I’ve forwarded it to all my carnivorous, LC friends. I had heard of Kleiber’s Law from a book called ‘Simplexity’ by Jeffrey Kluger. Have you read that? I loved it. Thanks a trillion for all your work.
Haven’t read ‘Simplexity,’ but it looks like my kind of book. Thanks for the recommendation.
If it was meat consumption alone that lead to our increased brain size, then why didn’t other carnivores, especially cats, also develop large brains? Lierre Keith posits in “The Vegetarian Myth” that it is man’s unique ability to crush our prey’s skull and get access to the fatty brain (mostly saturated fat at that) which ultimately allowed our human ancestors to develop their own large brains. BTW, I love this book! Thanks for recommending it.
The big cats developed through a different line than we did. They may not have had the selection pressures we did – given our relatively small bodies and relative lack of strength and speed – to grow a large brain.
Perhaps you can shed some light on the issue of dairy consumption, in light of these amazing discoveries. Specifically, i’m interested in where the disconnect is between the approach of the Paleolithic diet regime and the approach of the WAPF. The former, of course, restricts dairy entirely (in my understanding), arguing that we’d have never consumed dairy in our prehistoric state, whereas the latter vehemently champions the incorporation of raw dairy only into the diet, claiming that whole raw milk is a “perfect food”. If memory serves, some nomadic herding groups have consumed milk as a staple and many have consumed various raw, fermented dairy foods (Dr. Eades, I believe you referenced Mongol usage of yogurt at one time…), but none in the paleolithic era.
It’s my understanding that for most low-carb dieters, this issue is moot, as even whole milk is a problem because of the quantity of carbs. I’ve read some conflicting ideas on the carb count for yogurt and kefir, but it appears these forms of milk may have a diminished carb count and thus would be acceptable (and probably more digestible). Is this true? If lactose is the indigestible component of milk, the lactose-consuming bacteria present in fermenting milk should solve the indigestibility issue. The question for me, then, is DOES this solve the sugar issue, as some (Dr. Goldberg, etc) claim?
It does not totally solve the sugar issue. Lactose (milk sugar) is a disaccharide – a sugar composed of two sugar molecules – made of galactose and glucose. Both galactose and glucose are sugars that are easily digested, but not when hooked together as lactose. All of us can break down lactose to its two simple sugars when we are young, but many lose that ability with age. If we can’t break down lactose to galactose and glucose, then we can’t absorb it. If we can’t absorb it, it continues down the GI tract and provides food for bacteria, which produce gas, bloating and diarrhea as a consequence. Some of the lactose is converted to acid in the yogurt-making process, leaving less for the GI tract to deal with. Yogurt contains less sugar than the amount of milk used to make it, but all the sugar is not gone. You still have to account for some.
“I haven’t read Goldberg’s books, but I just looked them up. You’re right. They sound right up my alley. I’ll have to order a couple.”
Great. You’ll like them – I promise.
Thanks for the blog. I learn a lot.
Regarding what Stefan said about the opening of 2001: A Space Odessy. I wonder if tools weren’t developed to kill other animals so much as to kill each other, first.
While I am a firm believer in that we evolved eating meat, here is the McDougall version on why we evolved as starch eaters: http://www.drmcdougall.com/misc/2007nl/oct/fav5.htm , http://www.nealhendrickson.com/mcdougall/030700pumeatinthehumandiet.htm
“Proponents of meat-based diets preach that the introduction of meat into the human diet was responsible for the evolutionary development of the human brain. One of this study’s principle authors said this theory is improbable. Nathaniel Dominy pointed out, “Even when you look at modern human hunter-gatherers, meat is a relatively small fraction of their diet. They cooperate with language, use nets; they have poisoned arrows, even, and still it’s not that easy to hunt meat. To think that, two to four million years ago, a small-brained, awkwardly bipedal animal could efficiently acquire meat, even by scavenging, just doesn’t make a whole lot of sense.”
The paragraph about the modern human hunter-gatherers is simply not true. Here is a link to a paper in the American Journal of Clinical Nutrition, the world’s most prestigious nutritional scientific journal showing that modern hunter-gatherers get on average 65 percent of their calories from food of animal origin.
Hi Mike – thanks for the heads-up to your I’ve Been Tagged post : quite a history.
Reminds me that April last I came across “Discover Your Strengths” by Marcus Birmingham from the Gallup Organization. It’s an approach now used in Human Resources(HR) management to analyse what are termed Strengths – really Talents or Bents – rather than physiological or intellectual skills. It may also be used in Career Advice. Have you come across it?
Having bought & read the book I found it had a code which I could use on the StrengthsFinder site to take a questionnaire. I was then given my 5 Signature Themes. These themes explained many of the successes and failures in my career as well as many of my approaches to Life, the Universe & Everything. I was impressed. (They invited me to pay USD 500 for a telephone consult to explore my next 10 themes, but I declined!)
My take is, if you have not come across it, you would find it interesting; after all you recommended Glasser’s Choice Theory!
Google “strengthsfinder” if you want to follow it up.
BTW what did you think of Jonah Lehrer’s hypothesis on placebo effect in chapter five of The Decisive Moment? I liked it.
Any chance of a literary post – when you have a leisure moment?
Desmondo
I’ll take a look at the StrengthFinders site. I did enjoy Lehrer’s book from beginning to end.
Whenever I get a leisure moment, I’ll see if I can crank out a literary post.
@ Dr. Mike
I already submited this story to Digg. You can see your Digg page here:
http://digg.com/health/Are_We_Meat_Eaters_or_Vegetarians
Unfortunately, Diggers seem to side with the vegetarians on this issue, according to the responses in other vegetarian stories. I bet they all use Apple computers too!
I use an Apple (Mac), and I certainly no vegetarian.
I just realized that I used to have a Digg button on my blog, but it vanished during the redo.
The paper also explains a fallacy often put forward by Natural Hygienists, that carnivores have short GI tracts because “they must get rid of the meat quickly before it putrefies”. No, it’s because GI tracts are metabolically expensive and you don’t evolve a longer GI tract than you have to. This sort of scientific rigor is what attracts me to the paleo/primal diet theories, they just make SENSE!
Yes, that nonsense about meat putrefying sets my teeth on edge every time I see it.
Fantastic post; glad I was able to d/l the journal article from Scrib’d to digest further. Yet another tool to counter the veggie folks’ assertions that we all started out as plant eaters (well, we did, but that was long ago, when we resembled our primate cousins).
I had seen comparisons of modern herbivores to human GI tracts (i.e., sheep vs. human in one of your books), but had never thought to look at hominid evolution. It is interesting that our emphasis on carbohydrates has led to many of us adopting a faux-gorilla profile.
Yes, indeed. I was going to add that to the post, but decided not to because (a the post was going on forever as it was, and (b I didn’t want to insert my opinion into the piece.
Long time reader, first time commenter. Great article and it makes a lot of sense.
I am apparently the third to pick out carnivorous cats as making this theory questionable. Even though you answered the question earlier regarding cats I am still a bit unsatisfied. Cats may not have had the same selective pressures, but they do have small(er) GI tracts from what I hear. If that is the case then either Kleiber’s law is violated and they have a lower metabolic rate OR there is some other metabolically expensive tissue that makes up for it (instead of brain matter). Is it their musculature that is larger in proportion to their bodies that grew as a result of their selection pressure? I would love to see the chart of a big cat’s actual and expected as in the organ weight chart above. Muscle is my guess but I am not sure since you mentioned it isn’t much of a contributor. I would be curious as to your answer.
Great stuff and keep up the good work,
Jeff(meat and paleoish low-carb eater)
I don’t have the data on the big cats. The Expensive-Tissue Hypothesis was written to address the rapid increase in human brain size. We are a totally different genus and species from lions and tigers, so what applies to us doesn’t necessarily apply to them. They are on the Kleiber line, but I don’t know what makes up the difference anatomically between their small GI tracts and brain size. Obviously something does – I just don’t know what because I’ve never studied it. Lions do have a considerably larger muscle mass on a per body unit basis than humans, so maybe some of it is there. Since they are in a different genus, maybe their hearts and/or kidneys are larger as well. Aiello and Wheeler compared us to primates, since that is the line from which we descended.
I would like to comment on the post of Charlie Gayle concerning possible bad effects from eating pemmican. About the time when these men became ill from eating pemmican the nutritionists became increasingly influential. The nutritionists thought that the addition of carbohydrates would make pemmican more nutritious. The pemmican in question may not have been the traditional pemmican of earlier times. Barry Groves in his book “Trick and Treat” believes that the nutritionists might be primarily responsible for the deaths of Captain Scott and his South Polar expedition team in 1912. They were carrying food with a low energy density. Pemmican is food with almost the highest energy density possible so that a very large amount of calories can be carried without any replenishment.
You should add a “share on facebook” link to your blog entries: http://www.facebook.com/share_partners.php
I don’t even have a Facebook account. I was going to do it, but Tim Ferriss told me it was a bigger PITA than it was worth. All I need is some other way for people to send me emails and messages that I would feel obliged to answer.
Thanks for the great post!
One thing that never seems to be mentioned in the carnivore vs herbivore discussion is that humans probably ate of lot of bugs and worms–some still do. Good protein but not difficult to hunt.
True. That was addressed in the AJCN paper I linked to in an earlier comment.
Great post! Echoing the same praises as other commenters. As a nonscientist, I probably would not have understood this without a clear explanation like this. Many thanks, Dr. Mike.
Glad you enjoyed it.
Back in my anthropology days at school we were lectured about the importance of meat to human evolution, but I don’t recall that our professor talked so much about the GI tract as the quality of the diet, and the chewability. If I remember correctly (not guaranteed!), as the diet grew finer and contained less roughage and coarse plant fibers, there was a corresponding decrease in tooth and jaw size, but the attachment sites on the skull for the jaw musculature also decreased, which allowed the intracranial capacity to increase.
This could be a potential explanation for why other carnivores such as the large cats haven’t evolved human-like large brains – they need their massive jaw musculature for hunting and breaking apart carcasses.
Thoughts?
Interesting idea, but, as Aiello and Wheeler warned in the ECT, you’ve got to be careful deriving theories from specific anatomical points without looking at the total picture. But, could be the difference between us and the big cats.
Hi Dr. Eades,
Very nice. But there’s the issue of cooked starchy tubers– those are also a high-quality food in terms of calories per unit fiber and ease of digestibility. The brain is a glucose hungry organ after all. It doesn’t use fatty acids like the other organs, and will only use ketones if there’s no glucose around. I’d be surprised if cooked starch didn’t play a role in human brain evolution as well. It’s one of the most commonly eaten foods by contemporary HGs.
I agree. And the authors of the paper discussed cooked tubers. But the brain took a growth spurt before the advent of cooking, so at least that much of the increased cranial capacity came from meat eating. I don’t know how much of primitive man’s caloric intake came from starch and how much from animal sources, but from Cordain’s classic troll through the Ethnographic Atlas (a database of all contemporary hunter/gatherers), the average contemporary hunter/gatherer got 65% of calories from animals and 35% of calories from plant sources.
I had to look up “ineluctable.” To make sure I’d understand it, I had a burger patty first.
The guy thinks he’s a comedian.:-)
@Obvy
The carb content of even unsweetened plain yogurt is around 20g per cup because of the remaining lactose in the milk that it is derived from. Interestingly, my local grocery chain carries their own brand of low carb yogurt that is only 3g of carb per cup. To do this, they have replaced the milk with water, milk protein, whey protein and cream. They use small bits of fruit and Sucralose to flavor and sweeten it. It also contains active bacteria cultures. It’s quite good.
@JD
Johanson makes the point in his book: “Lucy: The Beginnings of Humankind” that the most primitive of our human ancestors, while being small of stature and cranial size, had pelvises nearly identical to modern humans, and thus had our same bipedal ambulation skills. He dispelled the notion that there was ever a hominid that was “awkwardly bipedal.” Given this and the fact that non-human small brained carnivores are quite adept at hunting, it would be a mistake to assume that early hominids were not.
Truly fascinating article, Dr. Eades. Much appreciated.
Excellent blog Michael. Shouldn’t the corollary be true ie do small headed people have larger hearts, gi’s or whatever. Are the record holders of say the 5000 metres more small headed, lb for lb, then there fellow competitors due to perhaps their larger hearts?
I don’t know that the Kleiber line is accurate enough to apply to individuals vs applying it to groups.
@Allen and Dr. Eades
I have, in the past, made extremely sour aged kefir that, i’ve heard anecdotally, breaks down a greater quantity of lactose than yogurt. Dr. Goldberg in “Four Corners Diet” asserts that there are four grams carbs remaining in yogurt after culturing and even less in sour kefir. He claims that he has tested this himself. HOWEVER, if he is correct, and if those four g carbs are lactose, could the remaining sugar be present as galactose and glucose and still negatively impact blood sugar?
I’m trying to assess whether or not it is possible to include kefir and, to a lesser extent, whole plain yogurt in a low carb diet. I’m just not sure how to “count” the carbs in these foods.
FYI, I can still only see the first few lines of each comment.
Working on it.
I am at least glad that they didn’t just go rollicking down that much loved (of anthropologists, anyway) blind alley of “big brains are necessary to be Great Hunters”. Phtaah. However, big brains MAY just get the girl… (I like that hypothesis, myself. I’m a female that likes smart men that like smart women, but that also bring home the bacon ;->) But we aren’t discussing WHY the big brain, just the possible HOW of the big brain.
There is indeed, food for thought here. (Forgive the pun. Never mind, I love puns. I never miss the O’Henry pun-off in the Great Republic’s capital city. The highest expression of the lowest form of humor… Humor for the masses.) Thanks for giving us this tasty new morsel to chew on! (I can’t HELP myself!)
Wallflower
Glad you enjoyed it, er, at least I think you enjoyed it.
Superb article.
I have noticed in this post and in most others a disturbing number of typos and other mistakes. I thus volunteer, as an experience proofreader, author and book collaborator, to proof your future postings. In fact, I’d be honored.
Thanks again for such outstanding and interesting pieces. Your content puts most medically oriented blogs to shame.
Do like everyone else does and proof them after they’re up. I’ll be happy to make all the changes as you find the errors.
The question “what about big cats, and wolves keeps coming up”… I would say in the mammalian kingdom, it is fairly obvious that dogs and cats have more intelligence than guinea pigs, and chipmunks etc… Ditto dolphins and whales. Omnivores like chimpanzees, bears, minks, ferrets, foxes, martins, even rats, seem to have exceptional problem solving skills when compared to a deer or a bovine. Beyond that, it is obvious that the human/primate genus, would be leaps and bounds past other mammals without meat, but when you add that to the equation you get something extraordinary: a human being.
Excellent article!
Tim was right about Facebook: PITA! I have no idea how you even have time for these amazing posts – and responding to comments! I am toasting your “expensive tissue,” and am glad you are feeding it meat!
Thanks. Meat eating is the only way I could survive the constant battle.
Great post, I had heard of the ETH but this was a great review of it. Still waiting with baited breath (yesterday was sashimi day and dessert was ikura) for an update on your world-changing project, hope it’s going well. But no pressure, eh.
Here’s another book for your spare time, if you haven’t read it yet: _Primal Body, Primal Mind_ by Nora Gedgaudas. The Drs. Eades are quoted in a couple of places. There’s a fair amount of convergence with PP, GCBC, Paleo but also chapters on leptin, mTOR (she appears to be a fan of VLC CHRONish protein restriction) and the relationship of nutrition to specific psychiatric disorders which I hadn’t seen in that much depth before. Good writing, lots of references, the editing could have been better but not bad for what appears to be a self-published work.
I think I got this book somewhere along the way, but haven’t read it yet. I’ll dig it out and take a look.
The very next post will be the revelation of what we’ve been working on. I do think it will be world changing in a way. But we’ll have to wait to see. God knows, we’ve spent enough time on it.
Thanks Dr. Eades. This really answered some of the remaining questions I’ve been asked, but have yet been unable to answer, regarding our cooked meat eating origins. Despite how this may sound, I’m not actually discussing religion here but merely being a bit tongue in cheek (don’t think to ill of me) . . .
In response to Phillis’ comment about how we were biblically vegetarian, when Adam and Eve stray by eating from the tree of knowledge, God says:
In the sweat of thy face shalt thou eat bread, till thou return unto the ground (Genesis 3:19, KJV).
Essentially, they are condemned to bread! Even in the old days it was known that agriculture was essentially a punishment.
I don’t think ill of you. I’ve used that very verse myself.
Another great article, Dr. Eades. In all honesty, the only proof I need that we are meat eaters is to watch my three year old attack a plate of yummy, greasy, bacon…she is a paleo baby and has the big brain and straight teeth to show for it. I had a friend who was a vegan and raised her child as such. We are no longer friends because (in her words) I’m an evil animal eater. LOL. Her child was ALWAYS sick and cranky, and was allergic to everything from peanuts to wheat. At one year old, the baby didn’t even have the muscle mass to pull herself up to standing on the sofa, meanwhile my kid was running around the house on her sturdy legs at 10 months. I think its such a shame, when I see other toddlers drinking skim milk and eating crackers. Those poor babies are just starved for fat and nutrition.
I am also so glad to have yet ANOTHER article to show people how I keep my hourglass figure while eating chili burgers with extra cheese (hold the bun) and meatloaf! Vegan friend, last I saw, still looked pregnant….sometimes the answer is right in front of you, but you still can’t see it!
Thank you for such an enlightening article. It’s funny though. Back in the early 1980s I took a number of grad courses in human paleontology, just for fun (we did flint knapping and everything!). I was so taken with everything I read, I ended up acing every test, much to the chagrin of the paleontology major who sat next to me who was only getting Cs.
Anyway, I remember reading and talking about this theory back then, so it’s not new to me. I’ve always “known” that the brain is an “expensive” organ and the only way to “pay” for it is to give it the highest-quality food available … meat. Never a doubt in my mind. I’m glad to see this theory getting the light of day again.
Hmmm. I wonder what made it fall out of favor for a while. Regardles, glad it’s back and glad you posted on it!
EXCELLENT post!
Dr. Eades: I’ve been a fan of yours since discovering the diet issues in “Good Calories, Bad Calories,” only last October — regrettably much too late in my 6 decades; however, your advice has worked wonders in my health (lost about 4 inches of visceral fat so far, not to mention other improvements). THANK YOU very much. I want you to know that your focus on science and proper epistemological methods is much appreciated by this layman, and especially that you translate the science issues to layman terms. May you and yours keep up the good work for many years to come. As Spock would say: “Live long and prosper.”
— Rob McVey, Markham, Ont.
Thanks very much.
Regarding the bible, the whole bit about Cain the farmer killing his brother Abel the shepard, was his jealousy that god accepted the sacrifice of animals from Abel but not the produce from Cain! So what do we take from that?
It’s pretty obvious to me.
@ Tim: Going vegetarian does shrink the brain. Lack of B12.
Nice post (if you are a fan of anthropology). You are totally backed up in the thought that we evolved a larger brain by eating meat — there seems to be almost no question of this. I hope the intelligent readers of this blog realize that just because we evolved eating a particular food (ie, meat), this does not mean automatically that eating meat is optimal for longevity. Eating some meat and animal fat is almost certainly longevity promoting, the question is in how much? I’m very happy though that your article dismisses the typical vegan notion that we are not compatible with eating meat, which is a ridiculous notion.
Something I have never seen talked about on these forums is possibly the ‘elephant in the room ‘ re human evolution.
If hunger were undoubtedly our ancestors’ constant companion, and once early human groups developed, then a form of tribalism would have ensued.
There would have been constant danger from other larger predators, but probably the greatest danger would have been neighbouring hostile human groups..competiing for scarce resources.
Up until quite recently cannibalism was common in parts of the world, and an accepted part of both diet and a consequence of hostilities. I have read where it is not unheard of in some chimpanzee groups.
I wonder how this might have affected human dietary evolution?
If true, it probably made us smarter since we had to out think other humans and not just animals. Would have made our brains grow fast.
Hey Mike, I’m glad you decided to post about this article. I had to read it several times to understand certain parts of it and I could see how the journal may have decided that it was too technical… On the other hand, that’s why they have other people who read through and write a summary (though not as thorough as your presentation here), highlighting their ‘masterpieces’. As you said, chances are it wasn’t how technical the article was but how controversial. I told you your readers would love it!
Anyway, with respect to brains getting larger, a little after Protein Power LifePlan was published, the book “The Omega-3 Connection” came out, written by Andrew Stoll. Among other things, in a chapter about evolution, he explains some of the theories surrounding the enlargement of the brain but his take in on fat consumption, perhaps over other nutrients. After reading Aiello’s article (and aided by your very elegant presentation of it), it rather easy, at least for me, to see how eating more fat could have resulted in increased brain size; the food that was most available where it all began for us humans was fish and shellfish… animal foodstuffs that contain plenty of protein and fat.
You wrote above about muscle mass not increasing metabolism, however, muscle is metabolically more active than fat is it not? I mean, because muscle is always ‘hungry’ for energy to maintain its mass, hence the recommendation of getting our muscles in good shape so their ‘hunger’ for energy can be supplied by our stored fat. Even without a metabolic rate as high as the brain, perhaps muscle contribution to overall metabolic rate shouldn’t be entirely discounted. Your recommendations on exercise since Protein Power to ‘The Cure’, seem to emphasize the fact that muscles contribute a great deal with the way we ‘dispose’ (in a good way) of stored fat since muscles are avid users of fatty acids as an alternative fuel for their metabolism, at least those muscles that work through aerobic metabolism. Any thoughts on this?
Thanks again for this elegant presentation of Aiello’s article!
Since I knew you had read the Aiello article, I was keen to get your take on my presentation of it. I’m glad you liked it.
There is no question that muscle is metabolically active, but it’s just not as much as you would imaging. I found this out when I wanted to do a piece a few years ago about how many extra calories one would burn by packing on a few pounds of muscle. I went to the primo exercise physiology text and looked up the metabolic rate for muscle and did the calculations and discovered that an extra pound of muscle burns just a few extra calories. I don’t remember how many extra, but I do remember that I was stunned that it was so few. I redid the calculations several times (including rechecking the figures in the book and going to other sources to confirm the factors) because I simply couldn’t believe what I was seeing. Try it yourself and let me know what you find.
@Obvy re: yogurt & low carb
Two words: Go Greek
I like Fage’s Total.
@ Dr Mike – Thanks are inadequate expression of my appreciation for all the great work you do, especially this blog. So I’ll just have to keep buying more of your books.
Thanks for the kind words. I really appreciate them.
@LCforevah: My take on the Cain and Abel story is that it was a tale of two cultures. Pastoral herders vs the Neolithic farmers. Told from the point of view of the herders, it is teaching story about what is acceptable for sacrifice…. meat and blood. Not plants.
Do I have a few jokes about vegetarians coming up!
I always said carbohydrate made us fat, sick, weak and stupid. Mike, don’t let the veggies read this or their brains won’t be able to handle it! I’m happy to be a carnivore, it allows me to surpass all my vegetarian friends in intellectual endeavors! You know what vegetarians say, if you can’t be smart, at least be politically correct! That last one made me laugh out loud.
Thanks Dr Eades, I enjoyed that post.
I’ve always felt that this was the case, thanks for giving me the ammo I need!!
“Yes, that nonsense about meat putrefying sets my teeth on edge every time I see it.”
Me too!! Also when people talk about colon “cleansing”!
@AJ…Another thing that “sets my teeth on edge” is that pregnant women are being told to keep fat as low as possible! And 2 yr old being changed to low fat! Do these people not understand brain development needs fat??
Luckily, my own daughter (who just got married) HAS listened to what I’ve preached and is currently trying to educate her friends!
- – - Tom Naughton, 22. September 2009, 10:23
– - – I had to look up “ineluctable.” To make sure I’d understand it, I had a burger patty first.
Words like that have a magnetic effect on the author’s eyes. When re-reading and editing, as he closer to the word, his eyes accelerate and skip right past the blatant typos earlier in the sentence so that he may stop and marvel at his creative patois.
Fascinating post Doc. Thanks! (Plenty of typos still though, keep editing.)
Hey Todd–
You wrote “Plenty of typos still though, keep editing.” Are you talking about my writing or yours?
See above:
“When re-reading and editing, as he closer to the word…”
As he closer to the word?
I read something once about people living in glass houses, but I can’t remember the rest of the quote.
I’ll always cheerfully admit to and fix any typos I make. When I write these things, I’m writing like a maniac, and when I’m through, I go back through, sort of. I’m so ready to have it up and be done with it that I don’t do the thorough re-read and edit that I should.
I have to count on my faithful readers to point these typos out to me.
I suspect we’ve begun an evolutionary divergence whereby vegetarians will develop longer intestinal tracts at the expense of brain matter, eventually becoming a separate species.
When they do become a separate species, I wonder if they’ll taste like chicken.
Another first time poster but long time reader and follower.
Very interesting correlation between eating meat and brain growth. However I think that environment must have played important part as well. When I was 13 y.o. I broke my leg. It was put in cast for about six weeks and once the cast was off I have noticed that the injured leg lost almost half of the muscle comparing to the non-injured leg. I assume that due to that limb being immobile the body’s energy preservation system kicked in and reduced the size of unused muscle tissue. Thinking of our ancestors when they started eating meat their body realised that it did not need same amount of energy for digesting meat as it was needed for plant food. So naturally there digestive system got smaller in size. The question is why was that extra energy diverted to brain and not to some other part of the body and would our brains grow if the meat was easily obtainable food source? Physically comparing to other animals such as big cats we are not that impressive. As we lived in groups killing or retaking already killed larger animal was necessary to survive. This brought us in face to face with other predators who competed for the same food source. So the humans had to create strategy and develop the tools to effectively obtain meat without becoming a diner for some other predator. Demand for meat created the need for thinking and that bit of extra energy that was previously used for digestion was diverted to the brain and presto, over the two million years we become most successful predators on this planet.
The point of “The Expensive-Tissue Hypothesis” is that we’ll probably never know the ‘why’ but we can make a pretty good guess at ‘how’ our brains were enabled to enlarge.
I had to look up “ineluctable.” To make sure I’d understand it, I had a burger patty first.
Tom, at least you got it with the a burger patty, it took me a whole lot more than that!
Dr Mike, i could never understand the transition of pirmates to monkeys. If there is a forward progression, how come there is no backwards movements in nature? In other words what would take us humans to become monkeys again, vegetarian diet ,lol oops did I just say that?
I don’t think it can go backwards.
Interesting, since vegetarians believe that not eating meat is a more cerebral and highly evolved.
I do think humans evolved to eat meat, but as to why we acquired the larger brain is a little like which came first, the chicken or the egg. Is the larger brain, smaller gut and shorter digestive track a direct result of eating meat, or was it a necessary outcome of being physically ill-equipped as hunters; not having speed or razor sharp teeth and claws to rip apart flesh. The compensation became a larger brain and thus, hunting smarter.
You say there were other primate groups that socialized and hunted, but whose brains had remained small; Why would this be if it was simply a matter of eating meat? Is it possible that a particular colony due to a certain hardship, possessed a little more will,,, determination,,, consciousness, and as a result were rewarded with a little more brain… a little less gut.
you know what convinced me to leave my vegetarian lifestyle and eat meat again? when i noticed that when i cooked vegetables and grains i had no reaction the cooking aromas but whenever i smelled meat cooking my mouth would immediately begin to water!
love your blog!
best,
ida
– You wrote “Plenty of typos still though, keep editing.” Are you talking about my writing or yours? —
Both! My tail is firmly wedged between my legs, though it proves my point. This blog software filtered out the big smiley grin I inserted at the end of that sentence. So much for trying to be funny.
I thought it was funny. I very seldom comment on other blogs because I don’t have time as I’m always busy dealing with comments on my own. But one day someone forwarded me a blog post that I couldn’t resist commenting on. The jerk who wrote it was so pompous (and I don’t even remember now who it was) that it made me sick. I took him to task in a comment, basically called him an idiot, and as a final flourish I pointed out a few typos he had made. Of course, when my own comment got posted, I had a bad typo in there myself. I used their for they’re. Or maybe it was the other way. I was so mortified I repressed it. And, of course, the jerk pointed it out just as I pointed yours out. So I feel your pain.
– When they do become a separate species, I wonder if they’ll taste like chicken. —
I hope so, but I suspect they’ll taste like asparagus and smell like brocolli. A defense mechanism evolved to protect them against us carnivores.
“I thus volunteer, as an experience proofreader, author and book collaborator, to proof your future postings.”
Roger, now I must volunteer to proof your proofreading as I am an experienced editor.
Thanks for the comments Mike. You know I had to try to check some numbers myself… though not very thoroughly tonight. I did find, however, a couple of references that suggest that muscle metabolic rate is indeed ‘not all that’, and it may be overestimated in most cases. In one reference (Am J Clin Nutr 2006;84:475–82) [http://www.ajcn.org/cgi/reprint/84/3/475], Robert Wolfe suggest that “every 10-kilogram difference in lean mass translates to a difference in energy expenditure of 100 calories per day, assuming a constant rate of protein turnover.” That’s only about 10 cal/kg muscle (or ~5 cal per pound of muscle!). The other reference, a bit older (Obes Res. 2001;9:331-336) [http://www.nature.com/oby/journal/v9/n5/pdf/oby200142a.pdf], the authors propose a classification scheme founded on body composition level (whole-body, tissue-organ, cellular, and molecular) and related components as the resting energy expenditure predictor variables. Rather technical but if some of the equations are applied to muscle, then we find that muscle the daily metabolic rate for muscle is just about 6 calories per pound per day, not very far from Wolfe’s predictions and very low indeed!
I can see how this could lead to the notion of ‘exercising is a waste of time’. While the increase in metabolic rate is modest at best (or right out low…), at least is higher than the metabolic rate of a similar weight of fat, which is about 2 calories per pound per day. Perhaps the lesson is that the right kind of exercise (resistance in this case, and probably more on the heavier side of weight training) improves body composition by burning more calories than fat in the hours after exercise and by preserving lean body mass while dieting for weight loss. In any case, certainly there may not be such thing as three extra pounds of lean muscle burns about 10,000 extra calories a month as I seem to remember from “Power of 10: The Once-a-Week Slow Motion Fitness Revolution”.
I’ll still take those very few extra calories per pound of muscle if that keeps my extra fat from accumulating!
Thanks again!
With all due respect to your gorilla readers, I must say that eating meat also made the female members of our species soooo much more attractive. IMHO, of course.
Very interesting post, thanks for putting up Part II.
I think you covered my particular interest in your reply to Alex:
@Dr Mike: “The point of “The Expensive-Tissue Hypothesis” is that we’ll probably never know the ‘why’ but we can make a pretty good guess at ‘how’ our brains were enabled to enlarge.”
My interest is that the ‘why’ could be any combination of things in a chicken and egg sort of way.
For example, a group of hominids could have suddenly found themselves in a niche where meat was easy to get (even with small brains) and very plentiful. After a while their digestive tracts could have shrank since there was no selective pressure for more digestive ability. This would have freed up resources for the brain to grow larger and more complex and energy hungry assuming this gave a survival/reproductive advantage.
Or it could have gone the other way around. Some selective pressure led to larger brains (for example hunting or social drivers), but only those with more efficient digestive tracts could survive due to energy requirements, which meant the survivors gravitated towards meat eating.
And of course it could be something in-between, co-evolving. Multiple paths result in falling on the line of ETH. I read your article twice and I don’t think I’m disagreeing with anything you said, correct me if I’m wrong.
You’re right. The ‘why’ could be almost anything.
“Do like everyone else does and proof them after they’re up. I’ll be happy to make all the changes as you find the errors.”
Ah, Dr. Eades is much too indulgent and I’d much rather he spend the time on more productive endeavors. To those who have nothing else to do but to point out minor typos, I would suggest that you keep a scrapbook of your finds and review them from time to time to keep yourselves happy. Dr. Eades isn’t making these errors out of ignorance; given the substance of the posts, who cares if he misses a letter as his fingers fly over the keys? Give it a rest.
I really don’t mind. I would much rather have my typos pointed out so that I can fix them. That’s the nice thing about a blog post – it can be corrected.
Actually–and I need to start taking notes when I run across this stuff, I can’t remember the source–cats are held to be the next most-intelligent animal after primates. By whom, I really don’t know, and I don’t know how they measure it, but generally, carnivores seem the more intelligent vertebrates overall.
It could be that because cats don’t have opposable thumbs and can’t walk upright, that limits their options insofar as how much neato stuff they can do with their intelligence. But believe me, they do think. Even housecats are very, very smart. Mine almost scare me sometimes.
Oh, and a few comments up, someone posits that we could have found an easy source of meat at some point and then selected for smaller guts afterward. It is thought in certain circles that proto-humans went from bug-eating to scavenging kills at some point. I’m not sure how that would work; don’t lions eat up just about every part of the critters they down, or do they leave leftovers? We’re built for picking bugs apart, not for taking meat off bones, so maybe our first tools were meant for bone-scraping and then we figured out they worked like lions’ claws. I don’t know, but it’s an interesting idea.
You’re right. The ‘why’ could be almost anything.
Elaine Morgan’s TED talk on the aquatic ape hypothesis is pretty interesting:
http://www.ted.com/talks/elaine_morgan_says_we_evolved_from_aquatic_apes.html
Vadim:
“Dr Mike, i could never understand the transition of pirmates to monkeys. If there is a forward progression, how come there is no backwards movements in nature?”
There are no forward or backward movements in evolution. A gene mutates, the mutation doesn’t kill the organism before reproduction occurs, and presto, you have a new variation. It’s not an “improvement,” it’s not a “step down,” it just… is.
Only some primates evolved into monkeys. Others evolved into lemurs and apes and so on. They all just sort of branched off in different directions–in the sense that reproduction *does* have a direction and you can never go home again. Apes were never monkeys–they were always two different groups. We’re apes too.
I don’t remember how it used to be classified but these days I think our order is divvied up into “dry-nose” and “wet-nose” primates. Apes are dry-noses. I don’t know why. Scientists are weird.
Hey, Dr. Mike, I just watched the Elaine Morgan talk — at around 9:30 in, she explains why humans are the only humans with subcutaneous fat (other primates — and middle-aged humans who haven’t read your new book — store their fat around their visceral organs.)
The South Sea Islanders used to refer to the product of a raid against another island as “long pig”.
I read this in a book at the of eight called The Coral Island by R M Ballantyne. The hero was a boy called Ralph who knew enough to save his younger companions with milk from green coconut and being able to build a raft. It was a schoolboy Robinson Crusoe.
As a result I built platforms in trees, became a river swimmer and eventually relived one of Ralph’s experiences when I dived in the Caribbean!
The other South Sea survival nugget I picked up while a young book omnivore came from The Kon-Tiki Expedition in which the raft crew began to catch fish and assuaged their thirst from the salt free fish liquor in a period when they had not replenished their water supply from rain. They also ate their fish raw, and as far as I know ingestion of fish is not improved by cooking. I notice that the ETH paper did not make any reference to fish eating or the Aquatic Ape hypothesis.
I have never forgotten “long pig”!
Don’t think a vegan would taste like beef until (s)he evolve a rumen and become a true herbivore.
I’m curious about how we get nutrients from vegetables. A big part of the cell walls in vegetables is cellulose that we can’t break down. But we still can get some nutrients from the veggies. Is this because of the cell wall not being 100% cellulose? But if we can “open up” plant cells to get the nutrients inside, how come unchewed peas and corn get straight through the GI intact?
Cooking helps. It’s difficult to get a lot of nutrients without cooking. Some are available, but not as many as after cooking.
Thank you . I had come across references to the notion of energy conservation/ brain size before but never really understood it. Kleiber is new to me. Now a light bulb has gone on in what passes for my brain.
Possibly related to this (and where I first came across the notion) is the human inability to manufacture
vitamin C. Again another energy exchange.
Eating meat that has vitamin c in it (nearly all animals produce their own) would suffice for hominid needs.
Not having to manufacture vitamin c is energy conservation.
Culturally it may have some bearing on our typical aversion to eating carnivores and cannibalism.
As one of my peasant neighbours comments “Actually I really am a vegetarian, its just that I prefer my vegetables processed into meat before I eat my greens.”
Cheers
Dr Mike:
I am wondering if you have heard about a exciting study being conducted by Ohio State University called the “Global History of Health Project”. You can read about it here:
http://global.sbs.ohio-state.edu/
A quote from the site: “This project creates three large databases to reinterpret the history of human health in Europe from the late Paleolithic era to the early twentieth century. During this period, human health and welfare were transformed enormously by the transition from foraging to farming; the rise of cities and complex forms of social and political organization; European colonization; and industrialization. With a trans-Atlantic network of collaborators, we will undertake large-scale comparative studies of the causes and health consequences of these and other dramatic changes in arrangements for work, living, and human interaction”
A smaller study has already been conducted, and a book is available (see the site for details).
Interesting. I hadn’t heard of this. Thanks for the link.
Even if it’s less of a metabolic advantage than we all thought, I’ll take the smaller volume from muscle mass over the blobs of fat any day. Besides, a certain amount of fitness allows us to face the challenges of daily life; muscle isn’t just smaller, it’s useful.
Great post, Dr Mike.
Just as carbohydrates cause us to get fat and eating meat causes us to lean up, eating just meat can also help an anorexic to gain muscle. Meat seems to get our bodies in balance.
Check out this link.
http://forum.zeroinginonhealth.com/showthread.php?tid=2564
>Dr Mike, i could never understand the transition of pirmates to monkeys. If there is a forward progression, how come there is no backwards movements in nature? In other words what would take us humans to become monkeys again, vegetarian diet ,lol oops did I just say that?
>>I don’t think it can go backwards.
Isn’t it just a case of usefulness versus uselessness? If a mutation provides an advantage, it tends to stick. If that once-advantage ends, the mutation can atrophy. I’m pretty sure that there are species that “lost” their eyes, for instance, when they became dark-places dwellers. No doubt parts of our bodies have devolved over the ages, too.
Mea culpa, Katy and the others who noticed my gaffe. I didn’t say I could type or write well myself, just that I could find mistakes in others’ writing. But that’s what happens when you don’t proof your own work…
As I have learned over and over.
Here’s a question: if muscle isn’t as strong a calorie burner as previously thought, can we lose weight by exercising our brains? On days when I’ve spent several hours writing (hard brain work!) I’ve often thought anecdotally that I saw a reaction the next day on the scale.
Crazy? Any thoughts?
If this could be proven significant it could be world changing indeed!
Hmmm. Would be interesting to check out. Are most heavy thinkers thin or fat or is there a correlation. First thing to do would be an observational study to set the hypothesis.
@ aint got no head: You are in a Mobius strip, my friend. We’d look good to you however we turned out!
Dr. Mike — thanks so much for such a valuable resource. My husband and I are avid followers of the PPLP approach, and I read (and re-read) your blog faithfully. I can’t tell you how much I’ve learned from your thoughtful and insightful writings.
Now to a specific question. Yesterday a small blurb appeared in the lifestyle section of our daily paper (the Toronto Star) covering the press release of a new study from UT Southwestern Medical Center here: http://www.utsouthwestern.edu/utsw/cda/dept353744/files/548055.html. This one has me baffled. Some of the statements seem to run contrary to what I’ve read in your writings (and others).
Such as: “Findings from a new UT Southwestern Medical Center study suggest that fat from certain foods we eat makes its way to the brain. Once there, the fat molecules cause the brain to send messages to the body’s cells, warning them to ignore the appetite-suppressing signals from leptin and insulin, hormones involved in weight regulation.”
And: “Though scientists have known that eating a high-fat diet can cause insulin resistance, little has been known about the mechanism that triggers this resistance or whether specific types of fat are more likely to cause increased insulin resistance.”
Finally: “Though scientists have known that eating a high-fat diet can cause insulin resistance, little has been known about the mechanism that triggers this resistance or whether specific types of fat are more likely to cause increased insulin resistance.”
Of course, I could be completely misunderstanding this press release, even though it presumably is targeted at lay readers rather than at scientists. Is this one of those dreaded “observational” studies from which conclusions are being incorrectly drawn? Is something else going on here?
Thanks for any insights — Pauline
This study involved injecting different types of fat directly into the brains of laboratory animals. Not a lot that one can conclude from the data when applied to humans who eat their fat, which makes it way through the GI tract and the blood before it gets to the brain. Big difference between that and injecting it directly in. Here’s a post I did along similar lines that is much more reflective of what really happens.
I checked out your drawings and had to comment on how nice they are. I was trained as a portrait artist so I especially appreciate them. Although it is not uncommon for creative people to have interest and talent in more than one creative field, it is rare to find someone with real talent in each field; I have met many people who delve in art, writing and music, but not really talented in all 3. I have met only one person who was exceptionally talented as an artist, writer and musician. With your exceptional talent in art and writing; and interest in music, I am surprised you have never pursued music more, like take up an instrument. Instead, you have put a lot of effort into interest such as searching for buried treasure and disappearing from charging bulls (fascinating). I think the voice in your head was saying ‘musician’… not ‘magician’.
I do play the guitar, banjo, and violin. But not well. At least not as well as I draw and sculp. I love music, but I didn’t grow up in a musical family. We didn’t have a stereo system or even a record player until I was a junior in high school. My guitar and banjo skills are self taught, but I had some formal training on the violin. Come to think of it, though, my art skills were all self taught as well.
@Elizabeth, everything you said is true and a great anthropological explanation. But the Genesis story is only of one culture, and across time, cultures and geography, every where you go on this planet, the correct sacrifice to a god has almost always been meat. I think this speaks to its value to human life everywhere as opposed to the relative lesser value of produce.
Hi Dr. Mike,
Have you read “Catching Fire: How Cooking Made Us Human” by Richard Wrangham? Seems like a book that could expound on your post.
I have read it.
“Dr Mike, i could never understand the transition of pirmates to monkeys. If there is a forward progression, how come there is no backwards movements in nature? In other words what would take us humans to become monkeys again, vegetarian diet ,lol oops did I just say that?”
And then what about rabbits turning into zebras? And then pigs having lambs? Where are all the “monkeys in the middle” so to speak?
http://www.drdino.com
More on vegetarians having car accidents and other early deaths:
This is a must see video:
Pantox Laboratories
4622 Santa FE St
San Diego, CA 92109-1601
Charles a. Thomas, Jr. PhD of Pantox Laboratories, San Diego, was interviewed on the video “Living to 100”, (which I have a copy of in my library), a subject of longevity that as one ages, and continues to drive an automobile well into old age, the most likely that person WILL have an accident, which could be fatal. A stunning example of this fact was the natural hygiene couple, who are called the “munchkins” of Florida (which are described as being somewhat short of stature,). Long term raw eaters Ruth and her husband who now live in St. Petersburg, Florida, were living in Miami, Florida. At the 1999, State O’Leona park gathering, Ruth told me about their car accident and it was the reason they sold their private home with avocadoes trees in the back yard to move to a retirement facility in St. Petersburg, Florida. According to her story, they were on the way back from their granddaughter’s wedding when their car was hit on the passage’s side, she suffered a broken hip and had to have surgery. She recovered, slowly, she told me, but dreaded having to go to the hospital. Ruth wrote a book about recovering one’s eyesight using the Bate’s method, which I have a copy of in storage. As far as I know, they are still alive. Although I no longer am in touch with the older NH folks.
And, then there was long term vegetarian, 91 yr. old, never married and child free, Edith of my home state. She suffered a terrible accident midday going to the local bank. Her 1988 Olds was totaled. She survived with minor cuts. Still living alone, she now relies on the local mass transit and walks everywhere if she can. Three weeks after the accident, she fell in her year and hurt her sciatic nerve and broke her wrist. At that time, she was having a caretaker living in part time. Now in 2009, she is doing OK. I have not seen her in a while, though.
In Spring 2006, prior to Vihara Youkta’s death, while I was visiting with her and Victor, she told me that long term raw vegan African-American Karyn Calabrese, owner of Karyn’s Fresh Corner in Chicago fell and broke her knee caps. Don’t ask me how she (Karyn) fell or where. I am only telling you what I was told while visiting Victor and Youkta in Simms, Arkansas at their farm. I am sure they would not lie to me. (smiles)
In the book, The Live Food Factor” by Susan Schenck, she reported on an elderly man, who was long term raw eater who died as a result of a car accident injuries. Was he this author’s husband, How I Conquered Cancer Naturally by Edie Mae? I stand to be corrected on this one.
I wanted to let you know, that long term vegan, 51 yr old, divorced and no children, well known Nina Domby, R.N. (retired) and massage therapist died of ovarian cancer, while I was at college in Texas, two years ago. I found out when I returned to my home state, seeking her for a massage. Everyone at the spa was shocked that I did not know she had died. I was at the University of Texas (south Texas tropics area) for a year, and did not keep in contact. Ms. Domby had a large massage practice and worked at the local spa on the weekends as well. She was a hard worker, it was sad to hear the news. I must add that she was overweight as a vegetarian and never exercised. I do know this for a fact. She owned a farm in the rural part of my state, and always attended the vegetarian potlucks.
Phuq the Eejits who out-point type-o’s.
Reading Engrish from 400 years ago one will get the point …namely that whilst we may feel in our limited hominoid time frame that lingo is a steady state thang i.s spelling grammar context etc.It is assuredly not so pointing out the spelling when one has gotten the meaning is just some nasty little primate dominance put-down..hence the first sentence.
EMAIL 12/05
Re: [INHS] Goldberg on Living Long
>1) Having family ties
>2) Active life (but not athletes)
>3) Major dietary factor is “undereating” i.e. not engaging in luttony. This is the major dietary factor
>4) Some type of spiritual beliefs/practices (no particular religion)
>Being a “Hygienic Professional” is particularly stressful for a number of reasons including the poor understanding both the public (and so called >”Hygienists”) have of us. Very little support, legal hazards, unrealistic expectations from clients, etc. I hope to address some of these problems in a future
INHS newletter article. >Paul A. Goldberg, M.P.H., D.C., D.A.C.B.N.
With best wishes,
Paul A. Goldberg, MPH, DC, DACBN
Director, The Goldberg Clinic, Clinical Chronic Disease Epidemiologist , Diplomate of The American Clinical Board of Nutrition
http://www.goldbergclinic.com
John wrote:
“Isn’t it just a case of usefulness versus uselessness? If a mutation provides an advantage, it tends to stick. If that once-advantage ends, the mutation can atrophy. I’m pretty sure that there are species that “lost” their eyes, for instance, when they became dark-places dwellers. No doubt parts of our bodies have devolved over the ages, too.”
As I understand it, a mutation does NOT have to be immediately useful to “stick.” Stephen Jay Gould has written about this frequently. Consider that fish that has a little wormy thing that grows out of his head that attracts other fish for him to feed on. Cool adaptation, huh? But this didn’t happen all at once. The end result definitely proves useful, but what did the vestige of this appendage do? How was that little nub immediately useful?
Mutation is simply mutation and it is the process of evolution. I’ve always thought of it in exactly the opposite terms to what John wrote. Evolution results from mutations that are NOT DISadvantageous. Make sense? If a mutation (like being born without a limb) provides a distinct DISADVANTAGE, especially in the sense of survival and attracting mates to pass along the mutated gene, it will likely not be passed along, and evolution doesn’t “happen.” If it does no harm in terms of survival and reproductive ability, it MIGHT be passed along even though it is of no value at the “moment.”
The long neck of the giraffe is indeed useful in eating leaves higher up in the trees, but what good is a just slightly longer neck, which an ancestor of the modern-day giraffe surely possessed?
Gould also wrote about species that have indeed evolved to be capable of sight, then evolved to NOT be capable of sight, and back again.
So, now I’m confused.
@Tim: I’m curious about how we get nutrients from vegetables.
@mreades: Cooking helps. It’s difficult to get a lot of nutrients without cooking. Some are available, but not as many as after cooking.
Why are so many people telling us that we should get as many of our vegetables as possible RAW and WHOLE ? What’s up with that?
They’re clueless. There is a movement to eat everything raw. People in the forefront of that movement believe that raw is better than cooked. But it often isn’t, especially with vegetables. It’s difficult to extract all the nutrients and calories from vegetables when they’re raw. If you are interested, a good book laying this all out (and mentioning “The Expensive-Tissue Hypothesis”) is Catching Fire: How Cooking Made Us Human. The book stresses how cooking as compared to eating food raw (een meat) makes more nutrients available. It pretty much lays waste to the eat-raw bunch.
but what good is a just slightly longer neck, which an ancestor of the modern-day giraffe surely possessed?
It would have been good to eat the foliage of the time.
Trees respond to evolutionary pressure too.
If it does no harm in terms of survival and reproductive ability, it MIGHT be passed along even though it is of no value at the “moment.”
Or it might be passed on, but not expressed. Here’s a shot of a snake found in China last week. A birth defect caused a vestigial foot to be expressed, with which the snake could climb.
a href=”http://www.telegraph.co.uk/earth/wildlife/6187320/Snake-with-foot-found-in-China.html”>Snake with foot found in China
@Obvy wrote:
“Specifically, i’m interested in where the disconnect is between the approach of the Paleolithic diet regime and the approach of the WAPF.”
I suggest you check out this post by Kurt Harris of PaNu, the essence of which is “metabolism over food re-enactment”
http://www.paleonu.com/panu-weblog/2009/8/31/raw-paleo-and-food-re-enactment.html
OT: Banjo? Awesome. What style? I’ve been slowly trying to teach myself bluegrass style. Make that VERY slowly.
A 5-string banjo, my own style, I guess. I just figured out the chording and kind of pick my own style. I haven’t even picked up a banjo for a few years because mine was stolen in a robbery at our house in Boulder. My guitar and (fabulous sound) 150-year-old violin got nabbed, too. I’ve replaced the Gibson guitar but not the violin.
I think the book “The Vegetarian Myth” nails down all the reasons why vegetarianism is wholly unnatural and why agriculture is mostly responsible for the destruction of much of the biosphere.
Not to belabor it, but I’ve thought of a bit more about my hypothesis that we can vary our metabolism through different levels of mental exertion just as we can for different levels of physical activity (perhaps even more). We all know from brain scans that neural response is much greater in intense activity (like taking a test) than passive activity like watching television. I personally recall walking out of various law school exams feeling physically exhausted.
But the question – how much exertion/how many calories burned? Probably a simple experiment to calculate the calorie burn of a human lab rat doing various mental tasks versus physical activity. We’ve all seen the tables (how many calories burned walking/running/swimming per hour) but the comparison is to physically resting. That’s because “everybody knows” that physical exercise uses calories but anything you do sitting down is unimportant in that respect. Your information about the brain being more high-powered than muscles seems to put that common wisdom in doubt.
If the number is significant — big mental exertion burns big calories — I can think of two immediate implications. First, under the Taubes principle, people doing mental work are going to get hungry, and should budget calories accordingly. In addition, this further amends the advice to weight-loss wannabies to toil away at the gym. Perhaps the library or video arcade would be just as good or better.
Really fun musing (with knowledge that I’m probably wrong) — thanks to another great Dr Eades post.
Also an artist Mike? Maybe my boss is right… she keeps telling me that it is not uncommon that people in science usually have a strong artistic side as well… Who knows… I play piano and organ (or anything with a keyboard for that matter), paint (though that hasn’t happened in eons), use to sing in an a Capella quartet and enjoy relaxing doing graphic design… My ex-wife used to say that because of the musical ear, I was able to learn languages without too much difficulty as well. Or maybe our brains just want to compensate with something ’softer’ to contrast the science side and keep us sane! I would have loved to learn how to play guitar!
It’s never to late to take it up.
Perhaps one can learn good writing skills; and one can learn to play an instrument, and become quite good with practice; but with regards to art — you either got it or you don’t. You can’t be taught the ability to capture a likeness. It you go into school without an ounce of talent, you still won’t have any when you come out.
so, should intense mental activity be considered a valid and effective weight (fat) loss method?
That would be nice, but I don’t think it would be very effective.
With respect to WAPF vs. Paleo, the focus of WAPF is traditional foods, including traditional foods of the neolithic era, with an emphasis on dairy being raw and grains and beans being fermented. As it happens, I am lactose tolerant and have no acute sensitivities to any foods. But, in eliminating (for the most part) grains, beans, and dairy from my diet, I have been able to see how they are still suboptimal foods, despite humans eating them for 10,000 years and me being relatively well adapted to eating them. I am, of course, in complete agreement with WAPF’s position on dietary fats, but with its heavy emphasis on neolithic foods, I think WAPF is primarily valuable for people beginning to shift away from SAD diets. I think if people are interested in truly optimal nutrition, they’d do well to ditch WAPF and shift to a more paleo diet.
Any idea why your guest post on Tim Ferriss’ blog has been removed? (Assuming it’s not a glitch of some kind in my browser.)
I don’t have a clue, but here is a permalink for it that still works.
Dr Eades,
Great post, but I think there are some missing ingredients. Alot of people are asking why didnt other carnivores evolve big brains like us and im not really buying into the “selective pressures” thing. I think the special ingredient is cooking. We are afterall the only animal on the planet that is both a meat eater and a cooker.
I know you say “But the brain took a growth spurt before the advent of cooking,” but I really have my doubts here. Raw meat for the most part is extremely unpalatable, requires considerably more chewing than cooked meat, and pathogen contamination risk is much higher. Further, raw meat is significantly less satisfying after consumption. Just try eating a piece of raw bacon, its a fascinating self experiment.
You will find yourself chewing it for ages and then finally when you “feel” its ready to swallow your more than likely to just spit it out. Raw fish is indeed much more palatable than raw land animal flesh, so perhaps the art of fishing came before cooking which would help bridge the gap bewteen the meat eating brain spurt and cooking. Dairy is important point I think, I find all dairy extremely palatable and satisfying, digestion feels really good. A glass of milk goes down much better than a glass of fruit juice.
It may not have clicked with some people about dairy aswell, but that alot of animals seem to instinctively prefer cheese. Everyone “knows” mice love cheese and eat it, but cheese is not a natural food. A mouse would never find cheese in the wild. I remember seeing an experiment done with a squirrel, putting different food sources in closed chambers where the squirrel would have to go around and taste each food sample and then finally choose one, the options were nuts, bread, sweets, jam, cheese and insects. Guess which one the squirrel finally chose? It was the cheese! Amazing, given again the squirrel would never find cheese in the wild.
So to sum it up, I agree that meat eating was indeed a huge step in the development of big brains and that humans are no doubt meat eaters by nature, but if you look at the anecdotal evidence, there is certainly ’something’ missing. Why havent other carnivores got big brains? The answer for me has got to be cooking.
P.S. Once again great post, its clear you worked very hard on it, surely this is one of top blogs on the net
Forgot to mention I really enjoyed the little discussion on the metabolic costs of organs VS muscle mass. It too has been my experience that muscle mass doesnt boost ones metabolism as much as it is claimed.
After I started commuting to work by cycling, I noticed a significant jump in my apetite, however despite putting on a thick layer of muscle on my legs and buttocks, I still need to avoid the carbs to avoid weight gain. Gary Taubes was right on the money when he said exercise doesnt help weight loss it only makes you hungry.
I don’t think anyone has answered this concerning cats: “If that is the case then either Kleiber’s law is violated and they have a lower metabolic rate OR there is some other metabolically expensive tissue that makes up for it (instead of brain matter).”
Musculature: They move much faster than us, can jump higher, etc. Their evolutionary solution to the game of life was physical, ours was mental.
Heart Rate: Average human 72 bpm. Average cat heart rate is 160 bpm (120-200).
Most cats do spend more than half the day sleeping.
After a Sydney-wide ineluctable ostent — for Lo! the sky turned blood red and all took on a Martian hue — the Six Sennight Remedial Treatment for Elimination of Superfluity of the Central Circumferences for the Young At Heart (Though Not in Years) has arrived through the good offices of the local dak wallah. At last, God-like physical perfection will soon be mine (cue evil laughter: Mwaaaah Hah Hah!).
Can’t wait to see a photo of the God-like physical perfection that shall ineluctably be yours. Get to work.
What about eating salmon or fish oil instead?
http://bit.ly/10zBGD
What about the prostaglandins in meat vs. fish?
Salmon or fish oil instead of what?
There are no prostaglandins to speak of in either meat or fish, only the raw materials, i.e., fatty acids, to make them. Wild game and grass fed beef has plenty of omega-3 fats.
I was just about to recommend the Wrangham book! It’s a pretty cool book…it’s so sad how much more anthropologists and food historians (I’m studying it currently and they all mention the importance of fats and proteins for the population) just “get it”, and how our nutritionists are in the dark.
I’m not sure if it’s been asked before in the comments (if it has, you don’t have to answer), but what do you think of the effects of low-carb on um…ethnic groups? I admit there’s some personal concern involved…I’ve tried over and over but low-carbing makes me carb-binge. My happy carb range is 100-140, any lower and I get the binge feeling, and any higher I feel ecky. I was wondering if being Chinese might have anything to do with it? Or maybe rice and fruit carbs (my main sources) are better than wheat carbs?
I was just thinking, if northern Europeans can develop lactose tolerance, when fresh milk hasn’t been consumed that long (well, comparatively speaking), then maybe certain populations have a little higher tolerance for carbs.
Thank you for your time!
I’ve had patients from multiple ethnic groups following low-carb diets, and I’ve seen no major differences between how well people from the various ethnic groups do. I have nothing to base this on other than my own personal experience with a lot of patients, but I think there are more differences between individuals than there are differences between ethnic groups in general.
Wow, that was a really clear explanation of research, not typical for the average blog.
I do have a question. I have read this in other places and have found it very convincing. However, I read a book recently that adds a piece to the evolutionary puzzle, and I’m wondering how much this piece changes the meat vs. veggies equation. The article above clearly points out that in order for our brains to develop, our guts had to give, and in order for that to happen, we had to get more nutrients from our diet with less work on our digestive system. This means our diet had to change. The book I read is called Catching Fire: How Cooking Made Us Human. It’s a fun read (totally and hilariously demolishes raw foodists), and is very enlightening around the evidence for when cooking was introduced and the role that played in our evolution. He doesn’t make a vegetarian vs. carnivore argument in the book, he only talks about evidence for cooking, and how that improved the quality of our diet by allowing us to get more nutrients out of our diet, taxing our GI system less, allowing that to provide the give so our brains could take. Sound familiar?
So I’m wondering this. How do you make the argument that it was cooking plus meat, rather than cooking alone, that gave us the nutritional ease of digestion we needed to develop our brains? As I said, he made his argument on the overlooked importance of cooking alone and doesn’t really touch this debate. I believe a case can be made that even with cooking you can’t get enough out of a vegetable-based diet to allow for this kind of evolution. But I don’t know if there’s evidence for this suspicion of mine. Have you read any research that specifically addresses this?
Anyway, great post, great explanation. I found you through Ferriss and I’m glad I did.
Cheers
I’m glad you found me, too. Welcome aboard.
Catching Fire is an interesting read, especially as he lays waste to the raw foodists. He references The Expensive-Tissue Hypothesis in the book as do the authors of The Expensive-Tissue Hypothesis mention cooking as a possibility. The first rapid expansion of brain size came prior to the advent of cooking, so it would have been difficult for cooking to have been responsible for that one. Maybe cooking was involved in the second expansion, maybe not, but we know it wasn’t involved in the first.
@kris – Betty Edwards begs to differ with you. Capturing a likeness can be taught. See “Drawing on the Right Side of the Brain.” Can you imagine if we taught reading this way: “only 1 or two natural readers in a classroom – comes from a family of readers – has mysterious reading talent that regular people don’t -” – that is how we talk about drawing and Edwards proves it can be taught like reading can.
Hey Doc,
Great post… just makes so much sense. On another note, I am not sure if this was posted yet, but my hubby found this buried in the Globe and Mail online. It seems that researchers are finally catching on to the link between Vitamin D and cancer in northern latitudes:
http://www.theglobeandmail.com/life/vitamin-d-casts-cancer-prevention-in-new-light/article756975/
Maybe there is hope for us canucks!
Statins degrade the brain and heart.
table sugar degrades the liver and clogs the arteries
wheat degrades the digestive system, befuddles nutrient absorption, addicts the brain
frankenstein fats alter (for the worse) all the membranes of 100 trillion cells and wreck havoc on steroid hormone manufacture and balance.
“Gary Taubes was right on the money when he said exercise doesnt help weight loss it only makes you hungry.”
Oh, pity the poor overweight persons on The Biggest Loser who are consuming 1200-1500 calories per day and are exercising their 200-400+ lb. bodies for 4-5 HOURS per day! They work out until they vomit. And the diet/chef expert they just featured is, of course, anti-fat, going on about the high-fat chicken caesar salads that are baaaaad. Sad. (so why am I watching it? I’m showing my grandson what NOT to do).
@LCForevah: Absolutely. Don’t disagree with you there at all.
@Todd,
HG Wells already wrote that story. It’s called the Time Machine.
Dr Eades, thank you for this article. This is a fascinating subject.
Some comments on other commentor’s comments:
It doesn’t make sense to make assumptions about the diets of ancient human hunter-gatherers by comparing them to modern peoples – the most fertile areas of the planet are now used for agriculture, and the remaining hunter-gatherers mostly live in marginal areas. Studying the diets of modern humans on the African savannah, Australian aborigines or Indians in the Amazon is not necessarily going to tell you much about homo erectus hunting mastodons. They were different creatures living in a different world.
It’s not reverse evolution, but there were branches of our family tree that went in other directions. The robust australopithecines were true vegetarians – they had massive jaws and ridiculously huge molars for crushing seeds and grinding coarse plant material. They had small brains and no doubt huge guts to process this diet. They had a bony crest like a fin along the tops of their skulls as an attachment for powerful jaw muscles:
Australopithecus boisei skull
Evolution did not go in a perfectly straight line with us as the goal. The path meandered and went off on dead-end tangents. I’ve always found it fascinating that, until very recently, there were different species of hominid living at the same time.
Many comments make the assumption that we developed big brains to be better hunters. The article and replies to the comments repeatedly say this is not the case – we don’t necessarily know what the pressure was to grow bigger brains, or what was cause and what was effect. Being smarter would make us better hunters, but that doesn’t mean that this was the reason. The point is not why we grew bigger brains, but how we managed to do it.
Thank you again for writing this.
The protein requirement of mammals is reflected in the protein content of their respective milks. Vegetarian mammals tend to need less protein and have lower concentrations of protein in their milk than do carnivorous mammals. For instance, cow’s milk is about 3.5% protein and goat’s milk is 2.9%, whereas cat milk is about 9% protein, and dog’s milk is a whopping 11%. Even omniverous rats have about 10% protein in their milk. How much do humans have in breast milk? An average of 1.1%. Some analyses have shown as low as .9% protein, and yet human infants can double their weight on it in six months. This is far more relevant than a grandose hypothesis about human evolution.
Even if your figures were correct, your statement that “the protein requirement of mammals is reflected in the protein content of their respective milks” is false. But, due to the fact that you’ve obviously been listening to way too much vegetarian propaganda, your figures aren’t even close. The amount of protein in human breast milk is about 6 percent, not an average of 1.1 percent. I don’t know what the protein content of cows milk is, but it is greater than that of human milk, which means that it must be more than 6 percent, not the 3.5 percent that you list. Cows have practically no requirement for dietary protein, so how does that square with your theory? Sadly, your grandiose hypothesis is the one that is flawed.
No! You’ve got it wrong. 6 or 7 percent is the amount of protein in milk based on percentage of calories! I’m talking about per volume of weight. In other words, in a 100 grams of human breast milk, there is about 1 gram of protein. And in 100 grams of cow’s milk there is about 3.5 grams of protein. Look it up. You’re way off! And to say that cow’s have practically no requirement for dietary protein? For goodness sake, a calf grows from 60 pounds at birth to 600 pounds in a matter of months. What do you think that weight is composed of? All fat? There’s bone and muscle and tendon and ligament and everything else that requires protein. I don’t know who you are who submitted that answer, but you are embarassing yourself.
No, you’ve got it wrong. No one uses a figure for the amount of protein as a function of the total weight – most of which is water – of a liquid product or a solid product such as meat, for that matter. The figures used are either the calories from protein (or other macronutrient in question) as compared to the total calories in the substance under question or the absolute amount of a macronutrient without taking calories into account. Most scientific papers are written using the first method; those of us counting carbs use the second.
I’ve never seen so many errors compacted into one small paragraph in my life.
Where do you think the cow that grows from 60 pounds to 600 pounds in a matter of months gets the protein once it is weaned? Where does this protein come from if the cow is grassfed? Grass contains virtually no protein, so how does the cow build its muscle and tendon and ligaments and skin and hair? I’m going to let you figure that one out because I’m not responsible for either your ignorance nor your education. But you should think on it to see if you can come up with a reasonable explanation. And while your pondering the answer to that easy question, perhaps you should also ponder the quote below from Mark Twain. It sums up you situation to a tee.
It is your gross ignorance that is on display, not mine. And I’m through with the debate. I’ll be happy to provide you all the space you want to display it further, but don’t count on me to reply.
Ralph Cinque is referring to the percentage of protein per weight.
Even wikipedia’s article on milk lists the percentage of protein per weight:
http://en.wikipedia.org/wiki/Milk#Nutrition_and_health
According to nutritiondata.com 3.7% fat milk (standard milk) is 22% protein when going by % of calories and not weight.
http://www.nutritiondata.com/facts/dairy-and-egg-products/70/2
For any animal, cow or human, the muscle, hair tissue etc is made from protein. Cows have a large body mass and like any other animal their tissue frequently breaks down and needs to be replaced with protein. “Calves…. double their weight in 47 days (as opposed to 180 for humans), grow four healthy stomachs, and weigh 300 pounds within a year”.
Why would we need to consume more than 6% protein after being weaned if this is the percentage required for the human baby which is the period (I need to confirm this) where we grow the most rapidly.
“According to the World Health Organization (WHO), the average 150-pound male requires only 22.5 grams of protein daily based on a 2,000 calorie a day diet, which means about 4.5 percent of calories should come from protein. (WHO recommends pregnant women get 6 percent of calories from protein.) Other nutritional organizations recommend as little as 2.5 percent of daily calories come from protein while the U.S. Food and Nutrition Board’s recommended daily allowance is 6 percent after a built-in safety margin; most Americans, however, are taking in 20 percent or more.”
Taken from http://www.theengine2diet.com/the-diet/#qa41
http://www.theengine2diet.com/the-diet/#qa41
And I ask you, where does the protein to fuel this growth come from. Hint: It ain’t from the grass that they eat. Get with your buddy Ralph and see if you two can figure it out.
I always find it ironic that the capacity in humans to feel remorse for eating animals would not exist at all if we hadn’t begun to consume animals.
I figured it out and learned something new. I knew that cattle have microorganisms that break down cellulose into simple sugars, but I didn’t know that cattle get most of their protein from microbial protein synthesis. The human stomach and small intestine secrete proteolytic enzymes, so the human diet obviously requires foods that actually contain protein. Since cattle can synthesize protein from the non-protein components of their diet and humans can not, it doesn’t make sense to compare humans and cattle in terms of required protein intake. What I’m not sure about is where the microbes get the nitrogen to make the protein, but I would guess that it’s the nitrates that are naturally present in grass; rumen is a liquid, so I wouldn’t think that there’d be enough air in it for nitrogen fixing bacteria.
I see you decided to do Ralph’s homework for him. You’re almost there. Read this paper to get a little further along. I’ve got to do a long post on this subject sometime.
I always find it ironic that the capacity in humans to feel remorse for eating animals would not exist at all if we hadn’t begun to consume animals.
This is the most brilliant observation about vegetarianism, ever.
To Alex – The microbes in the rumen get nitrogen from the nitrogenous materials contained in the plant material they consume. Simply put, legumes (clovers, alfalfa, etc) “fix” nitrogen via micro-organisms that live in nodules on their roots. This nitrogen is used by the plant. When that plant tissue is eaten the animal’s microbes can utilize it. Urine and dung from the animal, as well as decaying plant tissue, release nitrogen back to the soil where grasses, and other plants which can’t fix nitrogen, can use it for their growth.
Tom – Agreed!!
pete
This is Ralph Cinque, and for those interested, I continued the debate with Dr. Eades on my own website, and I’ll give you the link:
http://www.1to1vitamins.com/news/2009/artl7584.html
There’s no need to debate whether it’s proper to look at protein as a percentage of calories or protein as a percentage of weight in milk. The point is that EITHER WAY YOU LOOK AT, HUMAN MILK IS THE LOWEST PROTEIN MILK IN THE WORLD!
And the notion that cows only survive as vegetarians because of all the bacteria they grow is nonsense. The world is full of vegetarian animals and of many different kinds, both ruminant and non-ruminant. It’s nonsense that only ruminant animals have the capacity to be vegetarians. Besides, unlike cows, we humans do not live on grass. We’re definitely not like them. We can eat fruits and nuts. And we have many vegetables that are much less coarse and fibrous, and far more digestible, than grass. We can also eat whole grains and legumes. Hey, the above is what I eat. And I’ll bet serious money that I can lift a greater percentage of my body weight than Dr. Eades can. I’m almost 59, and I presume we’re close in age. C’mon, Doc. I’m chalking up my hands.
Beware. A note of warning. If you spend any time on the above website you risk serious brain damage. After reading a little of it myself, I now understand where Ralph is coming from.
I just checked out the link that you gave to Alex re ruminant digestion. Wow!
How do you find the time to find this stuff.?
Love this blog. Keep up the good work.
Certainly, this is all fine. I have no reason to dispute the research. However, I do find the conclusion very myopic for the following reasons:
1. Meat may have been the most efficient source of nutrition in that phase of our evolution but the same effect could have been achieved with the right combination of plant-based foods. We simply did not possess our current level of knowledge then.
2. If we had also consumed more of the plant-based superfoods we know about now, probably our evolution would have been even more efficient.
3. Why should we justify eating an animal-based diet now simply because it worked in the past. With our expanded nutritional knowledge, we can now achieve the benefits of a meat-based diet plus more.
4. The food we eat is no longer simply the food we eat. In this stage of our evolution, it has significant political and ethical, etc connections. We can maintain excellent health on a plant-based diet and also satisfy ethical considerations. Perhaps this is in fact the next stage of our evolution.
I would urge you to move beyond retro-focused justification of meat-based diets and consider what nutrition would be most effective for our continued evolution, both physically and spiritually.
I’ve only skimmed the comments so I hope I’m not repeating something that has already been said.
It’s been a while since I was an undergraduate anthropology major (finished BA in 1999), so no doubt the exact theory has moved on somewhat. However, one important more-or-less accepted idea regarding food sources for early hominids (e.g. Australopithecines) was that their ability to make and use tools allowed them to scavenge more food, especially bone marrow, from the leftovers of other animals’ kills. This was because they had the mental ability and the manual dexterity to make and use tools that would allow them to effectively crack open large bones which would have been difficult for, say, a hyena to get at. There is also the possibility that they were able to scare away other scavenging animals, but I’m not so sure about that.
Below is table comparing human to other mammalian milks (based on weight, but the results would not be different if you looked at calories). Notice that human milk is not only the lowest in protein (by far), it is also the highest in carbohydrate- by far. 7% sugar in human milk is comparable to watermelon. So, human milk is the sweetest of all milks. And a human infant can live on (sweet) breast milk alone for two years. Imagine, meal after meal, being conditioned to a sweet taste. So, it’s not surprising that babies naturally gravitate towards bananas, cantaloupes, etc. because its a continuation of the sweet taste they’re used to. Humans also have the most dense concentration of sugar-detecting tastebuds on the tips of our tongues. Cats, (to which Dr. Eades compares us to) have no ability to detect sugar- at all. Check out the link. You can speculate all you want about the remote past, but this isn’t speculation: it’s reality.
http://www.washingtonpost.com/wp-dyn/content/article/2005/07/24/AR2005072401107.html
COMPARATIVE ANALYSIS OF MILKS:
• Human: 3.8% fat; 1% protein; 7% lactose
• Cow: 3.7% fat; 3.4% protein; 4.8% lactose
• Rat: 10.3% fat; 8.4% protein; 2.6% lactose
• Dog: 12.9% fat; 7.9% protein; 3.1% lactose
• Rabbit: 18.3% fat; 13.9% protein; 2.6% lactose
Ralph,
This is very interesting. I wonder if the diet of the mother effects the macronutrient concentration? So could a woman eating a very low carb, zero sugar diet possibly produce less lactose by volume than a woman who eats the Standard American Diet?
Also, if you look at protein not as energy but as the building blocks, I think the fact that these other animals reach adult hood so much more quickly than we do could explain why they all have a higher percentage of protein in their milk. If the cow, for example, physically matures 3 times as quickly as a person, that would account for the fact that they were eating 3 times as much protein.
Just a thought. I am interested to hear what Dr. Eades has to say!
And to Kym, read Vegetarian Myth, by Lierre Keith. Please, please read it. It’s wonderful, and addresses each of your points exhaustively and poetically.
For 20+ years, I ate a diet very much in tune with what Ralph suggests, foolishly believing all sorts of new age hippy nonsense, and completely ignoring my body telling me in no uncertain terms that it was not the right nutritional approach for me. Reality is that a high-carb, predominantly vegetarian diet spikes and crashes my blood sugar and makes me fat and lethargic. Reality is that a diet of meat, veggies, and a little fruit sates my appetite, doesn’t spike my blood sugar, and effortlessly keeps my body weight normal. One thing I learned in all of this experience is that it’s best to listen to the body and not just blindly follow some external set of beliefs.
Ralph,
Most vegetarian propaganda lists the components of human milk by weight to deliberately create a misleading picture. You are incorrect to say that listing them by calories gives similar results.
Fat has 9 calories per gram, carbs and protein each have 4, so according to your numbers human milk has over 20% more calories from fat than from carbs. On top of that, much of the lactose is actually there to feed the beneficial bacteria in the baby’s gut, which turn it into lactic acid and keep an acidic pH in the digestive tract – this prevents the growth of harmful bacteria which the baby’s immune system is not ready to deal with.
Figures for the nutritional content of human milk are averages, because it can vary widely according to the mother’s diet and also for the same woman over time. It also varies considerably even during a single feeding – it’s initially quite thin, but as the breast empties it becomes much thicker and contains much more fat. I believe that there are even different names for the early and late milk.
The quantity of protein in its milk is related to how quickly a species grows. Humans are among the slowest-growing animals on the planet, so human milk has proportionately low levels of protein.
It’s also misleading to compare human milk to some of those other animals, because we are such different creatures. Humans nurse frequently throughout the day, so human milk is much less concentrated than the milk of many other animals. Cows would be somewhat similar. The other animals you mention, dogs, rats and rabbits, have mothers who must leave their babies alone in the den/nest/warren for much of the day while they are out hunting or foraging, so their milk needs to be more nutritionally dense than human milk, because those babies have fewer meals and consume much smaller quantities per day, relatively speaking. Humans normally have only one baby who gets the mother’s undivided supply of milk. The other animals have litters of four, five or more siblings who must share the limited supply of their mother’s milk (which is why all of those animals have more nipples than we do) and at the same time grow very rapidly, as they must be capable of living on their own once they have been weened in a few weeks’ time.
Humans might indeed have a sweet tooth, but in the wild, locally-native berries and fruit would be about the only way to indulge it, and these would only have been available for a few weeks in autumn in most parts of the world (and, as has been pointed out in this blog, we’d be competing with birds and other creatures for those same goodies). A sweet tooth would encourage us to eat them when available, but it would be impossible for sweets to be a regular component of the diet before the relatively-recent introduction of agriculture.
Fruits did not always exist in their present, high-sugar forms, either – the fruits we have today are the result of thousands of years of selective breeding of plants that have been collected from all over the world, and bear little resemblance to their smaller and sourer ancestors.
(m)eat and die
Let’s not get off-point here. And the point is that if a human infant can grow and develop and double its birth weight in 6 months on a diet of nothing but breast milk, which has either 1% protein by weight of 7% protein by calories (and both figures are low) then why should I, an adult human, who is not growing at all, who is just hovering, maintaining, require a high protein diet?
And to answer Bryce, yes, the composition of a woman’s milk does fluctuate depending on her diet, but usually within a narrow range. It’s genetically determined. It’s not like she can double the amount of protein in her milk by doubling the amount of protein she eats.
To Paul, you’re correct that breast milk delivers more calories as fat than as carbohydrate. Over 50% of the calories are from fat. Happy? But what you said about the lactose primarily feeding the bacteria, you will have to provide references for that. On Wikipedia it just says:
“Infant mammals nurse on their mothers to drink milk, which is rich in the carbohydrate lactose. The intestinal villi secrete an enzyme called lactase (β-D-galactosidase) to digest it. This enzyme cleaves the lactose molecule into its two subunits, the simple sugars glucose and galactose, which can be absorbed.”
Contrary to what you said, not much lactic acid is formed in the gut of a healthy infant.
And all this philosophizing about the conditions way back when, how the fruits were back then-as if you know. Here in Texas, we have a wild Texas persimmon tree, and it makes an edible fruit that is very sweet. There’s not much to it because it’s small, and the pit is large, but Man o Man, it is sweet. And if it were less sweet, a person who depending on them would just eat more of them. And as far as competition from the birds, etc., well Man had plenty of competition towards getting animal food as well.
Listen, I don’t say that everybody has to be a vegetarian. However, I am saying that, if you’re smart, you’ll realize that you have no good reason to eat a lot of meat. Maybe eat some in rationed amounts either because you like it or because you think you need it. But you fill up on plants.
And to those poor folks, including Lierre Keith, who are crying the blues because they think they were ruined by vegetarianism, I say: there, there, now. Here in Austin, Texas, we’ve got a vegan fireman, Rip Esselstyn. And believe me he’s ripped. He looks like he could scale the Empire State Building with his bare hands. And when he’s not putting out fires, he’s competing successfully in high-level triathalons. Go ahead, tell him your sad story. Don’t worry; he’ll be compassionate; he’s a vegetarian.
LOL seba! I’ve been eating ONLY meat for 8 months now, after being very low carb for a decade! I’m a 41 year old male and, now in PERFECT health. I have CONVERTED my doctor from a “low carb hater” to an ABSOLUTE proponent to the healthiness of meat (and saturated fat!).
In 1999 I was 280 lbs, eating low fat and excersizing….now? 180 with little excersize and all meat.
I guess I’m just the exception though……
Come on Ralph! I’ve done the vegetarian gig, LONG ago….now I only eat meat….THERE IS NO COMPARISON AS TO WHICH IS “HEALTHIER”….That argument is moot.
The compassionate argument is another story, but relative to one’s beiefs…not facts.
You get me 20 “non roided” vegans, and I’ll get 20 “non roided” carnivores and we’ll line them up…I’ll show you the difference between “skinny” and “ripped”.
So, Ralph, because breast milk is the proper food for human babies means that it’s macronutrient profile is ideal for adults? Breast milk is high in sugar and fat– it’s supposed to make babies grow and get fat. That’s not something that most adults aspire to do. And the fattest babies I’ve seen are those who’ve had nothing but breast milk for at least the first six months.
Ralph, I do not live in the USA ,never have.
I have many USA friends .
They keep telling me stories about Texans.
You have demonstrated they are right.
@Kathy : Good point? Are you saying that formula babies are healthier then breast fed? If you think that so you need to speak to a real doctor they will disagree with you. Actually speak to a lactation specialist would be best.
Dr. Mike:
Your argument based on the book is we evolved faster by eating high levels of meat. Why has not lions and wolves evolved quicker? Why are indians so smart given most of them are vegetarian (history goes back as far as the 6th century)? Japanese are also vegetarian (well maybe pescatarian), and you see studies that on average they are smarter then westerners maybe over the centuries they have evolved quicker because they are doing it right.
I so agree as Lindsey also explains in 13 reasons why we must eat meat:
1. Eating meat is part of nature. We need to do everything the natural way. That’s why we never use modern appliances and computers or never slather chemicals all over our bodies in an indoor waterfall everyday. Besides, eating plant products is ENTIRELY unnatural.
2. Eating meat will make you strong. And that’s why strict vegetarian animals such as pandas, horses, and cows, to name a few, are such weak, skinny, scrawny, anemic, helpless animals. (http://www.veganbodybuilding.com/?page=bios)
3. Meat is the only true source of protein. We all know that the millions (and probably billions due to lack of money to afford meat) of vegetarians through time just collapsed and died from protein deficiency.
4. We should eat meat because it’s tradition. We’d be forsaking our culture if we didn’t. Where would we be if we ever forsook the time-honored traditions of slavery and forcing women to work in the home and denying them access to education?
5. God told us it’s OK to eat animals. It’s in the bible! And that’s why our society heartily condones infanticide (1 Samuel 15:3, Psalms 135:8 & 136:10, Psalms 137:9), child sacrifice (Judges 11:29-40, Genesis 22:1-24), polygamy ( Genesis 4:19), slavery (Leviticus 25:44-46), and putting people to death for working on the Sabbath (Numbers 15:32-36). It’s in the bible, the ultimate moral authority!
6. There is no point for animals existing unless they exist for us to use. And that’s why our raisons d’être would become completely null and void, and we would gladly submit to an intellectually and physically superior alien race who wanted to eat our own flesh. Might is right – the only valid way of life.
7. Farm animals would quickly overrun the world if we didn’t kill them to eat them. It’s a miracle a few billion people had the space to exist before we started mass producing animals solely for meat by forcing them to breed or artificially impregnating them by the millions daily (http://www.animalvisuals.org/data/slaughter/?y=2008). Animals were EVERYWHERE!
8. Animals want to be killed to feed us. You can tell by the way they act when it’s time to die. We as humans, too, always scream in terror and thrash about and try to run when we’re having a good time!! (http://www.meat.org/)
9. Our bodies are just like a carnivore’s! That’s why we have alkaline saliva to digest starches, which are strictly found in plants; a very long digestive tract so animal flesh, which has no fiber, can sit and rot for days; and very sharp teeth and claws for biting into an animal and killing it with our bare hands. We also can outrun most animals at our blazing top speed of ~25 mph and tackle them. We were designed to kill! Even our babies instinctually try to kill animals. (http://www.naturalhealthwizards.com/Ideal_Diet.pdf , http://www.youtube.com/watch?v=05zhL1YUd8Q )
10. Animals don’t have feelings. They are just big pieces of meat – big pieces of meat who just happen to cry and mourn for days when their young are taken from them (http://www.youtube.com/watch?v=_kM387cI4rk) or when they lose a companion of the same or a different species and excitedly dance when they see a beloved companion, human or nonhuman animal. Nope, all those are programmed, mechanistic, reactionary responses that are completely unlike our very divinely special human emotional responses.
11. Americans are so very vibrant and healthy from our meat-centric diet, which is why we have the some of the highest rates of cancer, heart disease, and obesity in the entire world. We eat more meat than nearly every other country in the world, so we are the healthiest. What would we do without it?
12. Most importantly, meat tastes freakin’ good. All of our morals are based on what our fleeting pleasures and hungers dictate us to do. That’s why we exalt serial killers, rapists, and pedophiles.
13. Eating meat is a sacred personal choice and right. Just as deciding to dump loads of contaminated animal waste in someone’s backyard and to unnecessarily and inefficiently use up untold amounts of fresh water is our very own personal choice that has no ramifications on anyone else in this world – human or animal. ( http://www.alternet.org/environment/134650/the_startling_effects_of_going_vegetarian_for_just_one_day/ , http://www.goveg.com/environment-WaterWeDrink.asp )
[http://www.veganise.me/13-reasons-why-we-must-eat-meat]
I believe the term for that is “link-baiting.”
Alex,
One terrible flaw in the argument that animals can get big and strong on plant matter is this:
Horses, Elephants, Cows, and other large ruminants get large and muscular while eating plants because the bacteria in their stomachs can digest the cellulose, and then the animals digests the bacteria. Humans Can NOT Do this. We have no bacteria in our stomachs, just our intestines. We can not digest cellulose (plant cell walls), which is why we call it fiber – it simply runs through you and you poop it out. The digestive track of a human is simply not the same as that of a strictly vegetarian creature. Period.
Japan, as a country, has progressively eaten more and more animal fat since 1970, and their levels of heart diseases have fallen in that time. Also, Indians are not all vegetarian, and heart disease is FAR more prevalant in regions of India that are predominantly vegetarian. Non-vegetarian areas of India have less than one 6th of the incidence of heart disease, even though they smoke more. These facts I have just put out are easily verifiable, and if you care to actually do the research there, you will, I promise you, find them to be true. I did my homework, and found this.
What makes you think Lions have not evolved? They are apex predators in their ecosystem, and their only threats (aside from poaching/human encroachment) are other lions. They have gotten really good at what they needed to get good at. So have we.
Finally, I hate to mess with the stereo types, but are you saying that Japanese and Indians are smart simply because the ones who come to the west to participate in academically rigorous material are smart? What makes you think there aren’t just as many dumb Japanese/Indians as there are dumb Americans? Just because all of the Indians that I know personally are smart people, doesn’t mean all Indians are smart. It could be that only the smartest decide to come and excell in American Universities. This is a really weak argument here Alex. I’d expect more from someone attempting to dismantle the overwhelming evidence that we are meat eaters as a species.
Alex, and I am being serious, on the basis of your last post you need serious psychiatric assistance.
Please for your own sake seek it out..
Best wishes.
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