A little over two years ago I wrote a couple of posts arguing that we cut our ancestral teeth on meat, and that contrary to all the vegetarian blather about colon length, tooth structure, etc., the archeological and anthropological convincingly demonstrates we were descended from meat eaters, not vegetarians.  (Click here and here for those posts.) A couple of recent developments have now inspired me to write a third.

First, I noticed in both talking with people at the Ancestral Health Symposium last August and attending a number of the talks that many followers of their own version of the ancestral diet are dismayingly including more and more carbohydrates.  And recommending more to their followers.

When MD and I wrote Protein Power in the mid 1990s, we used the Paleolithic diet as an argument for the efficacy of the low-carb diet.  If pre-agricultural man evolved in a milieu devoid of carbohydrate-dense foods, we posited, then natural selection should have culled those who didn’t thrive on such fare, leaving us, the descendants, powered by metabolic processes that performed better on protein and fat substrates.  If the rampant obesity and diabetes (we just thought it was rampant then) was a consequence of a diet we weren’t designed for, then switching to one that better suited us metabolically should produce substantial changes to the good.  Which it undeniably does.

I can’t help but recall the great quote by Dr. Blake Donaldson, who changed the complexion of his practice in New York after spending some time with Vilhjalmur Stefansson.  Wrote Dr. Donaldson in Strong Medicine, his book about an almost all meat diet:

During the millions of years that our ancestors lived by hunting, every weakling who could not maintain perfect health on fresh meat and water was bred out.

Now, it seems, many who have taken to the Paleo diet have started to drift from the Paleo-is-basically-low-carb paradigm into the Paleo-is-anything-that-isn’t-Neolithic paradigm.  And although Neolithic man grew all sorts of crops, most Paleo dieters consider only grains to be truly Neolithic foods.  Some Paleo dieters take it a step further and argue that since pre-agricultural man couldn’t have domesticated animals (other than perhaps canids of some sort), then he couldn’t have eaten dairy products.  So, those Paleo purists avoid grain and dairy products.  Both the dairy and non-dairy Paleo dieters, however, are starting to include larger amounts of carbohydrates – primarily starch – into their diets on the presumption that Paleo man would have eaten it.

I have no doubt that Paleo man would have been face down in a box of donuts had he been given the opportunity.  But he wasn’t.  Nor was he often presented with the opportunity to indulge in a carb fest composed of high-starch fruits and vegetables. Maybe in the fall when the fruit ripened (if he could beat the birds and bugs to it), but not much of a chance during the rest of the year.

(I am aware that Denise Minger put up a post not too long ago showing all the high-starch, high-sugar tropical fruits available in tropical areas, intimating that early man must have consumed these and, therefore, should have evolved to do okay on high-carb diets.  Problem with this reasoning is that archaic homo sapiens migrated out of tropical areas anywhere from 60,000 to 150,000 years ago and went through the crucible of natural selection in other less fruit-laden climes.  People of European descent certainly had ancestors who could not avail themselves of tropical fruits at any time.)

The second event driving me to write is a line out of a guest post on Richard Nikoley’s Free the Animal blog by Darrin Carlson titled “The Five Failings of Paleo.”  In Mr. Carlson’s own words, here is Paleo Fail #1:

We Don’t REALLY Know What Our Ancestors Ate. [Bold and caps in the original.]

I disagree for a couple of reasons.  First, we can be pretty certain what our European ancestors didn’t eat.  They didn’t eat dwarf wheat, Red Delicious apples, bananas, Bartlett pears or any other hybridized or tropical fruits commonly available today. As far as we know, there were no Paleo Luther Burbanks grafting and hybridizing plants to make them bigger and sweeter.  Our predecessors would have eaten whatever plant foods were at hand, which is pretty much what you still find if you go out in the woods today. They would have had to battle the birds and other wildlife to get to these fruits, and would have had them available only seasonally.

The second reason I disagree is alluded to in a way by Mr. Carlson in his explanation of Fail #1: Said he:

We have yet to find a magic phone booth that will transfer us back through time–Bill and Ted notwithstanding–to directly observe how our great-times-450-grandparents lived.

Actually we do have such a ‘magic phone booth’ available to us, or at least to those of us who know how to use it.  It’s an isotope ratio mass spectrometer, and its use has been refined over the past 30-40 years to allow us to peer back in time and calculate what our ancestors ate.

I learned about this ‘magic phone booth’ in the fall of 2000 in Hamburg, Germany where MD and I attended a great conference titled Meat and Nutrition.  After the last talk, on a cold, dreary, foggy, drizzly afternoon, MD, Loren Cordain and I lit out to  make a pilgrimage to Indra and the Kaiserkeller, the dives where the Beatles had gotten their start in the early 1960s.  We asked Michael Richards, a professor at the University of Bradford to join us.  On the first morning of the meeting, Michael had given a riveting talk on the use of stable isotopes to determine the diet of early man, and I wanted to find out more.

After roaming the Beatles early haunts, we decamped to a Hamburg coffee house to get warm.  I asked many questions about the stable isotope methodology and have followed the growing literature on it since.  Michael has turned into an academic superstar and is now at the prestigious Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, where he continues to publish his work on the isotopic analysis of the diet of early man.

Let’s take a look at the ‘magic phone booth’ of stable isotope analysis and see what it shows.  The whole notion is fairly complex so I’m torn between making its science simple enough for Homer Simpson to understand, which really doesn’t do the technique justice, or making it unnecessarily difficult. I’m shooting for something in between.

As most everyone knows, atoms are composed of protons, electrons and neutrons.  The number of protons gives an element its atomic number.  A given element always has the same number of protons but can have varying numbers of neutrons.  Carbon, for example, has six protons (and an atomic number of 6).  But the carbon atom can have 6, 7 or 8 neutrons.  All three versions are still carbon, but the atoms vary by the number of neutrons.  These different versions are called isotopes, so basically isotopes are atoms of the same element with the same number of protons but differing numbers of neutrons.  The atomic mass of an atom is determined by the number of protons and neutrons it contains, so although carbon always carries the atomic number of 6, carbon has three different atomic masses: ¹²C, ¹³C and ¹⁴C.

Carbons with an atomic mass of 12 and 13 (¹²C, ¹³C) are stable whereas ¹⁴C (pronounced carbon 14) disintegrates radioactively over time.  This radioactive decay is what allows scientists to determine the age of organic materials up to about 40,000 years old. The discovery of natural radioactivity of ¹⁴C and its usefulness in determining age garnered Willard Libby the 1960 Nobel Prize in Chemistry.  Although the unstable isotopes such as ¹⁴C have their uses, we are concerned here with the stable isotopes.  Primarily ¹²C and ¹³C and ¹⁴N and ¹⁵N (nitrogen 14 and 15).  From these four stable isotopes, we can learn a lot about the diet of early man.

Nuclear weapons started adding ¹⁴C into the atmosphere in the mid 1900s, so the average ratio of ¹²C, ¹³C and ¹⁴C have change slightly.   Since ¹²C and ¹³C are stable, there has been virtually no change in the ratio between them over time.  But the ratio of the two has been found to differ from one carbon-containing material to another.  For instance, carbon dioxide generated from marine limestone contains more ¹³C than does carbon dioxide generated from burning wood.  In general, marine sources have greater amounts of ¹³C than do terrestrial sources.

Just to make it a little more complex, when researchers run samples through a mass spectrometer to determine the ¹³C/¹²C ratio, this ratio is compared to an agreed standard.  Then the difference between the sample and the standard is called the relative ¹³C content, which is designated by δ¹³C and measured in parts per thousand. (‰)  So if the sample has a ratio less than the standard by 5 parts per thousand, it is defined as having a δ¹³C value of −5‰.

Don’t worry about all the above – just remember when you see δ¹³C from now on, it refers to the ratio of ¹³C to ¹²C.  Don’t despair.  It will be easier as we go along.

Of the dry weight of bone, a little over 25 percent is collagen, and it is collagen that is the tissue of choice for stable isotope analysis.  Virtually all of the carbon and nitrogen in collagen comes from protein, and since most protein in the human body ultimately comes from protein in the diet, the carbon and nitrogen isotopes in the collagen reflect the protein sources in the diet.  And since the stable isotope composition of collagen turns over very slowly, the ratios of carbon and nitrogen stable isotopes reflect diet over about an eight to ten year period.

Stable isotopes of both carbon and nitrogen occur in varying proportions in different foods, and these proportions are passed along to the animals, including humans, that ate these foods.  By knowing the proportions of the stable isotopes in various foods, we can determine these foods by analyzing the stable isotopes in human collagen.

Researchers are able to extract valuable data from the collagen of ancient bones.  Unfortunately ancient bones are not thick on the ground, and since a part of the bone has to be destroyed to perform the stable isotope analysis, these analyses are not done by the thousands.  Each time a skeleton or group of skeletons is unearthed, Michael Richards and other stable isotope researchers try to snare a little piece of bone and go at it with the mass spectrometer.  This kind of work has been done for several decades now, and the results – though painstakingly obtained one specimen at a time – are accumulating, and there is now a fairly substantial body of data.  And this data is remarkably uniform in what it shows of the dietary habits of our ancient European ancestors.

The δ¹³C and δ¹⁵N figures reveal different information about the diet of Paleo man.  Since the ¹³C isotope is found in greater quantities in the marine environment than in the terrestrial, a larger δ¹³C indicates a diet higher in seafood protein whereas a lower δ¹³C is associated with a diet composed primarily of protein foods from the land.  Researchers have accumulated considerable data on the δ¹³C of seals and other such animals that spend their lives in the oceans consuming other marine life to compare with the data gleaned from bones of animals living on the land far from the sea.  By noting how the δ¹³C from ancient human bone compares to these extremes determines whether the human dined on protein from terrestrial or marine sources of from a combination of the two.

The δ¹⁵N tells a different story.  δ¹⁵N basically tells us where an animal or human is on the food chain.  Basic plant foods maintain a fairly constant δ¹⁵N value.  When animals, typically herbivores, eat these plant foods, the stable N isotope in the plant food tends to concentrate by anywhere from 5-8 percent in the collagen of the animal.  So if the collagen of an animal is found to have, say, a 7 percent greater δ¹⁵N than the local flora, one can say the animal was an herbivore.  Animals that are known herbivores, when analyzed, fit this spectrum.

Any animal, including man, that dines on herbivores will have collagen sporting a δ¹⁵N that is about 7 percent greater than that found in the herbivores that are the meal, a fact confirmed by stable isotope analysis of known carnivores.  A super carnivore (for lack of a better name) that dines on other carnivores and herbivores would have an even greater δ¹⁵N level.

So, δ¹⁵N pinpoints us on the food chain while δ¹³C tells us whether the protein we eat is surf or turf or both.

Now that we have a full understanding of the ‘magic phone booth’ of stable isotope analysis, let’s take a look at what the data show.

The data taken as a whole show the following:

Early man was a high-level carnivore. (As was his distant relative the Neanderthal, who lived contemporaneously with ancient man in Europe.)  A higher-level carnivore, in fact, than foxes, wolves and other known carnivores.  The earliest anatomically modern humans got most of their protein from animals of terrestrial origin.  As time passed and the populations of large game thinned due to heavy hunting by both humans and Neanderthals, the human position on the food chain didn’t change, but sources of protein changed from all terrestrial to more and more marine (which includes fresh water fish, mussels, clams, etc., all of which have a similar δ¹³C as animals from the ocean).  Irrespective of whether the protein came from the land or the sea, early man occupied a super-carnivore niche in pre-agricultural days.

Here are a couple of graphics of stable isotope studies done by Michael Richards – one on Neanderthals; the other on early modern man – I presented at the Ancestral Health Symposium back in August at UCLA.

As you can see from this slide, the Neanderthal subjects were ranked a bit above the wolf and fox on the predator/meat eating scale.  As Michael Richards commented in the paper cited above:

…the European Neanderthal diet indicates that although physiologically they were presumably omnivores, they behaved as carnivores, with animal protein being the main source of dietary protein.

When we take a look at another study evaluating ancient humans, we see much the same thing.

As compared to the Arctic fox, you can see that early humans were way off the chart to the right.  Michael Richard’s commentary:

We were testing the hypothesis that these humans had a mainly hunting economy, and therefore a diet high in animal protein.  We found this to be the case…

The bulk of the stable isotope studies show both Neanderthals and ancient humans were, at their robust cores, meat eaters to the max.  What the stable isotope studies don’t show, is how much carbohydrate these folks ate along with their meat.  (Actually some stable isotope studies do show what kind of carbs in the sense that they can differentiate between grains and non-grains, but since there were no grains in Paleo times, that isn’t a concern.) But since we do know that wolves and foxes are predators that consume mainly food of animal origin, and we know that early humans have an even more carnivorous stable isotope footprint, it seems unlikely that these humans would have consumed many calories from non-animal sources.  Remember, natural sources of protein are virtually always associated with fat (copious amounts of fat if the protein is from large game and the entire carcass is consumed), so it’s doubtful there would be either the capacity or the necessity for complementing the basic diet of fat and protein with much carbohydrate.  But, nonetheless, even if our ancient ancestors did eat some carbs they could scrounge while in season, the stable isotope evidence clearly demonstrates they were not vegetarians.

If you would like to read more about stable isotope analysis for determination of the diet of early man, a good place to start is with the publications of Michael Richards.

Other good sources for basic information:

Katzenburg MA (2008) Stable isotope analysis: a tool for studying past diet, demography, and life history. In Katzenburg MA, Saunders SR (eds) Biological Anthropology of the Human Skeleton. (Hoboken, Wiley-Liss) 2nd Edition pp 413-441

Schoeninger MJ, DeNiro M (1984) Nitrogen and carbon isotopic composition of bone collagen from marine and terrestrial animals.  Geochim Cosmochim Acta 48:635-639.

Schoeninger MJ (1995) Stable isotope studies in human evolution. Evolutionary Anthropology 4(3): 83-98.

van der Merwe, NJ (1982) Carbon isotopes, photosynthesis, and archeology. American Scientist 70: 596-606.

..man, proud man,
Dress’d in a little brief authority,
Most ignorant of what he’s most assur’d…

From Measure for Measure by Wm Shakespeare

The web has been alive with commentary the past few weeks since Denise Minger lobbed her first cannonball of a critique across the bow of The China Study, the vessel T. Colin Campbell, Ph.D. rode to fame and bestsellerdom.  Seems like everyone is now jumping into the fray and gunning for poor Dr. Campbell, who early on in the fracas made a few halfhearted attempts to fight back but has now fled the scene.  I’ve been laying low watching it all play out, and so now figured it’s about time I add my two cents worth to the debate. But first a little history.

I met Dr. Campbell about ten years ago (five or so years before the publication of the popular book The China Study) when we both spoke at the same conference.  He was a nice enough man who spoke about the work he and his team had done in China gathering the data published in the massive 894 page monograph Diet, Life-style and Mortality in China (pictured above left).  As Dr. Campbell presented his data ‘demonstrating’ the superiority of a plant-based diet and demonizing protein of animal origin, I didn’t think much about it because the data was all in the form of observational studies, which, as all readers of this blog should know by now, despite often showing correlation don’t prove causation.  My lecture, which followed Dr. Campbell’s, was, as you might imagine, a lecture of a different sort.  Then we both sat on a panel after our talks and fielded questions.  And were both cordial to one another.

A few years ago, I became vaguely aware that Dr. Campbell had written a popular book on his work in China titled, appropriately enough, The China Study.  I assumed it pretty much mirrored his presentation I had watched, so didn’t rush out and grab a copy.  Over the past few years a number of people have asked about The China Study through the comments section of this blog, and I’ve typically answered that the data are all observational and so not really meaningful in terms of causation.

(Note: Throughout this post whenever I refer to the popular book Dr. Campbell wrote, I’ll call it by it’s title The China Study, and when I refer to the large study Dr. Campbell was involved with in China and was the basis for the monograph Diet, Life-style and Mortality in China, I’ll call it the China study.)

About a year ago, I wrote a guest post for Tim Ferriss’s The Four Hour Workweek blog.  It actually wasn’t a guest post as much as it was an excerpt of a chapter from our book The Six-Week Cure for the Middle-aged Middle extolling the virtues of saturated fat.  It was a popular post that has garnered to date 520 plus comments, many of them fairly spirited.  I agreed to answer a number of the comments and did so.  I noticed as I sifted through them that a handful were absolutely fawning of Dr. Campbell and The China Study.  Here is a sampling:

The number one study of diet and disease is the China Study. All other data points are slivers compared to the volume of data and statistical correlations that came from the China Study.

Have you read The China Study? Dr. Campbell points out repeatedly that none of the weight loss studies such as Atkins or South Beach diet follow any type of peer reviewed scientific method.

Tim…and to think I was such a big fan of yours. This is by far the weakest (and least cited) argument I have ever read on diet–especially increasing saturated fats. Half knowledge is a scary thing in the hands of influential people. Maybe it’s another genius marketing ploy (like the myth riddled protein Atkin’s diet)–people love to feel good about their personal yet poor decision making–and diet is very personal. Check out researchers that actually meant to study nutrition–like Dr. T. Colin Campbell’s The China Study comes to mind.

It was pretty apparent that the disease of non-critical thinking was at epidemic proportions.

After reading a number of these, I decided I had better take a look to see what Dr. Campbell had going on that had attracted such devotees.  I pulled up his book on Amazon and read through a few comments, most of which were even more nauseatingly gushing than the above.  I ordered a copy of The China Study.

I knew that both Anthony Colpo and Chris Masterjohn had done their own critiques of the original data, so I figured, what the hell, I’ll take a look at the ‘real’ China study (as opposed to the popular book of that name) and do one too.  And I’ll critique the popular book, which I figured was a rehash of the China project, while I’m at it.

I tracked down a copy of the 894 page book in a bookstore in the UK and forked over $240 to purchase it and have it shipped.  As I was awaiting its arrival I told Gary Taubes what I had done, and he replied that he had done the same thing himself a few years earlier.  And that I could have borrowed his.  And, even worse, that most of the data was available online for free.

When the book arrived, I was amazed at the size of it.  Not only was it the 894 pages as advertised, it was in a large format.  Much larger than a volume of the Enclyclopaedia Britannica.  It wasn’t at all what I thought it would be.

Here are a couple of photographs shamelessly using our own book to show the size of this behemoth

Of the 894 pages, the first 82 are a study overview, description of methodology and author commentary.  It is written in the form of a scientific paper with half the page in English and half in Chinese (which, presumably, is a translation of the English half).  The remainder of the 894 pages are raw data and correlations.  Page after page after page of correlations.  I didn’t bother counting them, but Dr. Campbell says there are 367 variables, each of which is compared with every other variable.  I don’t doubt him.  This study was a massive undertaking, requiring thousands upon thousands of man hours and God only knows how much money.  No one can possibly accuse the team members of not giving it their all.

Here is one page of correlations.  This one between stearic acid and all the other variables studied.

But in the end it is still only an observational study.  And even though – again, according to Dr. Campbell – there are over 8000 statistically significant correlations, correlations are not causation.  Any scientist worth his/her salt will tell you that all you can do with data from observational studies is use them to form hypotheses that can be rigorously tested in randomized, controlled trials.  Then and only then (assuming the study results show it) can you even begin to talk about causation. The whole enterprise, costly and time consuming though it was, was described perfectly by Shakespeare in the words of MacBeth:

…it is a tale
Told by an idiot, full of sound and fury,
Signifying nothing.

Once I saw that the original China study was nothing but a huge number of correlations, I quickly lost interest.  What is the point in going through the brain damage of ferreting around in these to see if Dr. Campbell interpreted them correctly when he tries to make his case that a plant-based diet is optimal.  It doesn’t really matter whether he interprets them correctly or not, they are only correlations.  Repeat after me one last time: Correlation is not causation, correlation is not causation, correlation is not causation…

I wondered why Dr. Campbell and his group didn’t spend a fraction of the time and money they spent on this behemoth of a spreadsheet full of correlations on a real study that could provide hard evidence.  Why not randomize subjects into two groups and provide one a plant-based diet and the other a meat-based diet or something similar.  Lock them down as Ancel Keys did if they had to.  Surely the money spent on the China study could’ve covered that.  Get some real data.  I discovered later that I wasn’t the only one who wondered that.  Even some of Dr. Campbell’s own colleagues abandoned him to this study and told him it would be worthless.  More about this later.

So enough for me.  I stuck my copy of the $240 book of correlations in my library and forgot about it.  Until Denise Minger’s critique hit the net.

Upon reading her blog post, my first reaction was This is great; someone took the time to do what I was going to do. I figured Dr. Campbell had cherry picked his correlations to  make the case he wanted to make, and I had seen Colpo and Masterjohn catch him on it.  Ms. Minger went even further and really caught Dr. Campbell with his pants down, correlation-misinterpretation speaking.  I continued to read with mounting glee Ms Minger’s successive critiques and a few other bloggers who had critiques of their own.  (Believe me, there is no dearth of material here for people to attack without any two attacking the same data twice.)

After this went on for a while, I had my second reaction to the whole affair.

Which was that I had fallen victim to the confirmation bias.  My bias was that Dr. Campbell was wrong, so I was more than happy to uncritically accept evidence confirming his error without lifting a finger to double check said evidence myself.  I knew that if a blogger somewhere had come out with a long post describing an analysis of the China study demonstrating the validity of all of Dr. Campbell’s notions of the superiority of the plant-based diet, I would’ve been all over it looking for analytical errors.  But since Ms. Minger’s work accorded with my own beliefs, my confirmation bias ensured that I accepted it at face value.

Once the fact that I had succumbed to my confirmation bias settled in around me, I became suffused with angst.  I had tweeted and retweeted Ms. Minger’s analysis a number of times, giving the impression that I had at least minimally checked it out and had approved it.  I had emailed it to a number of people, many of whom, I’m sure, had forwarded it on.  I’m sure I played a fairly large role in the rapid dissemination of the anti Campbell/China study info.

(It didn’t really make me feel better to know I wasn’t alone in falling into the confirmation bias quicksand.  Take a look at this post from Richard Nikoley’s Free the Animal blog.  I doubt that all these people checked Ms. Minger’s calculations before posting.)

My angst wasn’t because I had possibly fed the flames of a misinformation wildfire – I wasn’t particularly worried about that because mountains of other data (including first hand data from my own clinical practice) have persuaded me that Dr. Campbell is dead wrong in his ideas about the superiority of a plant-based diet.  No, my angst arose for two other reasons: first, because I was distressed that I so easily fell prey to the confirmation bias, and, second, because I felt I needed to go through all the calculations  myself to make sure Ms. Minger and others whose work I had circulated were truly correct in their analyses.

As I was wallowing in self pity over all this, I didn’t realize that salvation was at hand. And that my savior was none other than Dr. T. Colin Campbell himself.

Yep, his first response to Denise Minger’s critique of his work appeared on the Tynan.net website and rescued me from my pit of self-loathing.  In it, Dr. Campbell wrote:

But she suffers one major flaw that seeps into her entire analysis by focusing on the selection of univariate correlations to make her arguments (univariate correlations in a study like this means, for example, comparing 2 variables–like dietary fat and breast cancer–within a very large database where there will undoubtedly be many factors that could incorrectly negate or enhance a possible correlation). She acknowledges this problem in several places but still turns around and displays data sets of univariate correlations.

In other words, the China study is an observational study comparing one variable to another (univariate correlations) and, as such, meaningless.  And this from the man’s own pen.

Since these observational studies are meaningless in terms of causality, it doesn’t really matter how one slices and dices the data because meaningless correlations by any other names are still just as meaningless.  All this falderal over whether or not Dr. Campbell had his interpretations right was tantamount to the medieval theological argument over how many angels could stand on the head of a pin.  And my participation certainly wasn’t required.

I’d known this all before, of course, but somehow had lost my focus on it.

I was ready to wash my hands of the whole affair when I came across another statement Dr. Campbell made in his response to Ms. Minger’s critique.  Writing of her, he said:

One further flaw…is her assumption that it was the China project itself, almost standing alone, that determined my conclusions for the book (it was only one chapter!). She, and others like her, ignore much of the rest of the book.

Only one chapter? As I mentioned above, I always figured The China Study was simply Dr. Campbell’s tale of the China study and the conclusions he had drawn from it.  Now he says that only one chapter is about the China study, leaving me to conclude that the rest must be about something else.  I found the book, which I hadn’t yet taken from the pack it came in from Amazon, opened it and started reading.

Wow!

In 1976 author Mary McCarthy famously said live on the Dick Cavett show of her rival Lillian Hellman:

Every word she writes is a lie, including ‘and’ and ‘the’.**

I feel much the same way about The China Study.  Except it’s not really a lie, it’s an obfuscation.

In fact, in my studied opinion, The China Study is a masterpiece of obfuscation.

It is obfuscatory in so many ways it could truly qualify as a work of obfuscatory genius. It would be difficult for a mere mortal to pen so much confusion, ambiguity, distortion and misunderstanding in what is basically a book-length argument for a personal opinion masquerading as hard science.

Let me take just one tiny section of the book, one that is in no way atypical, and show you what I mean.

In Chapter 3 titled Turning Off Cancer, Dr. Campbell is starting to hit his stride in his anti animal protein jihad.  He has described the three stages of cancer – initiation, promotion and progression – and is setting the stage for his description of his laboratory work implicating animal protein in all three stages.

Here is his setup paragraph starting on page 50:

At the start of our research, the stages of cancer formation were known only in vague outline.  But we knew enough about these stages of cancer to be able to structure our research more intelligently.  We had no shortage of questions. Could we confirm the findings from India that a low-protein diet represses tumor formation?  More importantly, why does protein affect the cancer process?  What are the mechanisms; that is, how does protein work?  With plenty of questions to be answered, we went about our experimental studies meticulously and in depth in order to obtain results that would withstand the harshest of scrutiny.

The “findings from India that a low-protein diet represses tumor formation” were the results of a rodent study published in the Archives of Pathology in 1968 that Dr. Campbell wrote about 14 pages earlier in the book.  He mysteriously refers to the Archives of Pathology as an obscure journal when it is anything but.  It was published then by the American Medical Association and still is today under the new name Archives of Pathology & Laboratory Medicine.  But the notion of the paper initiating his quest being discovered by Dr. Campbell in an “obscure medical journal” fosters the impression of him as a leave-no-stone-unturned kind of guy.  Even the little throw away but incorrect phrase “obscure medical journal” is part of the greater picture of obfuscation that maintains throughout the book.

The study from India showed that rats given aflatoxin along with a high-protein diet got liver cancer while rats given the same amount of aflatoxin while consuming a low-protein diet didn’t.  Aflatoxin is a substance released from a fungus often found in peanuts, corn, other grains and even hay. It is converted in the liver to a much more toxic compound and is often used in laboratory experiments with animals to induce cancer and other problems.

Moving on, here is what Dr. Campbell has to say about protein and cancer initiation:

[I] How does protein intake affect cancer initiation?  Our first test was to see whether protein intake affected the enzyme principally responsible for aflatoxin metabolism, the mixed function oxidase (MFO).  This enzyme is very complex because it also metabolizes pharmaceuticals and other chemicals, friend or foe to the body.  Paradoxically this enzyme both detoxifies and activates aflatoxin.  It is an extraordinary transformation substance.

[II] At the time we started our research, we hypothesized that the protein we consume alters tumor growth by changing how aflatoxin is detoxified by enzymes present in the liver.

[III] We initially determined whether the amount of protein that we eat could change this enzyme activity.  After a series of experiments, the answer was clear (Chart 3.2).  Enzyme activity could be easily modified simply be changing the level of protein intake.

[IV] Decreasing protein intake like that done in the original research in India (20% to 5%) not only greatly decreased enzyme activity, but did so very quickly.  What does this mean?  Decreasing enzyme activity via low-protein diets implied that less aflatoxin was being transformed into the dangerous aflatoxin metabolite that had the potential to bind and to mutate DNA.

These four little paragraphs and accompanying chart take up less than a page in space, and are tiny glittering gems of obfuscation.  Let’s deconstruct.

First, take a look at how subtly these four paragraphs are written, especially II.  Note how he writes “the protein we consume”?  I’m sure many people took these paragraphs to mean that the studies were done on humans.  That’s almost the implication.  Reread them to see if they indicate anywhere that the author is talking about rat studies.

As Dr. Campbell progresses through this chapter, he does ultimately tell the reader he is talking about rat studies and not human studies, but he doesn’t mention the word rat for another two pages after the above paragraphs. By this time it’s probably implanted in the minds of many readers that he’s talking about human studies.

He describes experiments showing that rats getting diets high in casein (a milk/animal protein) develop more cancer at the same dose of aflatoxin than do rats getting a lower-casein diet.  The implication: animal protein causes cancer.

Dr. Campbell then gave his rats diets of varying amounts of plant protein (wheat gluten) and found that they did not get cancer after exposure to aflatoxin irrespective of protein dose.  Same thing happened with soy.  Implication: plant protein protects against cancer.

If you’re worried about cancer – and who isn’t – you’re now starting to look at animal protein a little differently.  Which is what Dr. Campbell wants.  But he hasn’t told you the complete story.

As I’ve written often in these pages, rodents aren’t just furry little humans.  They are a distinct species separate and apart from humans.  The rodents usually used in lab experiments are Sprague-Dawley rats, and inbred strain that has a tendency to develop cancer easily. (See Abelson, PH. (1992) Diet and Cancer in Humans and Rodents, Science 255(5041); Jan 10: 141)  In fact, these rats can develop cancer just from a change in diet.  I ran quick checks on a bunch of the studies referenced in The China Study, and all checked used Sprague-Dawley rats.

And think about this.  If you were to visit a farm and search for rodents, where do you think you would be most likely to find them?  In the grain or in the milking area?  Like Dr. Campbell, I grew up in a rural area and spent a lot of time on a farm.  Rats and mice are in the hay and in the grain.  You have a helluva time keeping them out of the animal feed, which they eat, too.  Grain and hay are common places for growth of the fungus that produces aflatoxin.  Since rodents spend most of their days in this stuff (grains), and since they eat it as well, I would bet that most have adapted over the generations to  the combination of plant protein and aflatoxin.  If this did them in regularly, there wouldn’t be the rodent problem on farms that there is.  So, in my opinion, making a huge issue of the fact that rats didn’t get cancer after dosing with aflatoxin irrespective of how much plant protein they ate is pretty disingenuous.

Most disingenuous of all in the above four paragraphs and chart is the lack of full disclosure in these paragraphs of the very study Chart 3.2 is made from. Let me explain.

Certain enzymes in the liver convert aflatoxin into a more toxic substance that Dr. Campbell claims can initiate the formation of cancer.  He demonstrates in rat studies that giving the rats a lower protein diet decreases the activity of this enzyme, meaning that the lower the protein intake, the less conversion of the aflatoxin into the really nasty stuff.  Chart 3.2 above and on page 52 of his book shows this graphically.

When I pulled the study from which this chart was adapted (Mgbodile MUK and Campbell TC. (1972) Effect of protein deprivation of male weanling rats on the kinetics of hepatic microsomal enzyme activity, J Nutr, 102: 53-60.) and read it, I found a little disclaimer Dr. Campbell didn’t bother to mention in The China Study.  You can read the last paragraph of the study (highlighted in yellow) below:

Nice, eh?  He hits the nail on the head.  Protein utilization may be influenced by what is eaten along with the protein.  Sucrose (table sugar) was eaten along with the protein used in this experiment.  In other experiments corn starch was used instead of sugar and the effect of the protein on the enzyme was diminished, meaning that the protein along with starch did not have nearly the same effect as protein with the sugar.  Who knows whether or not it’s even the protein that has the effect and not the sugar?  It can’t be shown from this study. That caveat certainly didn’t make in into The China Study.

See what I mean about a masterpiece of obfuscation?

I could go on and on, but I’ll quit after I give you just a couple more examples.

On page 107 of The China Study Dr. Campbell writes:

At the end of the day, the strength and consistency of the majority of the evidence is enough to draw valid conclusions.  Namely, whole plant-based foods are beneficial, and animal-based foods are not.

Then one inch below (literally) he writes the following:

The China Study was an important milestone in my thinking.  Standing alone, it does not prove that diet causes disease. [Italics in the original]

So, the China study produces valid conclusions as to causality, i.e., “whole plant-based foods are beneficial, and animal-based foods are not.”  Yet the China study “does not prove that diet causes disease.”  Say what?

Don’t believe me, take a look at a scan of my copy:

On page 73 Dr. Campbell dons the mantle of prestige conferred by one of America’s most august newspapers.  Writes he referring to the China study:

We had a study that was unmatched in terms of it’s comprehensiveness, quality and uniqueness.  We had what the New York Times termed “the Grand Prix of epidemiology.”

A quick search of that phrase in the online version of the NY Times reveals that it came from an opinion piece by none other than Jane Brody, a kindred spirit to Dr. Campbell.  Brody, a lipophobe of the deepest hue, has written a number of low-fat cookbooks and is a believer in the plant-based diet. So she hardly qualifies as an unbiased commenter.

And speaking of the so-called plant-based diet, when Dr. Campbell responded to Ms. Minger’s critique, he took her to task for mentioning the words ‘vegan’ and ‘vegetarian’ as it applied to his work.

One final note: she repeatedly uses the ‘V’ words (vegan, vegetarian) in a way that disingenuously suggests that this was my main motive. I am not aware that I used either of these words in the book, not once. I wanted to focus on the science, not on these ideologies.

Just for grins, I turned to the index of The China Study to see if ‘vegan’ or ‘vegetarian’ were indexed.  Here’s what I found on page 417:

vegetarianism or veganism. See plant-based diet

When I flipped over  to ‘plant-based diet’ on page 414, I found a long grocery list of references.

Even in his online response to his opponents, Dr. Campbell apparently can’t resist obfuscating.

Okay, just one more, then I’ve got to draw this to a close.  Let’s go back to the bottom of page 52, the page the paragraphs above and Chart 3.2 appear on.  Dr. Campbell shows in Chart 3.2 how protein is involved in stimulating the liver to convert aflatoxin to the toxic product that he implies is involved in cancer initiation.  He then reports how he wanted to see if animal-based protein was involved in the other phases of the cancer progression cascade.  So he and his grad students started to look.  He writes:

As time passed, we were to learn something quite remarkable. Almost every time we searched for a way, or mechanism, by which protein works to produce its effects [on cancer formation and progression], we found one!

That, my friends, is almost the dictionary definition of the confirmation bias summed up in one sentence.

This tiny bit of the book that I’ve chosen to lay bare is truly the tip of the iceberg.  I could go on and on and on, but I’m sure you get the picture.

Before I finish, I want to get back to something I mentioned earlier about how one of Dr. Campbell’s own colleagues bailed out from the China study because he recognized it for what it was: a giant observational study that was meaningless.  Here is how Dr. Campbell describes it on page 105-106:

When we first started this project we encountered significant resistance from some people.  One of my colleagues at Cornell, who had been involved in the early planning of the China Study, got quite heated in one of our meetings.  I had put forth the idea of investigating how lots of dietary factors, some known but many unknown, work together to cause disease.  Thus we had to measure lots of factors, regardless of whether or not they were justified by prior research.  If that was what we intended to do, he said he wanted nothing to do with such a “shotgun” approach. [i.e., a big, meaningless observational study]

This colleague was expressing a view that was more in line with mainstream scientific thought than with my idea [i.e., a randomized, controlled trial that might demonstrate causality would be a better use of the funds.] He and like-minded colleagues think that science is best done when investigating single – mostly known – factors in isolation. [He and like-minded colleagues are correct.] An array of largely unspecified factors doesn’t show anything, they say. [They are right.] It’s okay to measure the specific effect of, say, selenium on breast cancer, but it’s not okay to measure multiple nutritional conditions in the same study, in the hope of identifying important dietary patterns.

I prefer the broader picture, for we are investigating the incredible complexities and subtleties of nature itself…

So I say we need more, not less, of the “shotgun approach.” We need more thought about overall dietary patterns and whole foods.  Does this mean that I think the shotgun approach is the only way to do research?  Of course not.  Do I think that the China Study findings constitute absolute scientific proof?  Of course not.  Does it provide enough information to inform some practical decision-making? [No.] Absolutely.

Dr. Campbell uses an impassioned written speech to persuade the scientifically untrained that the China study carries vastly more scientific value than it actually does. Once again, it’s a large observational study, but an observational study nonetheless.  And as such, it is useful only in developing hypotheses to be tested with randomized, controlled trials.  The entire 894 page study proves not a shred of causality.

What saddens me about all this is that hundreds of thousands (probably millions) of people who can’t (or won’t) read critically have fallen for the premise of The China Study without even thinking about it.  Believing that the entire book is based on the greatest and most important nutritional study ever completed.  What happened to the ability to read critically?  Has it vanished from the populace?  Based on the comments on The China Study on Amazon it would seem so.

In my opinion, there really isn’t much of substance in the entire 400 plus page book.  But I encourage you to buy it and read it to test your own critical reading skills.  If you don’t want to test your critical reading skills, you’ll at least enjoy coming across some real howlers such as this one believed only by the vegetarian/vegan zealots out there (oh, sorry, plant-based diet followers):

As you will see in this book, there is a mountain of scientific evidence to show that the healthiest diet you can possibly consume is a high-carbohydrate diet. [italics in the original]

I wonder if Gary Taubes, who wrote a vastly more scientific book, would agree?

Lest you think I’m being too hard on poor Dr. Campbell, let me tell you a few things.  First, as I mentioned earlier, the few sections of The China Study I dissected are just a tiny fraction of the whole.  I could go on and on. Second, Dr. Campbell mentions Protein Power by name on page 19 and labels it a modern protein fad diet that “continue[s] to inflict a great variety of dangerous health disorders.”  Third, he is absolutely and unnecessarily brutal in his treatment of Dr. Robert Atkins.  He has an entire section on Dr. Atkins starting on page 95 that runs for almost three pages.  After quoting from one of Dr. Atkins’ books, he writes the following about the deceased diet doctor:

There are snake oil salesman, who have no professional research, professional training or professional publications in the field of nutrition, and there are scientists, who have formal training, have conducted research and have reported on their findings in professional forums. Perhaps it is a testament to the poser of modern marketing savvy that an obese man with heart disease and high blood pressure [here he inserts a citation for an article discussing Dr. Atkins’ death] became one of the richest snake oil salesmen ever to live, selling a diet that promises to help you lose weight, to keep your heart healthy and to normalize your blood pressure.

A way below-the-belt commentary when you consider that Dr.Atkins was a trained cardiologist who took care of thousands of real, live patients throughout his career – he wasn’t, like Dr. Campbell, a bench scientist doing rat studies in a lab.  Bob Atkins and I have had our differences, but were he still alive, I would vastly prefer to put my own care in his hands than I would those of Dr. Campbell, who has never treated a patient in his life.

You may ask if I took anything of value from my reading of this book?  I did.  On page 107 Dr. Campbell writes the following:

The results of this study…convinced me to turn my dietary lifestyle around. I stopped eating meat fifteen years ago, and I stopped eating almost all animal-based foods, including dairy, within the past six to eight years, except on very rare occasions,  MY cholesterol has dropped, even as I’ve aged; I am more physically fit now than when I was twenty-five; and I am forty-five pounds lighter now than  was when I was thirty years old.  I am now at an ideal weight for my height.

I have no reason to doubt Dr. Campbell’s own medical and dietary history (except maybe for the part about being more physically fit than he was at age 25 – that’s a tough act for someone who is 73), so I’ll assume it’s all true.  As I recall, he had a trim physique when I met him 10 years ago, which, assuming nothing has changed, is probably the same.  And I’m going to take Dr. Campbell at his word about what he eats.

Granted, I’m younger than Dr. Campbell, but I follow almost the opposite diet as he does yet I, too, have low cholesterol, very low blood pressure and am ideal weight for my height.  What this all tells me is how wonderfully adaptive the human species is where diet is concerned.  It’s no wonder we took over the earth.

** Lillian Hellmann was predictably furious over McCarthy’s comment and adopted the typical American response: she sued.  In one of those turns in which the law of unintended consequences jumps up and bites one, many of her untruths came to light in the courtroom as McCarthy was forced to defend her statement.  Hellmann disengaged by dying during the proceedings.

As anyone who regularly reads this blog can tell, I’ve been a bit hit and miss in posting lately.  The bride and I have been swamped with work on the Sous Vide Supreme project.  MD has been working with chefs to develop recipes along with creating a bunch herself; she has been editing a book on sous vide for the home cook written by yet another sous vide expert; she’s been posting on the Sous Vide Supreme blog (eggs the sous vide way); and, as you can see at the left, she’s been talking sous vide to anyone who will listen.  All this while she prepares for performing the Messiah in about two weeks.  I’ve been heavily involved in the business end of things, which is a never-ending task.  Plus, I’m the taster-in-chief.  Neither of us dreamed that this would turn into such a time-gobbling project after the development of the machine.  But it has.  It seems that we are spending twice as much time now working in some capacity on  Sous Vide Supreme than we ever did before – even when we were at our busiest.  I’m going to have to work harder on my time management if I expect to keep up with all the other projects – including this blog – that I have going.

Twitter

The sous vide time commitments have put a real hickey on my reading.  I’ve probably read less over the past four months than in any four month period of my life.  Instead of five or six books per week, I’m down to about two or three max.  I hate it.  I’m trying to keep up with my daily medical/scientific journal trawl, but that has even slacked off a bit.  When I do find something of interest, instead of blogging on it as I used to, I stick it up on my Twitter page.  I probably post 10-15 times per day on Twitter, so if you want to keep up on a moment-by-moment basis, follow me on Twitter.  If you have a problem thinking of yourself as a Twitter person, give it a try.  I dipped my toes in the Twitter waters with great hesitation, and now I love it.  I’ve found it extremely valuable because I find all kinds of new stuff daily.  You’ve got to be careful who you follow, however, or you can waste a ton of time.  If you get started, start following people who provide you with information you can use.  I avoid following people who do nothing but tell me what they ate for breakfast that day or what movie they’re going to see that night.  Sign up an give it a go. You don’t have to write anything (or tweet, as it’s called) if you don’t want to.  You can simply lurk and be the beneficiary of a ton of good info.   The Twitter people take you by the hand and get you squared away.  It takes all of about two minutes – if even that.  Literally.

Comments

I have fallen way, way behind on dealing with comments.  As I wrote a while back, I had to stop answering individual comments, and I’ve pretty much stuck to my guns on that.  Problem is, I had about three hundred comments stacked up before I started doing that.

When comments come in and I post them, they go up in by date.  So back when I was spending half my day dealing with them, I would often come across a comment that required some thought and a detailed answer.  If I didn’t have time to deal with it right then, I put it off until later.  Often when later came, I had 20 or 30 more that came in after the one requiring the time.  I didn’t want to answer those and put them up ahead of the one I hadn’t answered, so I simply didn’t deal with any of them.  Now I’ve got about 340 of them stacked up and it gives me heartburn whenever I even get on my blog administration screen.  The sad thing is that some of these comments go back months and months.

I’ve been wracking my brain trying to figure out what to do with them, and I’ve finally come to a decision.  I’m simply going to post them as they are.  I’m going to post about 30 of them per day until they’re all up.  Why not all at once?  Because I know many of you are set up to get comments emailed to you when I post them.  I don’t want to clot email accounts with 340 emailed comments all at once, especially since some of these comments are lengthy.  So, I dole them out over the next 10 days or so while keeping up with the new comments as they come in. I won’t start this process for a few days to get those of you who don’t want even 30 of them a day coming in to unsubscribe.

Since many of these hoarded comments contain very good questions, they are a trove of subjects for future blog posts.  As I post them, I’m going to reread them and clip those that would make for good posts into Evernote or my new favorite plaything DEVONthink that I’m just starting to feel my way along with. (See this great Steven Johnson (whom I follow on Twitter) article about the virtues of DEVONthink.)  After I’ve got these blogworthy comments in a format in which I can find them instantly, I’ll start working through them and posting.

Bloggers and the Federal Trade Commission (FTC)

I don’t know how closely blog readers attended to the recent announcement by the FTC that they were going to start riding herd on bloggers, but the bloggers went ballistic.

Among its other duties, the FTC patrols the universe of advertising in this country looking for anyone or any company engaging in, as they term it, deceptive practices.  In other words, the FTC is on the prowl seeking out advertisers who make false claims in order to stop them and punish them.  Which all sounds good in the abstract, but in reality is a whole other story.

As I pointed out in an earlier blog, it’s a valuable exercise to read Kevin Trudeau’s first book to see how the FTC operates.  The nutritional and health information he presents is total garbage, but his description of the practices of the FTC is right on the money. (I’ve got to admit that some of the nutritional and health information presented in Trudeau’s first book (the only one I’ve read) is accurate, but I write that off to the law of averages.  He presents so much information that odds are some of it just happens to be true.  So, if you read the book and come across something that is nutritionally accurate, don’t write me about it.  I know a few things are there, but not enough to justify reading the book other than the first part, which is an excellent treatise on the FTC.)

The FTC has the power to absolutely ruin anyone and/or any company it chooses to go after.  If you read the first part of Trudeau’s book, you’ll see how.

So, the FTC opined that they planned on monitoring bloggers to see if they disclosed the fact that they were paid to do reviews on products.  Apparently, many bloggers make money by doing paid reviews on products without disclosing such, and the FTC doesn’t like it.

I’ve never reviewed products for pay, but I have read enough about it to know how it works.  Companies provide bloggers products, then pay these bloggers for reviews of the products.  I guess the fact that bloggers are given the products and possibly paid for the reviews as well might induce them to write positive reviews of products that they thought sucked.  And I assume that’s what the FTC is concerned about.

The FTC’s actions certainly got the blogosphere in an uproar.  So much so, in fact, that the FTC started to crawdad, which I never thought would happen.  Just goes to show that if you turn the spotlight of public awareness on even the most aggressive and powerful of all government agencies, you can get results.

Not that I fear the FTC on this (at least not at this point), I’ll go ahead and disclose where I get dinero from this blog.  Virtually all of the money that comes to me through the blog comes from readers buying products through Amazon.com.  When they buy a book I recommend or go through one of the book thumbnails of Protein Power or the 6-Week Cure up at the top right or any of our other books I have up on the site, I get a little bit of lucre for it.  And I get a little more if they buy anything else after entering Amazon through one of the portals in this blog.  In a good month, it’s enough to cover my hosting and web guy expenses; in a bad month (as this one is turning out to be), it’s about enough to cover the hosting of the site and maybe an hour or so of the web guy time.

Google ads

I get a little income from Google ads, but I’m trying to get them off the site.  I’ve had several web guys working on the site over the years, and I guess code for these Google ads is stuck all over the place.  I get rid of them in once place, it seems they pop up somewhere else.  When I had Google ads everywhere, I made about $150 per month, which, in my opinion, isn’t enough to justify tacky-ing up the site with a zillion ads.  Plus, I don’t have time to go through and spend time trying to figure out which ads to block.  Many people, I’ve learned, don’t realize that these ads aren’t part of the site, and they wonder why, when I’ve just spent 2000 words bashing statins, an ad for a statin pops up.

A while back I was having lunch with Mark Sisson of Mark’s Daily Apple when he asked me what kind of a deal I had going with Atkins Nutritionals.  I told him I didn’t have any kind of deal going with them whatsoever.  I asked him why he asked.  He told me that he gets my blog posts by email, and that at the bottom of each one is a banner ad from Atkins.  I was embarrassed to say that I didn’t even know you could get the posts by email and that I didn’t have a clue why the Atkins ads were there.  I went home and pulled up the blog (I usually never look at the actual blog – only the admin page), and sure enough, there was a way I could get the posts by email.  I signed up to get my own posts, wrote one, and sure enough, here it came with an Atkins ad at the bottom of it.  I thought I had it all taken care of, but I just looked moments ago and there is still a banner ad at the bottom of the emailed post.  I’ve added it once more to the list of things to have my guy deal with when I get with him on Monday.

Book recommendation

While on the subject of Amazon.com, books and book recommendations, I might as well recommend one.
I finished a terrific book not long ago called A Colossal Failure of Common Sense: The Inside Story of the Collapse of Lehman Brothers. As the title implies, this is a treatise about the fall of the House of Lehman, one of the country’s oldest investment banks, and is written by one of the vice presidents who names names and points the finger.

Not only is this book chock full of great information about how Lehman Bros, Bear Stearns, Goldman Sachs and others operate, it is extremely well written.  The ‘author’ realized he didn’t have the skills to tell his own story in a readable manner, so he hired a writer.  But he didn’t just go out and hire one of the non-fiction write-for-hire folks that are swarming around out there, he hired Patrick Robinson, a best-selling thriller writer.  As a consequence, the book is absolutely gripping. Not only do you learn a ton about how the financial crisis developed, you learn it in a gripping, racing-through-the-pages fashion.  You’ve heard people say about certain books that they read like a novel.  Well, this one does.  I had real trouble putting it down.

After reading this book, you will know exactly why we’re in the boat we’re in now and will be stupified at the mismanagement at the top.  As I read through and learned about the perfidy of Moody’s, Standard & Poors, and the other financial rating outfits that gave the most worthless financial instruments triple A ratings, I was stunned that these companies hadn’t been prosecuted.  Without their complicity, the whole house of cards couldn’t have been erected because no one would have purchased the products.  I was interested to read in today’s Financial Times that at least  Ohio is going after them.  I suspect Ohio won’t be the last.  According to the author, these companies made billions while failing to do their due diligence before passing out AAA ratings like they were candy at Halloween.

Not long after I read the book, I came upon a piece by Calvin Trillin in the editorial section of the New York Times that summed up the situation nicely.  The problem was the enormity of the amounts of money waiting to be made drew smart people to Wall Street.  A funny but insightful short essay.

After you read the book and Trillin’s piece, take a look at this video I posted about a year ago.  It will make it all that much more funny.  And sad.

The 6-Week Cure blog

All I can say is that it’s about up.  And apologies for not having it up sooner.  I hope we’ll have it operational this week and populated with a few posts.

Another vegetarian myth

I wrote in a bookish post (or maybe in answer to a comment on a bookish post – I can’t remember) a while back that I had read most of the mystery novels out there and was looking for a new series to sink my teeth into.  Someone suggested the DI Charlie Priest mysteries by Stuart Pawson.  I got one and liked it, so I’ve been motoring through those as time allows.

The last one I read was Deadly Friends about a murdered doctor, a serial rapist and a host of other minor villains. At a point about midway through, DI Priest and one of his underlings are walking around scoping out a pharmacy prior to entering to get info about the dead doctor.  All these books – at least the four or five I’ve read so far – are written in the first person, so everything is from Priest’s perspective.  Here’s what he says:

We completed our circuit of the block.  Passing the back of the butcher’s I tried not to inhale and wished I had the willpower to go vegetarian.  Trouble is, I like my steaks.

AAARRRGGGHHHH!  Even in mystery novels I’m being reminded of how deep the vegetarian mantra has wormed its way into our collective brains.  How many times have we all heard variations on this theme?  One of the ideas the vegetarian movement has managed to get firmly implanted in the minds of many is that vegetarianism is a more healthful way to eat.  I’ve heard numerous people wistfully say they really would like to be able to follow a vegetarian diet because it’s so much more healthful, but they just like meat too much to do it.

The truth is, as we all know, that vegetarian diets are decidedly less healthful than diets containing animal protein. But the great unwashed masses don’t seem to have figured this out.

But I’ve got to hand it to the vegetarian brigade: they’ve managed to successfully propagandize most of the population.  And they’ve done so without any real science behind them.  The most they can point to is a sheaf of observational studies that don’t prove squat.

The low-carb/Paleo movement, on the other hand, is producing more data almost daily that a lower-carb, higher-fat, higher-protein diet is infinitely better for a majority of the population.  But, we don’t get the message out as well as the other side does, I suppose.  I went to a Borders Books the other day and found an entire collection of free booklets written for children telling of the horrors of factory farming and encouraging them to go vegetarian.

We are starting to make some inroads into this nonsense, however, with the help of some former vegetarians who have seen the error of their ways.  If you haven’t read Lierre Kieth’s book yet, add it to your Christmas list.

I’m girding my loins for all the hostile comments I’m sure to get from angry vegetarians.  These comments will be from vegans telling me how healthy they are and how many miles they can run and how they could kick my butt in any endeavor I might wish to engage them in.  And they’ll reference the idiotic China Study and a host of other meaningless observational junk.  But wait.  I don’t have to gird my loins.  I’m not dealing with these comments any more.  I’m just posting them as they come in.  Give it your best shot.

To see under what conditions our genome developed, read on.

The hunter-gatherer lifestyle

Just to wrap this long, meandering post up, I want to end with a link to a great article in the December 2009 National Geographic.  And to bring this post full circle, I’ve got to let you know that I found this article on Twitter.  I wouldn’t have discovered it otherwise. At least not as quickly as I did.

The long article is about the Hadza who follow a hunter-gatherer lifestyle in remote Tanzania.  The area the Hadza roam is being encroached upon by all kinds of agricultural and tourist businesses, and the author doubts these indigenous people can maintain their lifestyle for much longer.
The men hunt and the women gather.  The Hadza went on a nighttime baboon hunt and took the author along.  His account of the hunt makes for a riveting read.  Once killed, the Hadza haul the baboon back to what serves as a camp and prepare to serve it up.  I’ll leave you with the author’s description of the meal.

Ngaola skins the baboon and stakes out the pelt with sharpened twigs. The skin will be dry in a few days and will make a fine sleeping mat. A couple of men butcher the animal, and cuts of meat are distributed. Onwas, as camp elder, is handed the greatest delicacy: the head.

The Hadza cooking style is simple—the meat is placed directly on the fire. No grill, no pan. Hadza mealtime is not an occasion for politeness. Personal space is generally not recognized; no matter how packed it is around a fire, there’s always room for one more, even if you end up on someone’s lap. Once a cut of meat has finished cooking, anyone can grab a bite.

And I mean grab. When the meat is ready, knives are unsheathed and the frenzy begins. There is grasping and slicing and chewing and pulling. The idea is to tug at a hunk of meat with your teeth, then use your knife to slice away your share. Elbowing and shoving is standard behavior. Bones are smashed with rocks and the marrow sucked out. Grease is rubbed on the skin as a sort of moisturizer. No one speaks a word, but the smacking of lips and gnashing of teeth is almost comically loud.

I’m ravenous, so I dive into the scrum and snatch up some meat. Baboon steak, I have to say, isn’t terrible—a touch gamy, but it’s been a few days since I’ve eaten protein, and I can feel my body perking up with every bite. Pure fat, rather than meat, is what the Hadza crave, though most coveted are the baboon’s paw pads. I snag a bit of one and pop it in my mouth, but it’s like trying to swallow a pencil eraser. When I spit the gob of paw pad out, a young boy instantly picks it up and swallows it.

Onwas, with the baboon’s head, is comfortably above the fray. He sits cross-legged at his fire and eats the cheeks, the eyeballs, the neck meat, and the forehead skin, using the soles of his sandals as a cutting board. He gnaws the skull clean to the bone, then plunges it into the fire and calls me and the hunters over for a smoke.

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 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 the journal was reluctant to publish the paper because the editors 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 was 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

One of the problems – if it could be called a problem – in writing this blog and moderating the comments is most readers are pretty intelligent. Occasionally I have the angry vegetarian wander in, take me to task for my errant ways, and, after a comeback or two on my part, drift away to never be heard from again.  Thanks to the confirmation bias, this blog pretty much selects against the non-meat eater.  So, I tend to forget how many people there are out there who are pretty much clueless about basic nutrition, and how many people there are who bobble through life spouting cliches they’ve heard along the way as great nutritional truths.  Based on the comments I get on this blog, it seems to me that most people are pretty nutritionally sophisticated and reasonable.

But I have just recently been disabused of that notion.

My friend Tim Ferriss put up an excerpt of our new book The 6-Week Cure on his site a few days ago and asked me if I would mind answering a few of the commenters.  I told him I wouldn’t mind at all, but I didn’t realize what I was getting myself into.

Tim’s blog isn’t really a nutritional blog – it’s a lifestyle design blog (said term invented by Tim himself).  There is a little nutrition thrown in here and there, but mainly the blog is focused in other directions.  As a consequence, it attracts mainly youngish readers who enjoy following Tim’s adventures and want to learn how to model their lifestyles after his.  My blog is specifically directed to folks more interested in nutrition who are willing to put up with my digressions into other areas from time to time, so I expect them to be more nutritionally aware.

I wasn’t prepared for what I got in the comments on Tim’s post.  Surprisingly, there were a fair number of commenters – maybe even a majority – who would feel right at home on my blog.  But there were also a fair number who made me realize that nutritional sophistication is far from a universal phenomenon.  You can take a trip over to the comments section of his blog to see what I mean.  I pretty much answered only those who I thought were totally off track, so you’ll be able to read my comments, then track back to the comment I was responding to and see what I mean.

The experience made me realize just how much of a void there is in good info out there explaining why humans really are meat eaters at heart, so I’ve decided to do a couple of posts on the subject to be able to refer to in the future when this issue arises.  While I was mulling this idea over, I received a link to a piece of sheer idiocy that really pushed me over the edge.  It made me realize that if this kind of stuff is out there circulating, it’s no wonder these people have such bizarre notions of what constitutes a rational diet.

I’m going to start off this first part by examining some of this nonsense, and I’ll finish off in the second part by going through one of the classic papers of all time showing why we humans aren’t just meat eaters, but we are humans because we eat meat.

The link I had sent by a friend of mine is one I’ve seen referred to on a couple of other low-carb or Paleo sites.  I didn’t give it much thought until the Tim Ferriss blog experience (which, BTW, is still going on.  I just got binged on my email that Tim approved another 15 or so comments that I need to take a look at, so keep checking his blog) made me realize that there were really people out their buying into this nonsense.

The piece from AlterNet starts out with a big, bold headline:

Eating Meat Is Not Natural

No equivocating there.  A categorical statement if I’ve ever seen one.  Let’s see how the author of the piece – Kathy Freston – backs it up.  She starts out with a short introductory paragraph that ends with another categorical statement.  I’ve noticed that these folks love to write these things with such authority.  Same with the people on Tim’s blog.  There is no doubt in their minds that they’re correct.  But they are operating in an informational void.

Which brings to mind a great quote from Lierre Kieth’s book:

I was on the side of righteousness, and like any fundamentalist, I could only stay there by avoiding information.

Here is the intro paragraph to the AlterNet piece:

Going through the reader feedback on some of my recent articles, I noticed the frequently stated notion that eating meat was an essential step in human evolution. While this notion may comfort the meat industry, it’s simply not true, scientifically. [My italics]

No hesitance there.  “It’s simply not true, scientifically.”  Not even a smidgen of doubt.

How does our author prove it’s not true?  By referring to the writings of people who present themselves as scientists but who are ideological vegetarians.

Dr. T. Colin Campbell, professor emeritus at Cornell University and author of The China Study (please check out the link), explains that in fact, we only recently (historically speaking) began eating meat, and that the inclusion of meat in our diet came well after we became who we are today. He explains that “the birth of agriculture only started about 10,000 years ago at a time when it became considerably more convenient to herd animals. This is not nearly as long as the time [that] fashioned our basic biochemical functionality (at least tens of millions of years) and which functionality depends on the nutrient composition of plant-based foods.”

Ah, our old friend Dr. T. Colin Campbell and the China study.  Many commenters on Tim’s blog referenced this study as if were gospel.  Before we get into The China Study, I’ve got a disclosure to make.  I’ve never read the thing.  So how can I talk about it intelligently?  Because I have appeared on the podium with Dr. Campbell.  A few years ago we both spoke at a symposium somewhere (I can’t even remember where now), and his talk preceded mine.  As I sat on the stage, I listened intently and made notes as I watched his slides.  What I realized right off the bat is that his whole shtick is nothing but an epidemiologic or observational study, which, as I’ve written about in these pages  before, proves no causality and serves only to derive hypotheses.  He spent his entire presentation trying to prove his thesis with studies that can’t he used to prove diddly.  Since I spent an hour listening, watching and then rebutting, I figure I’ve earned a pass from reading the book.

If you want to read more on The China Study, I suggest you take a look at two sources.  First, read Chris Masterjohn’s review, then you can read Dr. Campbell’s rebuttal, then Chris’s response to that.  And you can read my good friend Anthony Colpo’s review of the book.  The China Study is a pretty sorry piece of work and, since it is an observational study (the results of which are misrepresented in the pop science book available), it doesn’t prove squat.  I certainly wouldn’t rush out and become a vegetarian because of it.  Yet if you read some of the comments on Amazon, you would think this book is the Second Coming.  These poor people who have been so gulled simply don’t realize how worthless such studies are.

In the quote above, Dr. Campbell is obviously unaware that the birth of agriculture involved primarily the turn from a hunting/gathering subsistence to the growing of grain.  The agricultural revolution wasn’t a change from a herbivore existence to the herding of animals for food.  This kind of clap trap shows just how misguided these kind of folks are and how they twist the historical facts to suit their purposes.

[Note: I have since read The China Study and have posted about it here.]

The next ‘authority’ trotted out by our author is none other than Dr. Neal Barnard, the president of the inappropriately named Physician’s Committee for Responsible Medicine and himself a vegetarian.

That jibes with what Physicians Committee for Responsible Medicine President Dr. Neal Barnard says in his book, The Power of Your Plate, in which he explains that “early humans had diets very much like other great apes, which is to say a largely plant-based diet, drawing on foods we can pick with our hands. Research suggests that meat-eating probably began by scavenging — eating the leftovers that carnivores had left behind. However, our bodies have never adapted to it. To this day, meat-eaters have a higher incidence of heart disease, cancer, diabetes, and other problems.”

This is the Dr. Barnhard of the much-ballyhooed (by him, at least) ‘study’ of the ill effects of low-carb diets that I rebutted a few years back.

He is correct in saying that the earliest of men probably begin to eat meat by scavenging.  The paleontological record seems to bear that out.  But the line about our bodies never adapting to it and the statement that meat-eaters have higher incidences of all the diseases mentioned is pure malarky.  If Dr. Barnhard were asked to come up with references for these statements, all he could possible produce would be a few observational studies, which, as we all know, don’t prove anything.  And for each one he could come up with, I could come up with just as many showing the opposite.

Now we get to the big gun: Richard Leakey.

There is no more authoritative source on anthropological issues than paleontologist Dr. Richard Leakey, who explains what anyone who has taken an introductory physiology course might have discerned intuitively — that humans are herbivores. Leakey notes that “[y]ou can’t tear flesh by hand, you can’t tear hide by hand … We wouldn’t have been able to deal with food source that required those large canines” (although we have teeth that are called “canines,” they bear little resemblance to the canines of carnivores).

Hmmm.  I wonder if Leakey has ever seen the canines of a gorilla?  They certainly have the appearance of the canines of a carnivore yet gorillas are pure vegetarians.  But let’s go on.

In fact, our hands are perfect for grabbing and picking fruits and vegetables. Similarly, like the intestines of other herbivores, ours are very long (carnivores have short intestines so they can quickly get rid of all that rotting flesh they eat).  We don’t have sharp claws to seize and hold down prey.  And most of us (hopefully) lack the instinct that would drive us to chase and then kill animals and devour their raw carcasses. Dr. Milton Mills builds on these points and offers dozens more in his essay, “A Comparative Anatomy of Eating.”

All this anatomical stuff is pure gibberish, yet many people not skilled in the art of critical thinking buy into it.  In part II of this post, I’ll address many of these anatomical issues, so we’ll leave it until then.  If you’re bored, you might want to take a look at the Comparative Anatomy of Eating, which is a not-very-successful attempt to push a square peg into a round hole.  Dr. Milton really has to stretch to get the anatomy to fit with his notions of what it is designed for.  I’ve seen so many variations on this theme – people showing minor anatomical differences to prove that humans are really herbivores – that I’ve lost count.

The author now turns to her last expert, a big time, mainstream doctor.

The point is this: Thousands of years ago when we were hunter-gatherers, we may have needed a bit of meat in our diets in times of scarcity, but we don’t need it now.  Says Dr. William C. Roberts, editor of the American Journal of Cardiology, “Although we think we are, and we act as if we are, human beings are not natural carnivores.  When we kill animals to eat them, they end up killing us, because their flesh, which contains cholesterol and saturated fat, was never intended for human beings, who are natural herbivores.”

This guy really goes off the rails.  He tells us that “when we kill animals to eat them, they end up killing us,…”  A strong statement that he has absolutely nothing but his own opinion to back it up with.  Then he really takes a leap.  These animals we kill to eat do us in “because their flesh, which contains cholesterol and saturated fat, was never intended for human beings, who are natural herbivores.”  Oh, really.  That cholesterol will do us in, eh?  Why is it that we have cholesterol ourselves and plants don’t?  Why is every cell in our bodies capable of making cholesterol?  Because we don’t need it?  The depth of his dumbth is unfathomable.  Realizing that this guy is the editor of a major cardiology journal lets you know really quickly why such journals publish such biased articles.

Our author goes on.

Sure, most of us are “behavioral omnivores” — that is, we eat meat, so that defines us as omnivorous. But our evolution and physiology are herbivorous, and ample science proves that when we choose to eat meat, that causes problems, from decreased energy and a need for more sleep up to increased risk for obesity, diabetes, heart disease, and cancer.

Here again with the meat causes obesity, diabetes, heart disease and cancer.  Instead of the “ample science” she claims, there is no proof whatsoever.  She uses an interesting expression: she describes us humans as “behavioral omnivores,” which I think is a good definition, but she’s using it incorrectly.  She means that we are really herbivores, but we’ve learned to become omnivores, therefore we are behavioral omnivores, not real omnivores.  I agree with her, but with a twist.  I think we are designed as carnivores and have adapted to an omnivore existence, so we are behavioral omnivores, just not the way she thinks we are.  Gorillas are behavioral vegetarians.  They have the GI tracts from teeth to the other end of carnivores – and they do fine being fed meat in zoos – but they culturally are vegetarians or behavioral vegetarians.

Old habits die hard, and it’s convenient for people who like to eat meat to think that there is evidence to support their belief that eating meat is “natural” or the cause of our evolution. For many years, I too, clung to the idea that meat and dairy were good for me; I realize now that I was probably comforted to have justification for my continued attachment to the traditions I grew up with.

But in fact top nutritional and anthropological scientists from the most reputable institutions imaginable say categorically that humans are natural herbivores, and that we will be healthier today if we stick with our herbivorous roots. It may be inconvenient, but it alas, it is the truth.

She ends by summarizing all the twaddle she presented earlier.  And she relies on what others say to ‘prove’ her points – all the top scientists at all the most reputable institutions – which is a dead give away that she hasn’t gone to any original sources herself and is simply relying on hearsay.  But, hey, she’s a journalist, not a scientist, so she’s got to rely on the scientists to tell her what’s going on, right?  To a point, but she should also check with some other “top scientists” from other “reputable institutions” to perhaps provide counter opinions.

It almost defies belief that people can be so gullible as to put any credence whatsoever in an article such as this one, yet, after dealing with Tim’s blog, it’s apparent that many do.

One journalist who doesn’t, however, is my friend Amy Alkon, better known as The Advice Goddess who writes a syndicated column that I never miss.  In her latest, published in the Orange County Register, she gives advice to a vegan who has come a cropper in a burgeoning email romance with a non-vegetarian.  As you read the request for advice from the vegan, you can see her innate sense of moral authority start to bleed through.  Amy’s advice is priceless. (It was Amy, in fact, who emailed me the link (after some zealot had sent it to her) to the article above that I’ve just spent three pages dissecting.)

While you’re at it, read her advice to the next seeker after the vegan.  My favorite line:

People say the best things in life – love, friendship, moonlight – are free, but so are the worst things: lymphoma, a really big overbite, and road kill.

How true, how true.

The next post is going to be free, and I hope it will fall into the good kind of free category.  We’ll go over a famous paper from the anthropological literature making a virtually watertight case that it was eating meat that made us human.