Ask Gary a question II
Storm coming in over Lake Tahoe. Taken this morning from my office window.
I’ve closed the comments on the last post. A hundred plus questions is probably enough.
I know the readers of this blog are a clever lot, so I suspect that a number of you will continue to post questions through this post. Go for it. I’ll put them up, but unless they are of outstanding merit, they probably won’t get answered.
Now Gary and I have to work on how we’re going to pull this off technically, i.e., whether to go back and try to answer the questions within each comment like I usually do. Or whether we’re going to do it in a separate post. Whatever the case, it’s going to take a few days.
A couple of comments. First, Gary is a science journalist, not a physician or a research scientist. He is one of the few science journalists out there who can really penetrate the scientific jargon and get to the essence of what particular research papers really mean. But, due to time limitations, he can’t read every paper on every arcane subject and come up with an intelligent take on it. He has limited his efforts on the history of how we got to where we are nutritionally, and he has learned the biochemistry and physiology of carbohydrates, insulin and fat storage. Those are the things he can comment on. I don’t expect him to spend a lot of time digging into arcane research on issues that don’t have a lot of bearing on those subjects. That wasn’t our deal. And, despite my requests for no personal questions, there were a few of the ‘I’ve got this or that problem and am unable to lose weight – what do you suggest?’ variety, which will be ignored.
Thanks for all your interest and the great response. Hang in there, and we’ll have the answers up as quickly as we can.
One thing that was striking to me about GCBC is that it primarily addresses the sedentary population or at best the “acquainted with the treadmill a few times a week” population (which makes sense, since that describes the majority of Americans and no doubt the majority of study populations drawn from the American public). However, I’m interested in whether Mr. Taubes came across any material more relevant to an athletic population while researching his book, particularly athletes in activities other than endurance sports (e.g. team sports, sprinters, etc.) — I think the studies discussing low-carb endurance performance have been pretty well covered in the blogosphere. If he had any educated analysis to share that would be great, but raw citations would also be awesome.
I’d also be curious about whether Mr. Taubes has any gut feelings (or informed opinions) on whether phenotype or activity pattern makes more of a difference to those people who feel and/or perform better on higher or lower carb macronutrient ratios.
In response to Byron and others:
Carbohydrates as a macronutrient had nothing to do with increased “brain power.” There isn’t any magical power that carbohydrates hold to turn us from brutes into geniuses.
Civilization occurred from Hunter-gatherer tribes because of sustained population explosion. Population explosion was generated by growable carbohydrates, ie agriculture. It led to a massive increase in consumable calories. Previously, as a hunter-gatherer, human population was extremely limited because of available calories. If they didn’t kill it or gather it, they didn’t eat it. Rather, they starved.
Hunter-gatherers were simple folk. They didn’t need technology or the “advances” of civilization because they had all they needed. It’s how humans evolved. It worked for us.
Contrast that with civilization – now that you have agriculture, you need technology and written language to construct and regulate irrigation, calendars and mathematics and astronomy to estimate crop harvest times, crop yields, etc. People don’t have to actually go out and kill animals anymore, because there is plenty of food. The civilized people were free to specialize into a role that was needed.
It was agriculture and the transformation of the human from hunter-gatherer to civilian that caused the rapid advance of technology and “brain power.”
One more comment on heart palpitations for people who combine low-carb eating with the consumption of alcoholic beverages.
It has been known for years that alcohol consumption temporarily prevents gluconeogenesis, e.g., the production of glucose by the liver. This process, is, of course, an especially important backup system for keeping blood sugar in normal ranges for people on a low carb diet. The low-carber is thus more likely to experience low blood sugar -> high adrenalin -> heart palpitations after consuming alcohol.
If calories are not the issue and carbohydrates, by virtue of their effect on hormonal tone are the main cause of obesity, would eating 1,000 calories more than your base metabolic rate of pure fat meat cause fat gain?
It’s been a long time since I have seriously studied human paleontology (grad classes about 25 years ago), but I’d like to add that it’s amazing how much can be determined regarding diet based on studying the dentition of human fossils.
The size, shape, and wear patterns of the teeth can show whether the diet of the specimen was primarily hard seeds and vegetable matter that needed to be ground up before being eaten, as opposed to different patterns that are evident in meat eaters.
It’s good to study modern-day hunter-gatherers and then try to extrapolate what early humans ate, but it’s the dentition that really tells the story.
What would cause a person with reactive hypoglycemia to progress on to type II diabetes even while doing extremely low-carb? Eating too much protein? Eating too often?
None of the things mentioned should cause the problem. I would suspect a problem with the beta cells themselves.
Stargazey,
May I suggest you read Jenny’s excellent Blood Sugar 101 site? She has a lot of info on the multiple causes of diabetes that have identified (and unidentified but suspected) and lumped into the catch-all term “Type II”.
Some folks don’t have type II at all, but later and slower developing forms of Type I and 1.5 DM. Often their doctors don’t even know the difference, especially primary care doctors who are not up to date and still using what they learned in medical school. There are different treatment protocols for some of these “not really II” types so it’s important to to have the underlying reason for the diabetes identified to get the right treatment.
www dot bloodsugar101 dot com (replace dot with . and remove the spaces)
Well this one is tad bit late but here goes:
Would Gary research in a future project the science behind cancer? The chapter in the book is interesting but I wonder what he can achieve if he puts the same kind of effort as that in obesity and heart disease.
I find the way cancer is handled by the medical community mind-baffling: everything that is done weaken the immune system tremendously to the point that I’ve wondered did the people I know who died of cancer, really die from it or from the mind boggling array of drugs and industrial strength pain killers?
Dr. Davis at the Heart Scan Blog writes this, as he is listing ways to reduce C-reactive protein levels:
“–Not allowing saturated fats to dominate–Yes, yes, I know. The demonization of saturated fat conversation has been largely replaced by the Taubesian saturated fat has not been confidently linked to heart disease conversation. But controlled feeding studies, in which a single component of diet is manipulated (e.g., saturated vs. monounsaturated vs. polyunsaturated fat) have clearly shown that saturated fats do activate several factors in the inflammatory response.”
A response?
I disagree. It’s a question worthy of a post versus a comment response.
Saturated fats can increase inflammation, but this is an indirect or transient effect. PUFAs are the main cause of inflammation – eating a lot of them or having a lot of them in your body will make you more vulnerable to damage by pollution, toxins, stress, etc. Saturated fats make the body stronger and more resistant to disease. They are falsely demonized. Long-term studies I have seen show that saturated fats reduce mortality from poisoning, various chronic diseases, asthma, and other auto-immune diseases. The fear of saturated fat is misplaced. We should be afraid of PUFA vegetable oils and foods that contain large amounts of them, like farmed fish, excess nuts and seeds, conventional chicken and turkey, etc.
Also, a lot of the confusion comes from bad terminology. For example, when you ask someone what is a “saturated fat”, they will say coconut oil, cocoa butter, beef, butter, pork, chicken, eggs, and turkey. But those range from ~2% PUFAs (beef) to 23% PUFAs (chicken). So, you get conflicting results. PUFAs are definitely dangerous. PUFA oils like sunflower increase cancer a lot, even at low intakes like 3% of calories. Fats like chicken and turkey skin may have a similar toxic effect at say 10-15% of calories. Beef and coconut oil protect against cancer, unless the diet is supplemented with PUFA oils, as Taubes noted. Here’s a review paper.
http://cancerres.aacrjournals.org/cgi/reprint/45/5/1997
“In further studies, Carroll and Hopkins (3) demonstrated that
diets containing 3% sunflower seed oil (polyunsaturated fat) and
17% beef tallow or coconut oil (saturated fats) enhanced tu-
morigenesis as much as did a diet containing 20% sunflower
seed oil. Rats on these diets developed twice as many tumors
as those fed diets containing 20% of the saturated fats alone.
These observations suggest that there may be a requirement for
polyunsaturated fat in mammary tumorigenesis, which is not
satisfied by fats such as coconut oil or beef tallow, but can be
provided by adding 3% sunflower seed oil to diets containing
these fats. A recent paper by Cave and Jurkowski (6) also
showed that when the polyunsaturated lipid content (com oil) of
the diet fell below 3% there was a decrease in tumor incidence
in rats treated with W-methyl-W-nitrosourea. It is thought that
linoleate may be the essential fatty acid primarily responsible for
the tumor-promoting effect of unsaturated fat (14).”
My conclusion is that the typical American / Western Diet, high in PUFAs, causes disease. If PUFA oils are eaten at all, then you should avoid meat, eggs, dairy, etc. Conversely, if you’re eating meat, eggs, and dairy, then PUFA oils should be eliminated. They are prevalent in the processed foods Americans eat, as well as mayonnaise, salad dressing, most cooking oils used in restaurants, etc. I would focus on red meat, dairy, tropical oils (coconut and macadamia), small amounts of olive oil, wild ocean-caught fish, etc.
Although I agree with your conclusions, I wouldn’t put a whole lot of stock in the study you referenced since it was a rat study. I didn’t pull the study and read it, but certain strains of rats can develop tumors at the drop of a hat when given substances that don’t affect humans at all.
Having said that, though, I do completely agree that vegetable oils should be avoided at every turn.
Human studies have shown similar associations with PUFAs and disease. Chris Masterjohn has written about the China Study and debunked T. Colin Campbell’s conclusions. What the China Study really shows is that the more PUFAs and the less SFAs eaten, the more atherosclerosis progresses, whereas a high-SFA and low-PUFA diet reverses atherosclerosis. Also, the Chinese eat hardly any refined sugar (as Taubes noted). This is why the low-fat proponents have been brainwashed. They get people to eliminate vegetable oils and refined sugars and grains, along with animal fats. Then they claim that the reduction of fat was the key factor. They never go by the scientific method. They change several variables at a time.
http://www.cholesterol-and-health.com/Campbell-Masterjohn.html
There seems to be a deadly synergy between a high-fat, high-PUFA, and high-carb diet, esp if refined sugars are the main source of carbs. John Yudkin and others have noted that refined starch is a lot less harmful than refined sugar, calorie for calorie. Most people now eat huge amounts of PUFA oils (soy, corn, flax, safflower, cottonseed, canola, peanut, sunflower, rape seed, walnut, hempseed, etc. Plus, lots of refined sugar too. This diet is a disaster that only causes gradual degeneration and one chronic disease or another.
Agreed.