Wednesday, October 8, 2008

One Last Thought

In Dr. Lindeberg's paleolithic diet trial, subjects began with ischemic heart disease, and glucose intolerance or type II diabetes. By the end of the 12-week study, on average their glucose control was approaching normal and every subject had normal fasting glucose. Glucose control and fasting glucose in subjects following the "Mediterranean diet" did not change significantly. He didn't report changes in cardiovascular risk factors.

Why was the paleolithic diet so effective at restoring glucose control, while the Mediterranean diet was not? I believe the reason is that the Mediterranean diet did not eliminate the foods that were causing the problem to begin with: processed grains, particularly wheat. The paleolithic diet was lower in carbohydrate than the Mediterranean diet (40% vs 52%), although not exceptionally so. The absolute difference was larger since the paleolithic dieters were eating fewer calories overall (134 g vs 231 g). When they analyzed the data, they found that "the effect of the paleolithic diet on glucose tolerance was independent of carbohydrate intake". In other words, paleolithic dieters saw an improvement in glucose tolerance even if they ate as much carbohydrate as the average for the Mediterranean group.

This study population is not representative of the general public. These are people who suffered from an extreme version of the "disease of civilization". But they are examples of a process that I believe applies to nearly all of us to some extent. This paper adds to the evidence that the modern diet is behind these diseases.

A quick note about grains. Some of you may have noticed a contradiction in how I bash grains and at the same time praise Nutrition and Physical Degeneration. I'm actually not against grains. I think they can be part of a healthy diet, but they have to be prepared correctly and used in moderation. Healthy non-industrial cultures almost invariably soaked, sprouted or sourdough-fermented their grains. These processes make grains much more nutritious and less irritating to the digestive tract, because they allow the seeds to naturally break down their own toxins such as phytic acid, trypsin inhibitors and lectins.

Gluten grains are a special case. 12% of the US public is though to be gluten sensitive, as judged by anti-gliadin antibodies in the bloodstream. Nearly a third have anti-gliadin antibodies in their feces [update- these two markers may or may not indicate gluten sensitivity. SJG 2011]. Roughly 1% have outright celiac disease, in which the gut lining degenerates in response to gluten. All forms of gluten sensitivity increase the risk of a staggering array of health problems. There's preliminary evidence that gluten may activate the innate immune system in many people even in the absence of antibodies. From an anthropological perspective, wherever wheat flour goes, so does the disease of civilization. Rice doesn't have the same effect. It's possible that properly prepared wheat, such as sourdough, might not cause the same problems, but I'm not taking my chances. I certainly don't recommend quick-rise bread, and that includes whole wheat. Whole wheat seemed to be enough to preserve glucose intolerance in Lindeberg's study...


Pasi said...

When you eat less carbs and less calories you have to (and you can--> lower insulin) use more animal fat from your own fat storage.

Could increased use of excess visceral and liver fat be an answer for improved glucose control on paleolithic diet subjects?

brian said...


I tend to agree that grains can be part of a healthy diet. Just not necessarily in today's times. It takes a concerted effort to consume them in a healthy fashion. And most people just don't have the time or inclination to do it.

It's much easier to go wheat and gluten (and bad carbs) free.


Dave said...

Hi Stephan. I've been thinking about grains recently as well. In particular, archaeological evidence apparently shows a major change in skeletal structure and dental health at the point where agriculture was introduced. Do you know if this only occurred for those cultures eating wheat, or did it also happen to corn and rice-based agriculturists? Did populations exhibiting this change "detoxify" their grains?

The skeletal changes may be an independent issue from the diseases of civilization, but it still seems like a useful question.

Anna said...

Stephan, have you seen this New Yorker article on stature data and history?

Anonymous said...

I have celiac disease. How do gluten free flours fit into this lifestyle? I make breads with gluten free flours.

Stephan Guyenet said...


That is very plausible.


Agreed. Grains have their advantages though. They're inexpensive and they keep well.


Those changes occurred wherever grains were adopted, whether it was wheat, rice or corn. I'm not sure how these people were preparing their grains. The other thing is I'm not sure how much they were consuming. The problem may have been that they were eating grains to the exclusion of more nutritious animal foods.

What I do know is that in Nutrition and Physical Degeneration, there are examples of cultures that eat grains and don't show signs of grain damage. They all ate some amount of nutrient-dense animal food.

Stephan Guyenet said...


Thanks, I will check that out.


It would be wise to sourdough ferment your flours if you want the most nutritious bread. I'm sure you could make a sourdough start for non-gluten breads.

Stephan Guyenet said...


I just read the article you linked to. It's interesting. It bothers me that they leave it at income inequality as if that were an explanation. It's only a hint of an explanation.

It's interesting that the US is lagging behind other parts of the world in height and health; it must be due to our deplorable food culture. We're the fattest, we're getting taller the slowest, we're the least healthy for our income level. When are we going to wise up?

Unknown said...

One of the previous posts made me think about how certain foods might be habit forming and if those foods are also cheap, widely available and a symbol of status they're likely to be consumed in unhealthy portions as well. I think these are factors in diseases of civilization in addition to switching to a diet one's body might not be well adapted for.

Anna said...

Along long time ago I remember reading that "enrichment" requirements for processed foods came about because when young men were called up for the drafts, especially during WWII, there were so many men unfit for service due to nutritional deficiencies.

Food supplies changed a great deal in the age of industrialization (earlier than many people realize), from home and industrial canning technology around the time of the American Civil War, to mass-produced refined flour in the 1880s to relative abundance of inexpensive meat around the turn of the century due to easier transport and the rise of the meat packing industry (meat consumption went down for a substantial period in the early 20th century after publication in 1906 of Upton Sinclair's exposé, The Jungle), the increased substitution of processed vegetable oils in the late 19th and 20th centuries, new chemical food preservation processes after the WWs, etc. The dietary and nutritional status changes also seem to coincide pretty well with the rural to urban population changes, too, when home-raised food shifted to commercially sourced foods.

For instance, one could be cash-poor, but with a family cow, a pig or two, and some chickens and a vegetable garden, a rural or even semi-rural family could still eat quite well. But a more cash-based, rich or poor, urban family would have to rely on what they could source from urban grocery stores (and the rich might be more prone to choosing the "new and improved" processed convenience foods) and therefore might not consume as many nutrients.

Stephan Guyenet said...


Those are all plausible factors


Good point. These changes have been happening for a long time.

Robert Andrew Brown said...
This comment has been removed by the author.
Buccaneer said...

Fruits and Oats for breakfast

Brown rice and/or sweet potato for lunch/dinner

Thats the only type of grains I would eat. Is that ok?