Saturday, January 26, 2013

Paleolithic diets: Should we eat like our ancestors? | PCC Natural Markets

Paleolithic diets: Should we eat like our ancestors? | PCC Natural Markets

By the time modern humans emerged roughly 50,000 years ago, our ancestors had adopted an omnivorous diet of cooked starches, meats (including organs), nuts, fruit and other plant foods. Although very few hunter-gatherer groups survive today, we know they eat a wide range of diets, from the nut-based diet of the African !Kung, and the palm starch diet of New Guinean hunter-gatherers, to the meat- and fat-rich diet of the Arctic Inuit.

As Michael Pollan writes in "Food Rules," "There is no single, ideal human diet."

Modern hunter-gatherer diets, however, tend to have certain things in common. They don't rely heavily on foods that became dominant after the development of agriculture, including dairy, grains and legumes. Starch comes from root vegetables similar to sweet potatoes, potatoes and taro. But most important, they do not eat industrial, processed foods. Other aspects of lifestyle, such as physical activity, also differ from industrialized populations.
Modern research

A small group of researchers is beginning to test the idea that pre-agricultural "Paleolithic" diets might hold the key to improving modern human health. Dr. Lindeberg and his colleagues have conducted two remarkable clinical trials.

In the first, they recruited diabetic and pre-diabetic volunteers with heart disease and placed them on one of two diets: 1) a "Paleolithic" diet, focused on lean meat, fish, fruit, vegetables, starchy root vegetables, eggs and nuts, or 2) a "Mediterranean" diet focused on whole grains, low-fat dairy, vegetables, fruit, fish, oils and margarine. Over the 12-week study period, the Mediterranean group lost body fat and enjoyed an improvement in markers of diabetes. Of nine participants with diabetic blood sugar levels at the beginning of the study, four had normal levels by the end.

Those in the Paleo group fared significantly better. They lost 70 percent more body fat than the Mediterranean group and experienced a remarkable normalization of blood sugar. All 10 participants with diabetic blood sugar levels at baseline reached non-diabetic levels by the end of the study. It's important to note that the volunteers in Dr. Lindeberg's study were mild, early cases of diabetes. A second study of long-term diabetics showed that a Paleo diet did not cure them but it did improve their condition significantly.

Should we all eat a hunter-gatherer diet? Not necessarily. Human evolution did not end with the Paleolithic era. Each person carries a particular set of genetic adaptations that result from the unique dietary environment of his own ancestors, so it's important to emphasize that traditionally prepared grains, legumes and dairy can be healthy foods for many people.

Stephan Guyenet is an obesity researcher at the University of Washington. Visit his blog, wholehealthsource.org, to read more of his writing on nutrition and health.

Stephan is also a big proponent of the palatability school of low carb, and had a big debate with Taubes about that. Taubes focuses mostly on the role of insulin in hunger and fat deposition. Richard at free the animal is eating the potatoes because of (in part) what he learned from Stephan- that we overeat certain foods because they are nutritionally dense and taste good. So when we low carb, we also avoid most of the worst foods like cake and sweets, which we are prone to overeat anyways, because they taste awesome. The low carb diet is blander and less likely to make us binge. But we could achieve a similar effect with a bland yet nutritious food like potatoes. Now whether a starchy vegetable has the same health impact as meat is another question. But I think the ideas of Stephen and Richard are a pushback against the super extreme ketogenic zero carb wing of the low carb movement. So living in fear of healthy carbs is wrong, just as the low fat people, during their age, told us that as long as we cut out fat (the more extremely the better- Ornish), we would have great health and lose weight.

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