Friday, April 13, 2012
Paleo Postings: Paleo diet and supplementsA reader inquires:
Shouldn't the Paleo Diet itself contain the all the (expensive?) vitamins and minerals that you list as your dietary supplements?Not necessarily. While it is true that one can certainly obtain most essential micronutrients from regular dietary intake, doing so requires substantial attention to detail that many people, including me, are not willing to expend the time to do. Then there are matters such as Vitamin D. Ancestral humans spent most of their time outdoors and most hunter/gatherers lived closer to the equator than the bulk of the human population does today. Consequently, they had no difficulty synthesising sufficient Vitamin D from sunlight on their skin. To avoid deficiencies, some foods in the West are “fortified” with Vitamin D, principally milk and breakfast cereal. But these are two of the food groups (dairy and grain) which do not meet the paleo guidelines, so without a supplement you're quite likely to be deficient (unless you spend a lot of time in the Sun around the year). A doctor in practice in California (!) said that she routinely tests her patients (who are not on any special diets) and finds about 40% are deficient in Vitamin D. I view paleo primarily as a way to avoid substances which ancestral humans did not consume to which natural selection cannot (by its very mechanism) adapt those older than the age of last reproduction. Given that there is substantial biochemical evidence that these foods (in particular grain, and especially wheat and derived products) are linked to a variety of late-onset diseases, this bolsters the evolutionary argument. The connection between the consumption of highly glycemic foods (sugars, processed flour, etc.) and insulin resistance, which leads to obesity and type 2 diabetes, is extremely persuasive. Note also that in the paleolithic, individuals who survived the very high rate of infant and child mortality (which persisted until the advent of modern medicine and public health measures) and managed to live to age 15 could expect to live a mean 39 years more, for a total mean lifespan from birth of 54 years. If you're a person today who hopes to enjoy a mean lifespan from birth of around 80 years, you become interested in things such as antioxidants, micronutrients which prevent loss of bone mass and calcification of soft tissues, and dietary components which reduce systemic inflammation, which can have a wide variety of deleterious consequences. It is possible to obtain these from diet (after all, the molecules in supplements are mostly extracted from vegetable sources), but it would be quite an effort to balance all of them. For example, you can get all of the zeaxanthin and lutein recommended to prevent or slow macular degeneration in the eye and the development of cataracts by eating a large spinach salad every day. But would you want to, and would you keep it up? It's a lot easier to take a pill and be sure (especially as most of these substances are water soluble and pose no risk of overdose).
Posted at April 13, 2012 20:07