My last post here detailed just a few relatively easy-to-apply lifestyle changes that might make good New Year resolutions. One of them, was to eat a ‘primal’ diet ” essentially a diet based on the foods we’ve been eating the longest in terms of our time on this planet. The record suggests that for the vast majority of our time here we’ve subsisted on a diet made up of animal foods (e.g. meat, fish and eggs), fruit, vegetables, nuts and water. The exact make-up of the diet would have varied according to precise location and environment (e.g. relatively more animal and less plant food further from the equator), but what our ancestral diet most certainly did not contain was piles of grain and dairy products, along with things like refined vegetable oils, refined sugar, artificial sweeteners and processed, chemicalised fats found in many foods including margarine.
Just a couple of days ago in the American Journal of Clinical Nutrition was published an editorial which reminds us of the potential importance of getting back to our nutritional roots [1]. In this editorial, the authors make the point that our genetic make-up was selected for behaviours and an environment (including diet) for humans appearing in Africa between 50,000 and 100,000 years ago. Now, since that time, certain adaptations have taken place (e.g. skin colour and the retaining after infancy of the milk sugar digesting enzyme lactase by some of the human population). However, as the authors point out, core biochemical and physiological processes have been preserved [2].
As humans migrated around the globe and cultures changed, the authors argue, our diet and activity changed in a way that made it impossible for genetic evolution to keep pace. The result? Complex degenerative diseases including atherosclerosis (the usual underlying process in heart disease and stroke), several forms of cancer, obesity and type 2 diabetes.
According to the authors of the editorial, few would deny that conventional nutritional advice is not working. And they suggest that what would help would be a more rapid shift in thinking towards a diet that gets us closer to humanity’s biological baseline. They quote a recent scientific paper [3] which asserts that It is difficult to refute the assertion that if modern populations returned to a hunter-gatherer state then obesity and diabetes would not be the major public health threats they now are.
As we enter a new decade, perhaps more than any other time in history do we need a radical rethink of what truly constitutes a healthy diet. For too long now we have been ‘fed’ the idea that the low-fat, high-carb diet is king. The results of this persistent public health message, and our acting on it, appear to have been an unmitigated disaster judging by the soaring rates of obesity and diabetes we’ve seen in westernised cultures.
Enough is enough. There is more than enough evidence, I think, to demonstrate that looking to our nutritional past will be how we can improve our health and the health of future generations.
References:
1. Eaton SB, et al. Diet-dependent acid load, paleolithic nutrition, and evolutionary health promotion. Am J Clin Nutr 30 Dec 2009 [epub ahead of print]
2. Smith E, et al. Universality in intermediary metabolism. Proc Natl Acad Sci USA 2004;101:13168-73
3. O’Rahilly S. Human genetics illuminates the paths to metabolic disease. Nature. 2009;462:307-14.
