You are what your ancestors ate, part 1

Ann Gibbons has a long news article in the current Science reporting on an interdisciplinary conference on recent human diet evolution (“What’s for Dinner? Researchers Seek Our Ancestors’ Answers”). The article covers a lot of ground, from Michael Richards’ work on the isotopic signature of diet in early Upper Paleolithic people, to Bill Leonard’s work on diet adaptations in Siberian reindeer herders, to Jonathan Wells’ work on maternal nutritional status and epigenetics.

It’s a good “why evolution matters to today’s nutritional choices” article.

A section of interest to me:

The agricultural revolution favored people lucky enough to have gene variants that helped them digest milk, alcohol, and starch. Those mutations therefore spread among farmers. But other populations remained more carnivorous, such as the Saami of frigid northern Norway, whose ancestors herded reindeer. Among Saami ancestors, genes to digest meat and fat efficiently were apparently favored. One gene variant, for example, makes living Saami less likely to get uric acid kidney stonescommon in people who eat high-protein dietsthan are people whose ancestors were vegetarian Hindus and lack this gene variant, says geneticist Mark Thomas of University College London (UCL).

I’ll have more on a similar topic later – recent shifts in genes due to agricultural subsistence has become a favorite subject of local interest. One would think I might get some funding from the Wisconsin dairy industry for this, but nothing so far…

There is an unresolved tension in the article: Is there a better diet for everyone? Clearly some populations have undergone large recent diet changes with bad consequences; the same bad outcomes occur in some people despite possibly adapting to new diets for thousands of years. And yet, every metabolic or diet-related syndrome is variable, and we know that some genes related to digestion and metabolism have rapidly changed. “Westernization” is not as simple as it seems, nor is agriculture (or, for that matter, pastoralism) – and the responses to each vary for stochastic reasons in different populations.

It’s a good interesting complexity, in a field where simple categorical statements can get a lot of attention.