Diet And Recent Evolution
September 07, 2010, 08:50 PM
A+
|
a-
Print Friendly and PDF

It's common to assume that bread must be good for you because most people in Europe ate a lot of bread over the last few thousand years, so there would have been Darwinian selection for eating bread. No doubt that's true to a sizable extent.

Still, if you are of European descent, you probably aren't descended on average from the average person in European history. Consider it in the light of Greg Clark's findings in A Farewell to Alms: people of European descent tend to be descended from affluent Europeans, typically from successful farmers and landowners. Your ancestors may well, on average, have eaten more meat (or other expensive foods) than the farm hands they employed.

You may well have ancestors who could afford only bread and other ancestors who ate a lot of the roast beef of merrie old England (or wherever). Which complex of genes for dealing with diet you would end up with is hard to predict. You may differ a lot in which foods are best for you even from a sibling.

I think this may explain a little bit about the famous paradox of how many East Asians stay slender eating a heavily carbohydrate diet, a fact that helped motivate the government's and medical establishment's over-emphasis of grains in your diet in the later 20th Century. According to economic historians such as Clark and David Landes, East Asian cultures tended to maximize population density through early marriage. This in turn meant intensive grain farming to get as many calories out of an acre as possible. Which then means that East Asians tend to be selected for being healthy on a highly grain-based diet.

In contrast, Europeans tended to not have as much of the population boom / famine cycle as East Asians because they delayed marriage and childbearing until they could afford it. Rich girls in England married young, poor girls married later or not at all. This meant that the English could afford a richer diet because they didn't need to squeeze quite as many calories out of each acre, and could devote more land to growing protein and fat (e.g., cows).