Lactose Tolerance Is an Evolutionary Puzzle
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People like to say that you are what you eat, but the truth is more like this: In the broad course of human history, we become what we eat. The contents of our ancestors’ dinner tables have slowly but surely left their signatures in the human genome. Learning to cook and soften our food was likely the major driver of our teeth shrinking during the Neolithic age. The lightening of Europeans’ skin is in part a product of dietary changes associated with farming.
The genes that let some adults drink milk with no attendant tummy troubles—a trait mapping European milk consumption throughout history suggests that humans owe the quick proliferation of lactose tolerance to a legacy of famine and disease that began thousands of years we became dairy fiends. In other words, lactose-intolerant people have been throwing back dairy for thousands and thousands of years. But whereas I think moaning to my boyfriend about my is just the sign of a tasty, tasty meal, our lactose-intolerant ancestors were more likely putting themselves through the digestive wringer just so they could survive.
