I doubt there's anything terribly wrong with cutting out dietary grains, but the basis for a "paleo" diet appears to rest on two principal assumptions: 1. Pre-

I doubt there's anything terribly wrong with cutting out dietary grains, but the basis for a "paleo" diet appears to rest on two principal assumptions: 1. Pre-agricultural humans didn't eat grains 2. The human digestive system has evolved little since the introduction of agriculture The problem is that both of these assumptions are dubious at best. If paleolithic humans didn't eat grains, then how were grains ever domesticated in the first place? Obviously, someone was eating grains in the wild, and evidently over time people learned how to cultivate them. I have no trouble believing that the paleo diet contained far fewer grains than the typical post-agricultural diet, but that suggests eating select whole grains in moderation, not eliminating them entirely. In addition, the idea that ten thousand years isn't enough time for substantial evolution is clearly wrong. The reason the New World was ravaged by smallpox, plague, influenza, etc., upon contact with Europeans was because Americans (in the generalized sense) lacked the resistance that Eurasians had evolved in the time since the invention of agriculture. Meanwhile, some people (especially northern Europeans) have no trouble digesting milk because they evolved the ability to metabolize lactose—presumably a recent innovation, since dairy animals were domesticated around the same time as grains. (Yet many "paleo" advocates also recommend eschewing dairy.) Indeed, "lactose intolerance" is a misnomer; what's remarkable is that anyone is lactose-tolerant—lactose-tolerant humans are the only mammals to produce the necessary lactase enzyme as adults. There is every reason to expect that a similar evolutionary process has led to an enhanced ability to digest grains; it may not be true, but it should be the null hypothesis. In short, the basic idea of eating nutrient-dense foods is based on sound science, but the complete elimination of perfectly healthy foods such as whole grains and dairy doesn't have any basis in reality.