Does Eating Meat Make Us Smarter?

There's been a lot of discussion lately on Change.org and the foodie blogosphere on the age-old omnivore-versus-vegetarian diet. Many meats are more sustainably raised these days, but the USDA recently updated its nutritional recommendations to suggest a mostly plant-based diet, a la Michael Pollan. So which diet is better for the earth? And what about for one's health?

Questions about the best eating choices are quite contentious, and will likely be debated so long as humans continue to eat. A new report adds another issue to the mix, and it's sure to fuel the omnivore-veggie debate even more: Does eating meat actually make folks smarter?

In an effort to answer that question, NPR recently produced a story that analyzed the origins of omnivorism. Millions of years ago, humans based their diets on a foraging and gathering lifestyle, consuming a variety of fruits, nuts, tubers, and berries. These vegetarian vittles, while tasty, didn't provide a whole lot of protein, so people needed to consume vast quantities in order to stay energized. That meant that people needed big bellies to take in all that food, with most of the body's energy reserves spent on digestion.

But while big bellies held a lot of food, they limited what could be held in humans' brains. As NPR reported, "'You can't have a large brain and big guts at the same time,' explains Leslie Aiello, an anthropologist and director of the Wenner-Gren Foundation in New York City, which funds research on evolution. Digestion, she says, was the energy-hog of our primate ancestor's body. The brain was the poor stepsister who got the leftovers."

So, according to Aiello and other anthropologists, a plant-based diet limited how much energy could be devoted to the brain. Which makes sense when you consider the fact that the brain uses about 20 times as much energy as the equivalent amount of muscle anywhere else in the body. Then, 2.3 million years ago, people began eating meat. More energy went to the head, so humans developed bigger brains and smaller guts. They became smarter and more evolved, creating more sophisticated tools. For these reasons, many anthropologists consider the dawn of omnivorism to be a significant step in human evolution. In other words, eating meat made folks more intelligent.

But what about nowadays? According to the U.N., livestock production accounts for about 18 percent of the world's greenhouse gas emissions, the leading substances creating global warming. The amount of energy it takes to produce meat is significantly higher than the energy it takes to create the equivalent amount of calories from vegetables. Plus, while sustainably raised meats are starting to take off, the American landscape is still littered with factory farms, which produce a ton of pollution. Eating meat may make folks smarter, but the way the stuff is produced can be pretty darn asinine.

Looking back on history provides an enlightening view on how becoming omnivores helped humans evolve. But eating meat now sparks so much controversy even within the sustainable food crowd. I don't have a hard and fast rule for which diet provides the most benefits for the earth and folks' health, but I find the contentiousness over this issue to be incredibly intriguing. So what do you think, readers? What's the smartest dietary choice people can make?

Photo credit: Mike_fleming via Flickr