National Geographic : 2014 Sep
#futureoffood 51 struggled to answer key questions about this tran- sition. Was agriculture a clear step forward for human health? Or in leaving behind our hunter- gatherer ways to grow crops and raise livestock, did we give up a healthier diet and stronger bod- ies in exchange for food security? When biological anthropologist Clark Spen- cer Larsen of Ohio State University describes the dawn of agriculture, it’s a grim picture. As the earliest farmers became dependent on crops, their diets became far less nutritionally diverse than hunter-gatherers’ diets. Eating the same domes- ticated grain every day gave early farmers cavities and periodontal disease rarely found in hunter- gatherers, says Larsen. When farmers began domesticating animals, those cattle, sheep, and goats became sources of milk and meat but also of parasites and new infectious diseases. Farmers suffered from iron deficiency and developmental delays, and they shrank in stature. Despite boosting population numbers, the lifestyle and diet of farmers were clearly not as healthy as the lifestyle and diet of hunter- gatherers. That farmers produced more babies, Larsen says, is simply evidence that “you don’t have to be disease free to have children.” The real Paleolithic diet, though, wasn’t all meat and marrow. It’s true that hunter-gatherers around the world crave meat more than any other food and usually get around 30 percent of their annual calories from animals. But most also endure lean times when they eat less than a handful of meat each week. New studies suggest that more than a reliance on meat in ancient hu- man diets fueled the brain’s expansion. Year-round observations confirm that hunter- gatherers often have dismal success as hunters. The Hadza and Kung bushmen of Africa, for ex- ample, fail to get meat more than half the time when they venture forth with bows and arrows. This suggests it was even harder for our ances- tors who didn’t have these weapons. “Everybody thinks you wander out into the savanna and there are antelopes everywhere, just waiting for you to bonk them on the head,” says paleoanthropologist Alison Brooks of George Washington University, an expert on the Dobe Kung of Botswana. No one eats meat all that often, except in the Arctic, where Inuit and other groups traditionally got as much as 99 percent of their calories from seals, narwhals, and fish. So how do hunter-gatherers get energy when there’s no meat? It turns out that “man the hunt- er” is backed up by “woman the forager,” who, with some help from children, provides more calories during difficult times. When meat, fruit, or honey is scarce, foragers depend on “fallback foods,” says Brooks. The Hadza get almost 70 percent of their calories from plants. The Kung traditionally rely on tubers and mongongo nuts, the Aka and Baka Pygmies of the Congo River Basin on yams, the Tsimane and Yanomami In- dians of the Amazon on plantains and manioc, the Australian Aboriginals on nut grass and wa- ter chestnuts. “There’s been a consistent story about hunt- ing defining us and that meat made us human,” says Amanda Henry, a paleobiologist at the Max Planck Institute for Evolutionar y Anthropology in Leipzig. “Frankly, I think that misses half of the story. They want meat, sure. But what they actually live on is plant foods.” What’s more, she found starch granules from plants on fossil teeth and stone tools, which suggests humans may have been eating grains, as well as tubers, for at least 100,000 years—long enough to have evolved the ability to tolerate them. The notion that we stopped evolving in the Paleolithic period simply isn’t true. Our teeth, jaws, and faces have gotten smaller, and our DNA has changed since the invention of agri- culture. “Are humans still evolving? Yes!” says geneticist Sarah Tishkoff of the University of Pennsylvania. One striking piece of evidence is lactose toler- ance. All humans digest mother’s milk as infants, but until cattle began being domesticated 10,000 years ago, weaned children no longer needed to digest milk. As a result, they stopped making the The magazine thanks The Rockefeller Foundation and members of the National Geographic Society for their generous support of this series of articles.