Richard Wrangham knows something about how human diets evolved. He’s a Harvard professor of anthropology, the curator of primate behavior biology at the Peabody Museum, director of a chimpanzee project in Uganda—and he’s willing to sink his teeth into his research. For example, Dr. Wrangham has found that “some of the fruits, seeds, and leaves that chimpanzees select taste so foul that I can barely swallow them. The tastes are strong and rich, excellent indicators of the presence of non-nutritional compounds, many of which are likely to be toxic to humans but presumably much less so to chimpanzees. Of the scores of chimpanzee foods I have tasted, I can imagine filling myself with only a very few species, such as wild raspberry, but alas, one rarely finds more than a handful of these delicious fruits at a time. Since cooking predictably destroys many toxins, we may have evolved a relatively sensitive palette.”
Dr. Wrangham’s taste test is part of a radical new theory in how anthropologists view evolution. His new book, Catching Fire: How Cooking Made Us Human (Basic Books), proposes that what fueled the dramatic increase in human brains is our ability to cook. Unlike other primates, who spend five hours a day chewing and even more hours digesting, humans can fuel themselves in minutes. Cooking was our most important fast-food revolution.
The energy advantages to cooking are enormous. For example, cooking eggs allows us to utilize 91 to 94 percent of the protein, as compared to only 51 to 65 percent for raw eggs. By the same token, the starch in cooked wheat and potatoes is about 95 percent digestible, while raw wheat starch is 71 percent digestible and raw potato only 51 percent. While cooking destroys some nutrients, the energy gains remain overwhelmingly positive. Wrangham reveals that all hunter-gather societies around the world cook their food and suggests that our teeth, jaws, and digestive systems have evolved such that a person in the wild without fire will typically starve.
Wrangham also suggests that the use of fire precipitated the division of labor and family bonds. Women gathered and cooked, while men hunted (or did nothing at all). A woman with a fire, despite spreading the smell of food for miles, was safe from other animals but needed a man to protect her from other men stealing her food.
Wrangham gently pokes at the current raw-food movements, and his theory raises interesting questions for all eaters. In a world of increasingly scarce resources, is it justifiable to choose a diet in which up to half the nutrients are flushed down the toilet? As Wrangham writes, “We fare poorly on raw diets, no cultures rely on them, and adaptations in our bodies explain why we cannot easily utilize raw food. Even vegetarians thrive on cooked diets. We are cooks more than carnivores. No wonder raw-foodism is a good way to lose weight.”
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