Consider a 2006 experiment filmed by the BBC. Nine participants spent twelve days living in a tented enclosure at the Paignton Zoo in Devon, England. Their “Evo” diet comprised up to eleven pounds of raw vegetables and fruits; similar to what apes eat. Midway through, a little oily fish was added, adding a hunter-gatherer dimension to the diet. Although the volunteers consumed approximately 2300 calories a day, all experienced weight loss, and an improvement in blood pressure and cholesterol levels.
In anthropological terms, the duality of raw versus cooked has long been associated with the dichotomy between the natural world and the world of human culture. Imagine an axis where elements of natural origin fall along the "raw" side, and those on the "cooked" side are of cultural origin.
Richard Wrangham, in his new book Catching Fire, poses a related question: what behavior made us human? In this interesting and well-researched book he argues that the crucial turning point was neither controlling fire nor eating meat, but cooking.
The evolution of Homo erectus, an early bi-pedal hominid with an upright stance, and a smaller brain than modern humans, is commonly attributed to behaviors such as hunting, tool use and the consumption of meat. Wrangham focuses instead on cooking and the possibility that gathering around a fire with cooked food are what changed the path of hominid development.
Cooking increases the nutritional value of plant food and meat by facilitating faster digestion and more efficient extraction of nutrients by the body. Compared to apes, humans have much shorter digestive tracts, and use less energy to digest food, because of the fact that it is cooked. This energy savings is diverted to other areas of our bodies, mainly into running a big and energy-expensive brain which consumes about 20% of our daily caloric requirement.
Chimpanzees and gorillas spend most of their time eating since they need to ingest large quantities of fruit and leaves. By contrast, evidence from modern hunter-gatherer societies indicates that humans need to spend as little as an hour a day eating if the food consumed is cooked.
Archeological evidence does support the theory that our ancestor Homo erectus started cooking, and that the cooking of food had far-reaching social consequences. Those include the possible emergence of a sexual division of labor (hunter/cook), food sharing (unique among primates), less time spent eating and more time available for developing specialization (tools).
So the next time you cook some vegetables purchased at the farmers market and sit down to share them with your family and friends, take a moment to consider how very different life would be if you could eat only raw foods.
