In the last three weeks, I have run into many salutes to cooking. Not the pleasures of the table, nor the pleasure of keeping the ol' bod alive and functioning but the use of fire to change the chemical composition of food. Until recently, I thought of fire for light at night and heat when needed. Here, halfway to the north pole, we are aware of the need to conserve body heat or die. But a local retired dietician, a video from the Australian university of New South Wales, a TED talk by a brain scientist and the impressive book that several friends urged me to read, "Sapiens", have all pointed out that only humans cook. They all say that we have big, energy-consuming brains that would require 5 to 9 hours a day of eating without cooking. The basic idea is that high calories foods such as wheat, rice and potatoes don't yield those to the human body without being cooked.
You always hear that we are the only animals with this or that: language, writing, photography, musical instruments, cars and what not. I am reasonably confident that you can say we are the only animals that cook. Claude Levi-Strauss, the French anthropologist and more, examined the culture of the dining table and the manners of the table. Another writer in this area is the interesting Margaret Visser. She is the author of "Much Depends on Dinner", which I listened to but is available as a book on Amazon and an audio book and a downloadable PDF file from the internet.
But as of about 2009, the Harvard "biological anthropologist" and primatologist Richard Wrangham said in an interview in Discover magazine that until the last few years, little or no research had been done on the difference to a human body between the calorie extraction of cooked food and raw. He is the author of Catching Fire: How Cooking Made Us Human. He says in that interview:
About 25 years later, it occurred to me that my experience in Gombe of being unable to thrive on wild foods likely reflected a general problem for humans that was somehow overcome at some point, possibly through the development of cooking. (Various of our ancestors would have eaten more roots and meat than chimpanzees do, but I had plenty of experience of seeing chimpanzees working very hard to chew their way through tough raw meat—and had even myself tried chewing monkeys killed and discarded by chimpanzees.) In 1999, I published a paper [pdf] with colleagues that argued that the advent of cooking would have marked a turning point in how much energy our ancestors were able to reap from food.
To my surprise, some of the peer commentaries were dismissive of the idea that cooked food provides more energy than raw. The amazing fact is that no experiments had been published directly testing the effects of cooking on net energy gained. It was remarkable, given the abiding interest in calories, that there was a pronounced lack of studies of the effects of cooking on energy gain, even though there were thousands of studies on the effects of cooking on vitamin concentration, and a fair number on its effects on the physical properties of food such as tenderness. But more than a decade later, thanks particularly to the work of Rachel Carmody, a grad student in my lab, we now have a series of experiments that provide a solid base of evidence showing that the skeptics were wrong.
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