How Cooking Made us Human

I have just finished reading Richard Wrangham's 2009 book Catching Fire: How Cooking Made Us Human. This book contains aspects of anthropology and gastronomy, two of my favorite hobby subjects.

The book's premise is that cooking food has made us what we are today, and without fire, we may be still swinging around in trees. Wrangham sets in right away and discredits the popular movement of eating only raw food. Demi Moore does it, David Bowie does it, and countless others. The biggest claim from the raw-foodists is that there are enzymes in raw food that are critical for digestion, enzymes which are destroyed by heating.

Not only have these "critical enzymes" thus far eluded scientific research, but Wrangham points out numerous studies and revealing examples throughout history that the exact opposite is true: Humans cannot properly digest raw food enough to maintain good health.

The raw-foodists like to point out that a raw food diet is "natural", but they fail to understand that it is natural for apes and monkeys, but it is not natural for humans. They fail to understand that the human body has evolved and adapted to a cooked food diet. Everything about our eating system-- our small mouth and lips, small teeth, small jaw muscles, small stomach, short digestion cycles, and short intestines -are all at a huge disadvantage for processing raw food, but which handles cooked food very well.

Another interesting point that Wrangham makes is that the human body supplies at least 20% of its energy to fuel our brains. This is far more than any other animal. Like a supercomputer, it takes a lot of juice to keep all that intelligence going. This energy demand calls for a well-tuned and sophisticated digestion system and diet.

Which brings us to the Expensive Tissue Theory. This theory states that either the digestive system or the brain are the big consumers of energy, but not both. Animals with larger digestive systems (which require more energy to operate) tend to have smaller brains. When looking at all the primates, the size of the brain is inversely proportional to the size the digestive system. For primates like gorillas, they have a lengthy and energy-consuming digestive system. For humans, we have a power-hungry brain, but a small digestive system. This system is adapted to eating cooked foods where nutrients are readily available with considerably less effort to digest.

Wrangham points to two periods in human evolution when our brains increased dramatically in size and theorizes, based on the Expensive Tissue idea, that a change in diet caused each increase. The first time was a transition from Australopithecines to Homo erectus 2 million years ago. This brain size increase is attributed to an increase of meat in the diet. The second large increase in brain size was from Homo erectus to Homo heidelbergensis roughly 500,000 years ago. This has been attributed to cooking food.

Wrangham also discusses hunter-gatherer societies and some of the earliest "human" behaviors exhibited by our ancestors. While gorillas and chimpanzees spend nearly half their waking day chewing raw food, eating cooked food allowed men to spend more time hunting, which brought more meat into their diet. Fire and cooking made this type of society work and developed what we now call family units. Cooking is, in essence, the cornerstone of humanity.

So next time you are in the kitchen cooking, realize that you are participating in one of the earliest human industries, one that advanced our species beyond our raw-food chewing cousins, and it is a very human thing to do.