In this TED talk, Heribert Watzke makes the argument that cooking our food was central in modern humans becoming who we are. He also shows how the neurological system around the gut is a second brain. Below the video are my notes.
He says that our teeth "show" that we are made to eat cooked food. Food that is mushy and soft, not very fibrous. He says that cooking food changed who we are- we not just "omnivores", we are the animals who eat cooked food. The technology of cooking allowed us to develop our huge brains, because our brains use a tremendous amount of energy, more than raw food can provide for us. When we began cooking, our brains grew and our guts shrank. Our gut shrank to 60% of a primate gut of the same body mass. This is because cooked food is easier to digest.
He breaks down our 5 tastes into 3 that sustain us- sweet for energy, salty because we need salt to maintain electrolytes, and umami (the taste of protein, this is the taste that MSG and other dietary free glutamate activates). Our other two senses, bitter and sour, protect us against poisonous and rotten materials. He says that our guts play a role in providing feedback when we have digestive discomfort (gas, bloating, stomach aches) tell us that something went wrong.
Our gut is connected to our limbic system (emotional part of the brain) and the two communicate to make decisions. The gut is the largest part of our immune systems, defending our bodies. Our gut brain has about the same number of neurons as a cat brain. It has the same diversity of neurons that are found in our "big brain". It has autonomous microcircuits- it thinks for itself. Our gut brain controls motor movements and reflexes such as gagging and vomiting, and controls the secretion of enzymes and hormones to aid digestion. (My thought- what this means is that digestive disturbances are a manifestation of neurological dysfunction, just as neurological disturbances in the brain are. Gut injury is "brain injury".)
He says that how we cook is a way to communicate with the gut- maybe we can learn how to cook so as to send the signals that we want to send. (My thought- maybe this also means that the dramatic changes in how we prepare our foods that have occurred very recently are having more of an effect on us than we realize. This seems to me to be an argument for returning to traditional cooking practices until we know more about what effect changing these practices will have.)
