Cooking and fire is another interesting and controversial topic. Fire has several uses, it can be used to protect from predators, for warmth and for cooking. It was also used to clear areas for agricultural use and probably security in earlier times.
A debate remains about whether cooked food or raw food is better for you. There is no correct answer because some raw foods are better left alone and some better cooked.
The discussion amongst Paleobiologists about the origin of fire and its use for cooking rages on. The record in archaeological sites for the use of fire is one hotly debated topic.
Cooking is essential and is key to the extraction of nutrients and energy from foods. There is plenty of data demonstrating that learning how to use fire to breakdown and alter raw food products was a significant evolutionary step in the story of human development. Although there is debate about when our ancestors developed this ability it was a long time ago, somewhere between half to one million years ago. That's before the split into Neanderthals and humans occurred. There is some discussion in the scientific literature about whether the failure to use fire for cooking was what ultimately decided the fate of Neanderthals. The reality is we don't know. For Homo sapiens cooking food is probably one of the key reasons that our ancestors were able to settle and survive in any habitat in the world.
Extracting Energy Efficiently
Our nervous system, in particular the brain requires immense amounts of energy and realistically the only way that we can extract than amount of energy from food sources is by changing the basic structure of food. In fact when you look at the fossil record of early human ancestors brain size increased dramatically at the same time teeth became smaller and jaws weaker. Brain size increases can only happen if there is more energy. Teeth can only get structurally weaker and smaller if food is softer. This occurs if food is crushed and pounded and or cooked.
The other bit of evidence that shows that alteration of raw food through the process of grinding, crushing and cooking was necessary for humans to thrive is the length of our gut. We have one of the shortest intestines of any mammal and certainly the smallest bacterial colony for breaking down plant fibres. Although crucial for health our gut bacteria colony provides very little in the way of calories to our body, contributing little to our overall energy needs. They also provide very little protein to our bodies. This is quite different from other mammals where bacteria not only contribute to energy supplies but also protein. So with a short gut we need to be very efficient at extracting energy and nutrients from our food and indeed this is the case. But the the only way we can do this is by altering food from its raw state and a very important part of this is the process of cooking.
We have been pounding grain, vegetable matter and meat for millennia improving palatability and energy extraction. There is a lot of data demonstrating that crushing and cooking food improves its digestibility, and this applies to both animal and plant sources. Milling and grinding are modern and efficient methods replacing the old-fashioned and long used pestle and mortar, in itself an evolution of rock on rock.
In spite of this there remains a debate about whether cooked food or raw food is better for you. There is no correct answer because some raw foods are better left alone and some better cooked.
“ Insects are definitely nicer to eat cooked than raw. A staple in many parts of the world.”
Let’s look at energy foods, the starch foods first. The earliest used were roots and tubers like yams. The energy is stored in the form of starch. Starch (glucose) is almost inextricable without cooking as tubers are too tough to chew, inedible and indigestible. Grain like rice, millet and later wheat, barley and rye are all nutritionally better when cooked because they are unpalatable uncooked .
At the other extreme many fruits and berries, but not all, lose nutritional quality if cooked. Vegetables hit a middle ground. Cooking can enhance nutritional value in some and degrade it in others.
Meats on the whole are improved by cooking. Certainly with some exceptions like liver, flesh is difficult to chew and digest when in its raw state. Cooking softens it and usually makes it more palatable. Cooked insects are definitely nicer to eat than raw. A staple in many parts of the world.
Different methods of cooking also have a significant impact on food quality. Boiling food in water is the most damaging in terms of decreasing nutrient value across all food types. Other methods, steaming, grilling and baking all have pluses and minuses.
There is a lot of worry about microwaving food. The way this process works is by heating the water found in most foods. The microwaves vibrate the water molecules creating hot water and this cooks the food from the inside out at 100 degrees rather than other methods where we cook food from the outside in. This external heating requires much higher temperatures. As the process is faster than other cooking methods and the temperatures are relatively low, microwaving food is not only safe but preserves the nutrient value of food more than other methods. In spite of the ongoing worries it turns out that microwaving food in a glass container is the possibly the least degrading method of cooking for many foods.
In summary it is true to say that all cooking methods degrade some of the nutrient value of foods, with some definite exceptions, even though the process increases the availability of energy within the food. Cooking was critical to the evolution of the brain in energy trade off evolution. More energy for our brain development meant less for the gut and muscles. We traded strength for intelligence. From an evolutionary perspective this has proven to be a great success.
Cooking serves another purpose. It developed as part of our cultures, in fact food and how we prepare it often defines different cultures and clans. We all recognise Italian or French cooking from Europe, or Thai, Chinese and Indian cuisine from Asia. There is nothing new about this. Peoples throughout history have prepared what is locally available supporting the fact that humans are extremely adaptable, flexatarian and omnivorous. As culture is important to cultural health, cooking has an important role in psychological wellbeing.
On every continent we celebrate special festival dates during the year, in the US people look forward to Thanksgiving, and in Europe the Christian celebrations of Christmas, the Jewish community Hanukkah, the Chinese celebrate New Year and in India Diwali. These celebrations share significant common themes. They bring people of the same culture together, most particularly families and they all have special traditional foods and dishes often unique to that festival. They also share something else, on the whole happiness and laughter. Members of the family come together to prepare culturally traditional meals in styles unique to that family. These meals are typically produced in a cooperative and mutually supportive fashion which is an important bonding process that not only builds relationships within the group but has profound impacts on individual members wellbeing. Even in our daily lives we often meet for coffee, go out of a meal, have business meetings over dinner. Special food that are not part of our daily diet is a common theme to these events. Most of us don’t go out for a special junk food dining experience. Most people don’t propose over a McDonalds!
We all might want to reflect on this and I discuss it more in the book’s chapter on contentment and happiness.
So the preparation and cooking of food serves a function over and above its nutritional value. It is an important component of defining a clan and its culture. When well intended dietary advice is given this needs to be part of the consideration given to meal planning.