When Fire Met Food, the Brains of Early Humans Grew Bigger
November 10, 2012
By Dr. Mercola
Generally speaking, the larger the mammal, the larger its brain will be. Humans are a bit of an anomaly among primates, however, because we have the largest brain and number of neurons, but not the largest body. Great apes, for instance, have much bigger bodies than humans, yet much smaller brains.
How humans came to be so well endowed in the brain department has long been a mystery – but many theories abound, including the predominant one of access to animal-based omega-3 fats from seafood.
Another theory suggests it may, in fact, be cooking that allowed humans to develop so much brainpower.
Did the Advent of Cooked Food Grow Human Brains?
Your brain is a major consumer of the calories you consume in a day. Even though it makes up only about 2 percent of your body mass, it uses 20 percent of your calories!1
The size and number of neurons in your brain is, therefore, largely dependent on the number of calories you can consume in a day. Ancient humans had to graze constantly to find enough calories to live on, much the way apes and gorillas do today. There are only so many hours in a day, and raw, mostly vegetable, foods do not contain many calories, which together put a metabolic limitation on how big the brain could grow.
Writing in PNAS,2 researchers believe that it was the shift to a cooked-food diet that gave humans the extra calories they needed to allow their brains to get bigger.
“Absent the requirement to spend most available hours of the day feeding, the combination of newly freed time and a large number of brain neurons affordable on a cooked diet may thus have been a major positive driving force to the rapid increased in brain size in human evolution,” the researchers noted.3
They speculated that gorillas would need to spend another two hours a day eating to gain the extra caloric intake to allow their brains to grow as big as humans’, and pointed out that the cooked foods were likely easier to chew and digest, and may have released more calories in some cases.
In 2008, researchers similarly concluded that human brains “smartened up” – allowing for the use of tools and the creation of art and religion – due to the extra calories that became available when cooked food became widespread.4 Eating cooked meals, they said, would have lessened the energy needs of the human digestive system, thereby freeing up calories for the brain.
Does This Mean Cooked Food is Superior to Raw?
As some of you may know, I believe it’s very wise to strive to get as much raw food in your diet as possible. So how does this fit in with the theory that cooked food helped our brains get larger and smarter?
For starters, ancient humans ate a largely plant-based raw food diet. They may have had raw meat occasionally, but this was not significant portion of their diets. If you restrict your foods to raw plant foods only, as is advocated by many, it is my personal observation and belief you will likely see a radical decline in your health over the long term.
I personally try to eat about 85 percent of my food raw. And it’s likely that even when ancient humans moved their meals to the hearth, they still ate a far more significant portion of raw foods than people do today.
There are some cases where cooking does appear to release more nutrition – such as the lycopene content of tomatoes. However, by and large cooking your food, especially at high temperatures, destroys naturally occurring enzymes. Enzymes are proteins; catalysts to speed up and facilitate reactions in your body. In fact, some biochemical reactions will not even occur without these enzymes (you have about 1,300 of them).
So if all of your food is cooked, your body is going to be deficient in the enzymes it needs to function properly. It will also be lacking biophotons.
Living raw foods contain the biophoton light energy your body needs. Every living organism emits biophotons. It is thought that the higher the level of light energy a cell emits, the greater its vitality and the potential for the transfer of that energy to the individual who consumes it. The more light a food is able to store, the more nutritious it is. Naturally grown fresh raw vegetables, for example, and sun-ripened fresh fruits, are rich in light energy. The capacity to store biophotons is therefore a measure of the quality of your food.
The greater your store of light energy from healthy raw foods (this should not be confused with your vitamin D status, which is produced by the sun on your skin), the greater the power of your overall electromagnetic field, and consequently the more energy is available for healing and maintenance of optimal health.
The Modern “Cooked” Diet is Nothing Like the Ancient Cooked Diet
This is the other major point to consider, as most of the cooked foods Americans eat are in highly processed form. Ninety percent of foods Americans purchase every year are processed foods, and these are primarily in the form of carbohydrates: grains, sugar, fructose, etc.
Not only are these foods largely devoid of nutrition, but fructose and dietary carbohydrates (grains, whose starch break down into the monosaccharide “sugar” glucose) lead to excess body fat, obesity and related health issues. These foods were not consumed, obviously, in ancient times, so even though some of their food may have been cooked, it was still in a primarily unprocessed form. There was no other choice.
There is a growing movement of people who believe eating foods that are concordant with your genetic ancestry can help you avoid many of the diseases associated with our modern diet, including diabetes, heart disease and cancer. Such a diet, sometimes called a Paleo Diet or Caveman Diet, focuses primarily on a wide variety of raw, whole vegetables, fruits, nuts, roots and meat. "Normalizing" your system is the true strength of the so-called caveman diet. As Dr. Loren Cordain, author of The Paleo Diet and one of the world's leading experts on Paleolithic nutrition, states:
"The nutritional qualities of modern processed foods and foods introduced during the Neolithic period are discordant with our ancient and conservative genome. This genetic discordance ultimately manifests itself as various chronic illnesses, which have been dubbed "diseases of civilization."
By severely reducing or eliminating these foods and replacing them with a more healthful cuisine, possessing nutrient qualities more in line with the foods our ancestors consumed, it is possible to improve health and reduce the risk of chronic disease."
Eating an “Ancient” Diet Would be an Improvement for Many
Modern humans are facing a slew of “modern” diseases and conditions that simply weren’t seen – or were only rarely seen – in ancient times. Cancer, heart disease, diabetes, obesity... all of these would apply. Quite simply, we've strayed too far from the foods we are designed to eat, so going back to basics and refocusing your diet on fresh, whole, unprocessed, "real" food can improve just about anyone's health.
You can easily mold your diet around the principles of Paleo eating rather easily by following my recently revised nutrition plan, but generally speaking a "healthy diet" is qualified by the following key factors:
- Unprocessed whole foods
- Often raw or only lightly cooked (ideally, try to eat at least one-third of your food raw, or as much as you can manage)
- Pastured organic or grass-fed, and free from additives and genetically modified ingredients
- Come from high-quality, local sources
- Carbohydrates primarily come from high-nutrient vegetables (except corn and potatoes, which should typically be avoided)