Eat Your Way to Good Health

Evolutionary science tells us that hominid brains appear to have remained fairly constant in size for a long period from some 1.8 million years ago until about 600,000 years ago. But then, from 600,000 to 150,000 years before the present, fossils show that the cranial capacity of our ancestors skyrocketed. Brain mass peaked at about 1,440 grams (3.17 pounds) during the time of Neanderthals. Since then brain mass has declined to the 1,300 grams (2.87 pounds) that is typical today. The decline in size of the brain corresponds to the shrinking of our bodies since the time of the Neanderthals. There is some evidence that our brains may still be shrinking and that they may have shrunk by as much as 5% over the last ten thousand years. This begs the questions: 'Why did our brains stop expanding?' and 'Why have they reversed their growth trend in recent times?'

This very recent period of brain shrinkage coincides with a major dietary change; it was around this period that cereals and grain (grass seed) along with meat from domesticated livestock came to dominate human diets. Cereals and grains and the meat from cows, chickens, and pigs, still the foundation of our western diet today, may be responsible for the huge expansion in our population, but are they really the best foods for optimal function?

Multiple studies suggest that nearly everywhere this transition to cereals and domesticated livestock has occurred, health has declined. Human lifespans during early agrarian times were rarely more than thirty years. In contrast, the lifespan of the woodland ape has always been around sixty years. If we assume that humans in the forest may have lived easily as long if not longer, then one might argue that a forest lifestyle and diet may be a more natural and perhaps more suitable way for humans to thrive.

Few would argue that there is an increasing problem with the food we are eating in our modern world. And even though longevity has increased over the last few centuries and we increasingly outlive the earlier challenges that would have previously put us in the ground, are we healthier as we live longer? Could we eat healthier today to live more optimally?

Much evidence supports the idea that a more natural diet may be a more beneficial option. Lymphocyte production, and hence resistance to illness, is boosted by consuming the nutrients that occur in optimal proportions and quantities in uncooked vegetables. There are also a huge number of cases in which raw food, particularly fruit and vegetable juices, has seemingly cured a wide range of illnesses. There are clinics, foundations, and institutions throughout the world that offer therapies based on “LIVING NUTRITION.” Such diets are much closer to our ancestral diets than the chips, pies, and cookies that fill most of our supermarket shelves.

The diet of our ancestors most likely consisted of insects, fruit, and some meat, all of it BIOLOGICALLY ACTIVE material. Our cousins the chimpanzees eat meat, but only a relatively small amount. Despite their skill in capturing live prey, chimpanzees still obtain about 94 percent of their annual diet from plants, primarily ripe fruits. Primate biochemistry is largely based on plants, and a plant-based diet is what hominids were likely eating as well during their evolutionary development. Early humans living in the forest probably ate a lot of fruit, and likely only scavenged meat when the rare opportunity presented itself.

The teeth of early human fossils show that they primarily ate fruit. Primates, given a choice, will select fruit in preference to any other food. Fruit is a rich, nutritious, and easily digestible food. If it is available, this is what all the great apes prefer to eat. Our ancestors were likely not vegetarians as they included a variety of foods such as insects, bird eggs, small mammals, and scavenged meat in their diet. But the majority of their diet must have been fruit.

Humans are by nature frugivorous. There has been much study and even more speculation about what sort of diet our teeth and guts are best designed for. From the type of dentition, gut length, and toxicity of foods like meat, a very strong case can be built for Homo sapiens being designed to eat and process a largely fruit-based diet. The brain’s requirements for food and the gut’s requirements for energy, the optimal acid/alkali balance, and the structure of the intestines all point to a frugivorous diet.

Big brains and a diet high in fruit appear to go together. There is a view held by some that meat, and particularly the high protein content of meat, was somehow responsible for the enlargement of our brains. The assumed “higher-quality” meat diet theoretically allowed more energy to fuel the brain with a shorter small intestine. This reasoning is flawed. Meat is supposed to be easy to digest and to be a high-energy food, but fruit is much more easily digested and provides more readily available energy. Fruit fits the brain-gut energy equation: the shorter gut, the more ease of digestion, the lower the toxicity, and the smaller the teeth. Fruit is easy to assimilate, and the nutrition it provides is in a form that needs very little conversion to the real requirement of the brain - glucose. High-quality fruit is low in toxicity and provides all the fuel the brain needs. Meat, conversely, is more difficult to digest, particularly without cooking, and then to turn protein into sugar requires yet more energy. So meat as an energy food doesn’t make as much sense as fruit that is full of fruit sugars that are easily assimilated and take little conversion.

Is your brain going to grow if you eat more fruit? Not really. But if your health improves, and eating more fruit gets you back swinging in the trees, then who really cares what the scientists have to say!