When we think of degenerative diseases we think of deterioration of the body, we don’t think of deterioration of the mind. But the brain is no more, or no less, vulnerable to the ravages of our diet. The components of what we eat don’t just circulate below the neck. We consume five pounds of food per day on average—140,000 pounds of food in a lifetime. That is a lot of food matter circulating throughout our bodies.
Each form of life, every species, is programmed for behavior that will sustain it rather than destroy it. There are no doubt sound evolutionary reasons for carnivorous animals to be fierce and aggressive and non-carnivorous animals to be peaceful and sociable.
To put it succinctly, the matter we chose to eat, matters, when it comes to our gray matter.