NUTRITION AND EVOLUTION
The food we eat is fundamentally important for the evolution of the human brain. In fact, without food that supplies adequate amounts of certain long-chain fatty acids, our brains could not possibly develop. Since food is so common—as well as being universal—we often forget that the available nutrients actually determine how all living forms are able to develop. In this regard, Charles Darwin wrote in The Origin of Species about essential "conditions."
On April 9 we had a fascinating lecture, briefly summarized here, on all these subjects from Michael Crawford, PhD, Director of the Institute of Brain Development and Human Nutrition in London, England and lead author of Nutrition and Evolution.* He contends that food is the driving force of evolution. When life began there was no question of scarcity:
In a lovely picture that he showed of a mother and child, the child’s brain case is the size of the mother’s. However, its hand is tiny compared to hers. We have a unique specialization—brain development. The rhino does not get the food for brain growth.
The brain needs lipid (fat), not protein nor minerals. The brain is 60 percent fat. Its very special kinds of fat are predominantly docasahexanoic acid (DHA) and arachidonic acid, which are the longest-chain essential omega-3 and omega-6 fatty acids respectively. "DHA and arachidonic acid are the main lipids in the brain and in all neural systems. The same in all animals."
How did we evolve our large brains? In contrast to us, the Savannah animals, even our closest relatives, the great apes, have tiny brain-to-body ratios compared to ours.
Dr. Crawford argues "not that man evolved a large brain but rather found an ecological niche with nutrients that allowed the brain to grow at the same rate as the body. The marine food chain provides the nutrients that are vital and essential for the brain. Infants know how to swim, don’t have hair, have a layer of subcutaneous fat, and lose water to keep cool. Savanna animals don’t."
In New Zealand when Dr. Crawford’s first grandson, Oliver, was one and a half months old, his "daughter believing implicitly in her father, dropped the baby into the swimming pool. He opened his eyes, did a sort of breast stroke cum paddle and when he came to the surface he put his head on the side and took a breath."
"Five written languages all developed beside water." When we imagine the great migrations to Polynesia, "people must have been totally comfortable with the marine environment." Dr. Crawford likes "to think of people having tools to build boats rather than for killing animals and people."
In summary, "without DHA and associated trace elements that are protective, cerebral expansion in Homo sapiens was impossible."
Evolution is not stopping. Recent increases in protein consumption have resulted in remarkable increases in height in just one or two generations. We know we can increase our size but no way do we want to follow the example of the huge rhino with its minuscule brain!
We have manipulated and destroyed many of the nutrients that are necessary for the brain, the nervous system, and the heart. "In blood vessels arachidonic acid is major and DHA is proportionately less. The vascular system needs both the (n-3) fatty acids and antioxidants. When both are missing there is lethal damage in experimental animals 100 percent of the time."
"In human fetal development the brain takes up 70 percent of the energy—both calories and oxygen. This is totally unique within the human species. Have to have a darned good pump. The cardiovascular system continues to grow after birth." On the other hand, "the human brain develops mostly before birth and for the first six months." Since the brain is protected within the womb, the effect of altered nutrition is first felt in the growing, unprotected cardiovascular system. "Having seen the rise in mortality from cardiovascular disease this century in so-called westernized countries and seeing the same phenomenon occurring now in developing countries, the real question that we are faced with is: Where are we going from here? What is going to happen to the children born in the next century? We can get an increase in neurological disorders, a decline in intelligence quotient, and an increase in antisocial behavior."
Dr. Crawford has worked in the Queen Elizabeth Hospital for Children and has seen the terrible effects on the children of malnourished mothers. Earlier he and his wife, Sheilagh, worked in East Africa, studied the various primitive tribes, and for years he did highly complex laboratory studies. In the year NOHA was founded he and his wife published What We Eat Today: The Food Manipulators vs. The People warning us of the dangers from the alterations in our food. For thirty years he has been writing and lecturing about the importance of the fragile fatty acids that are essential for our brains, hearts, and vision. He has worked particularly hard to have the "neural fatty-acids," DHA and arachidonic acid, added to infant formulas. They are concentrated in mother’s milk and practically nonexistent in cow’s milk. (Cows don’t have much in the way of brains.) Now, the neural fatty acids are added to formulas in European countries and in the Far East, but not in the United States.
In their newsletter, the International Society for the Study of Fatty Acids and Lipids announced the presentation of the 1995 International Award for Modern Nutrition to Dr. Crawford. "This prize . . . is one of the senior awards in the biomedical sciences. . . . In his acceptance speech, Dr. Crawford stated that he viewed the award not only as a personal tribute, but as acceptance by the scientific community of the central importance of polyunsaturated fatty acids for human health and the intelligence of future generations."
*The Driving Force: Food, Evolution, and the Future, Michael Crawford and David Marsh, William Heinemann, Ltd., Great Britain, 1989, 298 pages, $25.00, ISBN 0-06-039069-7. Paperback edition: Nutrition and Evolution, Keats Publishing, Inc., 29 Pine Street, Box 876, New Canaan, Connecticut 06840-0876, 1995, 298 pages, $15.95, ISBN 0-87983-657-1.
Article from NOHA NEWS, Vol. XXII, No. 3, Summer 1997, pages 1-2.