May 25 2009
Check Out the Big Brain on Cro-Magnon – Fish Oil and Intelligence
Fish is brain food, quite literally. Our nervous systems are composed partly of the same polyunsaturated fats (most of
which are docosahexaenoic acid; DHA and arachidonic acid; AA) found in fish. It is no coincidence, then, that the omega-3 fatty acids (DHA and EPA) you keep hearing about are essential nutrients for the development and intellectual growth of the human brain.
Check this out. The modern human brain is over three times as large as the brain of our earliest hominid ancestors – who walked upright on the savannas of Africa some 4 million years ago. Archaeologists have observed that as we evolved from these small ape-like ancestors, we did so in costal regions, exploiting marine resources – fish.
In essence, in order to grow our giant brains, we needed littoral marine and lacustrine food sources – chicken of the sea, if you will. In fact, researchers propose that land mammals did not provide the essential fatty acids necessary to build bigger, stronger brains. So, only those of our ancestors found at the land/water interface got the necessary nutrition to bulk up their brains.
And not only are our brains big, they’re hungry. Of all the nutrients that a mother provides the fetus in her womb, the brain of the fetus consumes a full 70% of this energy. That’s one greedy organ! And what’s the preferred fuel for this gluttony? The same fats we introduced earlier – DHA and AA. Interestingly, the fetus will consume so much of these that the mother usually becomes depleted in these fats (and this depletion is linked with postpartum depression).
And not only are these fats important for babies, these same fats are necessary for sustaining normal adult brain function! Let’s go back over 100,000 years ago when the first members of our species are found on the Cape of South Africa at places like Blombos Cave. Here we find anatomically modern humans exploiting a marine setting, exhibiting novel behavioral characteristics. These people were using sophisticated hunting and fishing technologies; they were using new symbols and art – all of these behaviors fed by their big brains and increased intelligence. Of course this intelligence was primarily devoted to the food quest.
Obviously, there is not a direct cause-and-effect relationship between fish consumption and intelligence. Otherwise, grizzly bears taking advantage of annual salmon migrations would have developed the cure for cancer by now. Nevertheless, a high quality diet including prodigious amounts of EFA’s was important in our evolution and remains important today.
