You (and Your Brain) are What You Eat

By Andrew Weil, M.D.

We know that what you eat, and don't eat, can affect your health. But is it possible, as the White Rabbit advised Alice, to "feed your head"? Is there such a thing as brain food? I'm convinced there is. The evidence for some foods, such as fish, is stronger than for others, like turmeric and brightly colored vegetables. But none of those foods is bad for you, and they certainly won't make you any less smart.

The reason fish is so good for the brain is the so-called omega-3 fatty acids it contains. Oily fish, like salmon, sardines, mackerel, herring, bluefish and black cod, are the best sources of those special fats. One of the omega-3s--DHA--is the main constituent of cell membranes in the brain, and a deficiency of it can weaken the brain's architecture and leave it vulnerable to disease.

Diets associated with longevity and good health, like the Mediterranean and traditional Japanese diets, are high in omega-3 fatty acids from fish. The North American diet is not. I have long recommended that people in the U.S. eat more fish--at least two servings a week--but I have been concerned lately about reports of increasing levels of mercury, PCBS and other contaminants in certain fish species. In my diet I stick to sardines, herring, Alaskan black cod and Alaskan sockeye salmon. All sockeye (red) salmon are wild--fish farmers haven't yet been able to domesticate them--and since those fish are less carnivorous than other types of salmon, they have lower levels of the environmental contaminants that accumulate as you work your way up the food chain. Canned sockeye, available in most supermarkets, is a perfectly good source of omega-3s.

But for some people it may be easier and safer to rely on fish-oil supplements. The best are distilled and certified to be free of mercury and other toxins. Some are flavored, and some even taste good--or at least a lot better than the cod-liver oil I was forced to take as a kid. One product I recommend is Antarctic krill oil, made from the tiny crustaceans that abound in southern seas and are consumed in great quantities by whales and other marine mammals. Krill oil is red from carotenoid pigments, which have high antioxidant activity, and it doesn't cause those fishy burps. A good starting dose of fish oil of any kind is 1g a day. Higher doses, up to 10g a day, have been used, with varying results, to treat such diverse conditions as depression, attention deficit disorder, bipolar disorder and even autism.

Vegetarian sources of omega-3 fatty acids, such as walnuts, flax and hemp, are good additions to the diet but not so reliable as fish. They supply a short-chain compound (ALA) that the body must convert to long-chain DHA, and the efficiency of that conversion can vary. Some people don't do it well, and those eating mainstream diets top-heavy in the omega-6 fatty acids found in processed food and prepared meals are at a disadvantage because omega-6s interfere with the conversion of ALA to DHA. For vegetarians and vegans, there is one nonfish source of long-chain omega-3s: supplements made from algae. (Algae is the source of the omega-3s that fish store in their fat)

I'm not aware of any brain foods that have as much scientific evidence behind them as fish and fish oil. But I would keep an eye on turmeric, the yellow spice that is a major ingredient in American mustard and Indian curries. A relative of ginger, turmeric comes from the underground stem of a tropical plant and is being carefully studied for its medicinal effects. It is a powerful anti-inflammatory agent that has anticancer properties and may offer significant protection against Alzheimer's disease. Alzheimer's begins as an inflammatory process in the brain. Anti-inflammatory agents like ibuprofen reduce the risk of Alzheimer's, and so do turmeric and its most studied component, curcumin. India has the world's lowest rate of Alzheimer's, and some experts think that daily consumption of turmeric is a contributing factor.

Finally, in addition to all the other reasons to eat fruits and vegetables, there are some that relate to the brain. The pigments that account for the varied colors of vegetables and fruits have antioxidant properties that offer significant protection against cancer and other chronic diseases, as well as protection from a range of environmental toxins, including pesticides. Toxic injury to the brain is almost certainly the cause of Parkinson's disease, and probably amyotrophic lateral sclerosis (Lou Gehrig's disease). For that reason alone, it's a good idea to eat every day from as many parts of the color spectrum as you can. It's also a good idea to take a daily multivitamin-multimineral supplement that provides the right doses and forms of the key antioxidants: vitamins C and E, mixed carotenoids and selenium.

A good diet is certainly not the only way to protect and enhance brain health. Regularly exercising the mind and not smoking are also important. But food choices do count. So eat your vegetables, think about your daily dose of omega-3s, and consider flavoring more of your food with turmeric.

Andrew Weil is clinical professor of medicine at the University of Arizona, where he founded the program in integrative medicine