May 5, 1997

Does fighting the battle of the bulge give you the blues_ You're not alone. Oxford University researchers have found a direct correlation between diet and depression.

According to a recent report in the British medical journal The Lancet, the blues may be blamed on low blood levels of tryptophan, a component of food proteins. An essential amino acid, L-tryptophan cannot be manufactured by the body itself, but must be obtained from food. Plentiful in milk and bananas, tryptophan is converted in the body into the neurotransmitter serotonin, which calms nervousness, alleviates depression, helps induce sleep and causes us to feel satisfied. Serotonin deficiency has been shown to be a cause of depression.

The researchers studied 15 women who had suffered from major depression. All had recovered and were not on a drug treatment program. The participants were given either a nutritional amino acid mixture with tryptophan or a placebo. After drinking the tryptophan-free mixture, 10 of the 15 women experienced temporary depressive symptoms. No mood changes were found in the women who drank the tryptophan mixture.

According to the Oxford team, "Even modest changes in serotonin activity of the type produced by dieting could have adverse effects in those vulnerable to clinical depression." To maintain a healthy outlook while dieting, say researchers, cut back on calories and fat, but don't skip meals. Remember: when you feed your body, you're feeding your mind, too.

Tapping into Tryptophan

According to Robert Haas' book Eat Smart, Think Smart, the following low-fat foods are good sources of the essential amino acid L-tryptophan:

spirulina seaweed, roasted pumpkin, skim Milk, dried sunflower seeds , baked potato with skin, tomato soup with skim milk, shredded wheat, raw kelp seaweed, boiled turnip greens, and boiled collards.