Oct. 30, 2000 -- It wouldn't hurt.

Though it won't do the job all by itself, yogurt contains a variety of substances that may strengthen your body's ability to fight disease. First among these come the bacteria that make yogurt out of milk: Lactobacillus bulgaricus and Streptococcus thermophilus. In test-tube experiments, these bacteria appear to stimulate disease-fighting cells. Researchers theorize that they may reduce the amount of nitrite, a cancer-causing chemical, in your body, and crowd out harmful bacteria in your intestines. They also think proteins and calcium from the yogurt itself may nourish disease-fighting cells.

A few studies have found that people who eat lots of yogurt (and other fermented milk products) are less likely to suffer from breast cancer and from infectious types of diarrhea. And in animal experiments, yogurt slowed the growth of tumors. The evidence is mixed, though; one study found that people who ate lots of yogurt were more likely to get ovarian cancer. And dairy products can upset the digestion of people who are allergic to them or are lactose intolerant.

Recently a pair of Tufts University researchers published a review of the research on yogurt and the immune system in the April 2000 issue of the American Journal of Clinical Nutrition. They speculated that "increased yogurt consumption, particularly in immunocompromised populations such as the elderly, may enhance the immune response, which would in turn increase resistance to immune-related diseases." But they emphasized that lots more research needs to be done before it's clear what, if any, benefits yogurt provides.

Experiments with yogurt are difficult because the amount of live bacteria varies so much from one batch to another.

While you're waiting for the final word, it probably won't hurt to eat more yogurt. The majority of studies suggest it's quite safe. If you do head for the dairy case, look for brands that contain live bacteria. And eat the yogurt raw. That will give you the best chance of enlisting the microscopic warriors in your own defense.

William Collinge, MPH, PhD, is a teacher, researcher and author in the field of integrative health. He has taught in the School of Public Health at the University of California, Berkeley, and at several other universities. His books include Subtle Energy, The American Holistic Health Association Complete Guide to Alternative Medicine, and Recovering from Chronic Fatigue Syndrome.

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