A Kefir A Day Just Might Keep The Doctor Away


What if eating a serving or two of a given food every day could help boost immunity against common infections, reduce the risk of developing stomach ulcers, skin disorders and maybe even colon cancer? Buttermilk, cheese, kefir, yogurt and tofu may just deliver that kind of payload. The benefits of these "functional foods" are still under study, but dozens of small trials in people suggest they might help promote health in a variety of ways.

Of course, consumption of these products dates back thousands of years. "We've known for centuries that they may help keep a balance between bacteria that is very adaptable and helps with immune function and bacteria that is harmful," says Linda Duffy, associate professor of pediatrics and epidemiology at the State University of New York's at Buffalo. Scientists have found yogurt and kefir, a liquid fermented dairy product, contain such organisms as lactobacillus and bifido-bacteria. These "friendly bacteria" create an acidic environment that thwarts the growth of harmful bacteria in the intestines and possibly elsewhere, including the vagina and the skin.

And it's best to get this healthful bacteria from food rather than "probiotic"dietary supplements, Duffy advises, because supplements are less subject to government regulation than drugs. "Our concern with the probiotic dietary supplements is that we don't know the source of the bacteria, the purification, the quality or how much is really viable in the product," she says. "I'd want to make sure that they're not contaminated. And we don't know how much you should take."

For now, findings suggest a serving a day of yogurt, kefir or other foods that help boost levels of healthful bacteria won't cause harm and is probably a good idea for most people. As Duffy notes, "there's enough evidence from studies and some very small clinical studies to suggest there may be major public-health benefits from consuming cultured food products." For those who don't like these foods or can't tolerate them, there's this tip: Studies from around the world suggest diets rich in vegetables and fruit also boost growth of these healthful bacteria. "If you eat a lot of meat, you may not have as much healthy bacteria," Duffy says.

Good food sources of friendly bacteria and the nutrients to help them thrive include:

Buttermilk: Yes, it's an acquired taste, but its nutrients raise acidity and promote growth of healthful bacteria. Read labels carefully, however, to search for brands that are lowest in fat.

Cheese: Among those that seem to provide the best nutrients for healthful bacteria are edam, gouda, blue cheese, Roquefort, Shropshire and cottage cheese.

Kefir: Sometimes dubbed the champagne of yogurts, kefir is not actually a yogurt, but a fermented milk product that resembles a milkshake. Find it in the diary case at health-food stores and specialty groceries. Like yogurt, it provides both healthful bacteria and the right nutrients to promote their growth in the body.

Soy: Tofu, a fermented bean curd product, and other soy products seem to be especially good at fostering growth of friendly bacteria in the intestine.

Yogurt: The more acidic it tastes, the better, because acidity signals a higher concentration of healthful bacteria. Fresh, unsweetened is best, but even frozen delivers a little beneficial bacteria, plus it's got the right stuff to help friendly bacteria thrive in the body.