Yogurt: The Curds and Whey to Health?

by Food and Drug Administration (FDA)

When Little Miss Muffet sat on her tuffet for a quick snack that fateful day, she never got to finish what was perhaps the 18th century version of one of today's popular dairy snacks — curds and whey.

We know it as yogurt.

Yogurt is an ancient food, but it remained relatively obscure in the United States until about 20 years ago. Americans ate an average of 4.1 pounds of yogurt per person in 1990, four times as much as in 1970, according to the U.S. Department of Agriculture. Europeans eat even more yogurt than we do, as much as 17 pounds per person annually, according to the National Yogurt Association.

Why the surge for curds? Yogurt carries a reputation — scientifically deserved or not — for being a "health food."

"Certainly it's very clear that yogurt is exceptionally nutritious and a great source of calcium," says Mona Sutnick, Ph.D., a registered dietitian and spokeswoman for the American Dietetic Association.

"The other neat thing about yogurt," Sutnick adds, "is that you can substitute it for things that are high in fat." Low-fat or nonfat yogurt can step in for mayonnaise, sour cream, and cream cheese to make recipes healthier, Sutnick says.

Yogurt has mythic appeal as well.

In 1910, Russian researcher Ilya Metchnikoff reported that Bulgarian peasants, whose diets included a great deal of yogurt, lived an average of 87 years. Although the claim has since been refuted, scientists have for years explored whether there's an elixir of life — or any other healthful benefits — to be found in yogurt.

In addition to the claim of promoting long life, yogurt has been touted by some researchers as a cure for digestive ills, high cholesterol levels, vaginal infections, and even cancerous tumors in animals.

The focus for these health claims is primarily on the bacteria added during yogurt production. The bacteria, Lactobacillus bulgaricus and Streptococcus thermophilus, ferment, or culture, ordinary milk into a tart, creamy gel. The gel contains solids, called curds, and liquid, called whey.

This fermenting process was used as long ago as 2,000 B.C. by Middle Eastern civilizations to preserve milk, and since then yogurt has been a staple in European and Mediterranean diets. In fact, according to the National Yogurt Association, the ancient Assyrian word for yogurt, lebeny, also meant "life."

But does yogurt deserve such praise?

Scientific studies have not convincingly supported many claims about yogurt's healing properties, and FDA won't allow food manufacturers to make unsubstantiated medical or health claims on food product labels.

There are, however, a number of clear nutritional benefits available in Little Miss Muffet's snack.

A Spoonful Helps the Calcium Go Down

The main benefit of yogurt is that, like other dairy products, it's a good source of calcium, vitamins and other minerals.

Yogurt may also be easier to digest than regular milk by those who cannot digest lactose, a sugar in milk products. Many people in the world, including some 40 million Americans, are lactose intolerant. The condition is very common except among people of European ancestry. For the lactose intolerant, dairy products containing significant amounts of lactose cause diarrhea, abdominal cramps, and nausea.

Yogurt is easier to digest because enzymes from the yogurt bacteria break down some of the lactose during the fermentation process. There's also preliminary evidence that once the yogurt's eaten, the bacteria may continue to help break down lactose in the intestinal tract.

As for other claims about yogurt, questions remain.

Few today claim eating yogurt ensures longevity. The Bulgarians, for example, practiced a number of healthy habits besides eating yogurt, so it's impossible to say their passion for curds and whey guaranteed their old age.

But other health claims circulate, fueled primarily by the yogurt industry and sometimes encouraged by scientific studies of yogurt.

Some researchers say yogurt can help manage diarrhea caused by antibiotic therapy by reestablishing the "good" bacteria killed along with the bad during treatment.

"I think the jury's still out on this," says Sutnick. "I am seeing enough research that I would no longer 'pooh-pooh' these things as silly. But I think we need more research before we can be sure.

"If you have diarrhea from antibiotics," she says, "try eating some yogurt. It's certainly nutritious, it can't hurt you, and it might even help."

It's common folklore among women that yogurt cultures can help ward off vaginal yeast infections by countering harmful bacteria.

Doctors don't agree on whether this is so, however. Some cautiously recommend yogurt to their patients; others say it's useless.

"I can't say it definitely worked, but the preliminary data suggest yogurt may be helpful [in preventing yeast infections]," says Eileen Hilton, M.D., an assistant professor at the Albert Einstein College of Medicine in the Bronx, N.Y.

About the Author

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