Soy has many benefits, but caveat emptor

Here's a way to use your bean: Eat more soy to boost your health.

Health experts generally agree that soy, a plant food that comes from soybeans, can be a great source of protein, fiber, vitamins and minerals.

"It is easy to add soy to your diet," said Marlo Mittler, a child and adolescent nutritionist at Cohen Children's Medical Center in New Hyde Park. "You can try soy milk, edamame , veggie burgers made with soy, soy cheese, soy nuts. Or, make smoothies and add tofu for protein or cook stir-fry with tofu" (also known as soybean curd).

But not every food that features soy is necessarily good for you, and the full extent of its health benefits and risks is not yet fully understood. Here's what you should know about soy:

A NUTRITIONAL STAR

"Soy is considered healthy because it is a great source of protein as it provides all nine of the essential amino acids in the amounts needed for human health," Mittler said. "This makes it the perfect protein, especially for vegetarians who would not otherwise get this in their diet."

Soy foods also contain such nutrients as fiber, B vitamins and omega-3 fatty acids, she added.

But you do need to know what you're eating. "Soy supplements and foods made from isolated soy protein may not offer the same balance of nutrients as foods made from the whole soybean," said Pam Birkenfeld, a registered dietitian with Nassau University Medical Center in East Meadow. "Also, many soy bars and drinks have a lot of added sugar, so it is a good idea to read nutrition labels."

CHOLESTEROL BUSTER?

Evidence suggests that soy may reduce "bad" cholesterol, Birkenfeld said, referring to low-density lipoprotein (LDL) cholesterol.

The U.S. Food and Drug Administration recommends that people consume 25 grams of soy protein a day to boost their heart health, although that may not be easy: A soy burger patty contains just 10 grams, and 8 ounces of soy milk has from 3 to 10 grams.

Still, there are plenty of ways to add soy to your diet, even if you don't like soy milk or veggie burgers. "Tofu can be added to any sauteed dish or added to ground beef or turkey to make a loaf," Birkenfeld said. And tempeh, a fermented soy product, "can be used in the same way. Edamames can be added to any vegetable dish to increase color, texture and nutrition."

Soy might fight cancer.

"More research is needed to draw firm conclusions about soy and reducing the risk of certain cancers, although some data suggests soy intake may have particular benefits for reducing the risk of breast, prostate and colon cancer," Birkenfeld said.

'PLANT ESTROGENS'

The health effect of soy comes from what are called soy isoflavones -- components of soy known as "plant estrogens" because their chemical structure is very similar to estrogen, the hormone that humans make, explained Josephine Connolly-Schoonen, a registered dietitian and clinical assistant professor at Stony Brook University Medical Center. "The fact that these components are similar to chemicals produced by humans allow for health benefits when these compounds mimic the human varieties," she said.

Soy isoflavones also are available as nutritional supplements.

However, some research has suggested that the estrogen-like effect could be dangerous. Isabell Hance, a registered dietitian at St. Joseph Hospital in Bethpage, warned that women who have breast cancer should be cautious because some research suggests that soy could boost breast cancer cells.

A study in the February issue of Cancer Prevention Research reported that soy supplements did not stem the growth of breast cancer cells any better than placebo pills, and that cancer cells actually increased in younger women who took the soy supplements.

Whether soy consumption comes from food or supplements, though, might matter. Researchers believe that nutrients obtained through supplements do not always have the same effect as nutrients obtained through food, sometimes because the body absorbs them differently.

Women who have breast cancer or are at high risk for the disease "should be careful about using large amounts of soy products and should discuss it with their health care provider," Hance said.

FLASH! (OR NOT . . . )

The scientific jury is still out on whether soy helps women who suffer from menopausal hot flashes.

"Studies showed that with 100 milligrams of soy isoflavones, there was a significant reduction in hot flashes, mood swings and sleep disturbances," Mittler said. It has been shown to reduce the number and intensity of the flashes, she said.

Other research has reported just the opposite.

For most people, eating soy foods is like eating anything else, though some people have trouble digesting soy. But Birkenfeld cautioned that more study needs to be done on whether a diet that's especially high in soy has long-term effects.