NEW ORLEANS (AP) -- Scientists say there is growing evidence that soybean protein -- commonly found in tofu -- may relieve discomforts women feel during menopause.

Dr. Gregory L. Burke of Bowman Gray School of Medicine in Winston-Salem, North Carolina, outlined the results of an experiment into soy's effects on menopause at the American Heart Associations annual scientific meeting Sunday.

The study involved 43 women between ages 45 and 55 who suffered at least one bout of hot flashes or night sweating daily. For six weeks, they worked 20 grams of powdered soy protein into their diets, mixing it with their orange juice or sprinkling it on their cereal. For another six weeks, they did the same with powered carbohydrate. No one knew until the end of the experiment which they were eating.

The women reported significantly less intense symptoms while using the soy protein, although they occurred just as frequently.

Krause plans another study, involving 240 women, in which larger doses of soy will be tried. Another study, conducted recently at the University of Manchester in England, suggests this can reduce the frequency of hot flashes, as well.

Experts believe the key ingredient of soy protein is phytoestrogen -- the plant form of the female hormone estrogen. Human estrogen is widely used to relieve the effects of menopause, although some women are reluctant to take it because of side effects.

Laboratory studies suggest that soy estrogen acts on the same chemical targets in the body that human estrogen affects, although it is 1,000 times less potent.

Doctors have other reasons to think that soy might be a treatment for menopausal symptoms. One is the rarity of these problems in Asian countries, where the soy bean is common. Indeed, Burke said there is no phrase in Japanese for "hot flash."

Both heart disease and breast cancer are four times more common in the United States as in Japan, and the risk of uterine cancer is 40 percent higher.

Of course, there are many differences between Japanese and U.S. women, including their genetic make up and their tendency to be obese. However, one clear difference is diet, especially the frequency of soy foods rich in phytoestrogen.

Burke said the typical Japanese diet includes 50 milligrams of phytoestrogen a day. In his hot flash study, women took 34 milligrams a day. In the larger study to be conducted, this will increase to 68 milligrams.

If these studies prove health benefits of soy, one challenge will be to fix them in a "more Western-tolerable way," he said, perhaps by using them as tasteless fillers in otherwise familiar foods.

Nevertheless, he said, "It's prudent to recommend that folks consume more soy in their diets."

The heart association's nutrition committee, which draws up widely followed eating guidelines, is not ready to recommend that Americans start eating tofu burgers and drinking soy milk. But it's watching the fast-moving soybean research closely and will change them to include more soy if the findings show that's a good idea.

"I think we are on a pretty fast track here," said Dr. Ronald Krause of the Lawrence Berkeley Laboratory at the University of California, the committee's head.