In another boost to the reputation of soy, researchers claim to have found a link between higher soy intake and reduced breast cancer risk.
　　 Women without breast cancer have roughly 60 percent higher levels of isoflavones -- compounds found primarily in soy -- than do women with the disease, say scientists at Vanderbilt University and the Cancer Research Center of Hawaii.

This translates statistically into a reduction of breast cancer risk by as much as 50 percent among those with the highest levels of isoflavones, says study co-author Dr. Wei Zheng, a Vanderbilt professor.

"This is one of the first studies in humans that involves an association [between soy intake and reduced breast cancer risk]," Zheng says. "It is too early to say whether it's causal, however. You have to be cautious."

For their study, the researchers measured isoflavone levels in the urine of 120 women from Shanghai, China, to determine how much soy they consumed. Half of the women had been diagnosed with breast cancer and half were cancer free.

"The average level of isoflavones was on average 60 percent lower [in those women with a cancer diagnosis]," Zheng says.

The women's isoflavone levels were consistent with what they reported they ate, he says. Those with higher levels said they consumed more soy products, like tofu and beans.

Lee-Jane Lu, a University of Texas professor who also studies the effects of isoflavones on breast cancer, says "it's conceivable" that differences exist in isoflavone levels among those with and without breast cancer.

"It is an area a lot of us are pursuing, trying to find if this is going to prevent cancer or not," Lu says.

Soy has been touted in recent years as a healthy food source that reduces risk for a variety of diseases. The American Heart Association, for instance, last month recommended adding soy protein to daily diets as a way to help reduce high cholesterol levels.

Some studies have indicated that to best enjoy the benefits of soy, you must start taking it at puberty and that waiting to start in middle age is too late. But Zheng disagrees.

"I don't think the evidence is strong enough to say you have to start at puberty, but certainly it would be good to start as early as possible," he says.

Zheng presented his findings yesterday in Hawaii at the International Chemical Congress of the Pacific Basin Societies, which meets every five years. Results also appeared earlier this year in the journal Cancer Epidemiology, Biomarkers and Prevention.

(From HealthScout)