THURSDAY, July 8, 2004 (HealthDayNews) -- High dietary levels of natural plant estrogens found in soy don't appear to increase the risk of breast or uterine cancer, says a Wake Forest University Baptist Medical Center study.
"This is convincing evidence that at dietary levels, the estrogens found in soy do not stimulate cell growth and other markers for cancer risk," veterinarian and lead researcher Charles E. Wood said in a prepared statement.
"The findings should be especially interesting to women at high risk for breast cancer who take soy products," he said.
There's debate among experts about whether high levels of dietary soy -- which contain estrogen-like compounds called isoflavones or phytoestrogens -- are safe for postmenopausal women.
The most common form of hormone therapy, estrogen plus progestin, has been linked to an increased risk of breast cancer in postmenopausal women.
"Evidence from observational studies in women indicates that soy intake may help prevent breast cancer. But there has still been reluctance to conduct research studies in women because of concerns that isoflavones may stimulate breast cell growth and increase the risk of breast cancer," Wood said.
The study, which was conducted on monkeys, appears in the current issue of the Journal of Clinical Endocrinology & Metabolism.
The American College of Obstetricians and Gynecologists has more about herbal products for menopause.