Nearly 20 internationally renowned experts from prestigious institutions in the United States and Europe, including Harvard Medical School and the Karolinska University Hospital, recently gathered in Milan, Italy, to discuss the latest research on isoflavones. Found primarily in soybeans and red clover, isoflavones have been the subject of rigorous investigation during the past two decades. While evidence suggests isoflavones exert a number of health benefits, there have been some questions regarding their safety in recent years. The two-day meeting, organized by the Council for Responsible Nutrition (CRN-USA), gathered leading researchers from around the world to examine the current state of the science on isoflavones.
The first day of the meeting focused on research involving isoflavones and breast cancer, while the second day focused on evidence regarding the ability of isoflavones to alleviate menopausal symptoms. Collectively, the information presented made a strong case for concluding that isoflavones are safe for breast cancer patients and women at high risk of developing this disease—two questions which have recently been debated within the scientific community.
“According to the science presented at this meeting, isoflavones do not have an effect on breast cell proliferation or breast tissue density, which are two well-established biomarkers of breast cancer risk,” said Mark Messina, Ph.D., a well-respected soy isoflavone researcher. “In fact, epidemiologic data presented at the meeting showed that exposure to isoflavone-rich soyfoods may improve the prognosis of breast cancer patients. Further, new findings strongly indicated that certain results from some animal studies that have raised concern about the impact of isoflavones on breast cancer are not applicable to humans.”
Douglas MacKay, N.D., vice president, scientific and regulatory affairs, CRN, also attended the meeting and was encouraged by the science surrounding isoflavones and menopausal symptoms.
“As a licensed naturopathic doctor, one of the most common questions that I received from my adult female patients was how to manage symptoms of menopause naturally, without the use of hormone therapy,” said Dr. MacKay. “I often found that isoflavone supplementation improved symptoms in menopausal women experiencing hot flashes.”
In fact, a recently completed systematic review and meta-analysis presented on the second day of the international meeting concluded that isoflavones significantly alleviate hot flash frequency and severity with an overall improvement of about 50 percent. Since survey data indicate that 70 percent of women with bothersome hot flashes would be quite pleased to experience a 50 percent reduction in symptoms, it was concluded that isoflavones represent a viable alternative to estrogen therapy. Finally, long-term clinical data indicated that isoflavones do not adversely affect thyroid function in healthy women or women with subclinical hypothyroidism.
“The purpose of this meeting was to have a scientifically-based discussion on isoflavones. The researchers at this meeting walked away in unanimous agreement that isoflavones are safe and effective,” said Dr. Messina.
It is expected that much of the information presented at the meeting will be submitted for publication in a scientific or medical journal by the end of the summer.