Compound found in soybeans effective in reducing hot flashes in menopausal women

Researchers at Beth Israel Deaconess Medical Centre (BIDMC) have found that a compound in soybeans is effective in reducing the frequency and severity of hot flashes in menopausal women.

The findings, which appear in the January issue of Menopause, showed a 52 percent reduction in the number of hot flashes among patients who consumed a soy supplement without evidence of negative side effects.

'What we are trying to find is a safe and effective alternative to hormone therapy,' says senior author investigator George Blackburn, MD, PhD, Department of Medicine, Obstetrics and Gynaecology, and Surgery at BIDMC, Harvard Medical School. 'Our study found that patients who consumed the soy supplement showed a reduction in the number of hot flashes.' Blackburn explains that while hormone therapy yields the best results in treating hot flashes, its long-term use could increase the risk of certain medical disorders such as coronary heart disease or stroke. About 75 percent of all menopausal women are affected by hot flashes which are marked by the sudden, intense, feeling of heat caused by a decline in oestrogen levels. With evidence that hot flashes are often uncommon in countries where a lot of soybeans are consumed, the research team at BIDMC decided to test a compound found abundantly in soy germ, in the form of a daidzein-rich isoflavone-aglycone supplement (DRI). Isoflavones are one of several classes of phytooestrogens that exert both oestrogenic and antioestrogenic properties.

'The chemical structure of this compound is very similar to that of our own oestrogen, allowing it to act as a regulatory mechanism if the body's natural levels decrease,' explains Hope Ricciotti, MD, Obstetrics and Gynaecology at BIDMC.

Researchers studied 147 menopausal women who were divided into three groups and instructed to take one soft-gel DRI capsule a day. They tested two different DRI concentrations, 40 mg or 60 mg, and compared them to a group taking a placebo. After 12 weeks, hot flash frequency was reduced by 52 percent in the 40 mg DRI group and 51 percent in the 60 mg DRI group compared with 39 percent in the placebo group. The effects of isoflavones can be complex because of the many varieties of soy foods and the different methods of preparation. This study used a standardised, concentrated isoflavone ingredient called AglyMax made by extracting the isoflavones from soy germ fermented with Koji fungus.

'What we found was that the degree of improvement in women taking the DRI supplement was similar to that of alternative therapies such as a serotonin inhibitor but without their negative side effects,' says Ricciotti who adds that the patients saw an improvement in quality of life.

In addition to Blackburn and Ricciotti, the research team included Lalita Khaodhiar, MD, Department of Medicine, BIDMC; Linglin Li, MS, Department of Surgery, BIDMC; Weijun Pan, MD, Department of Surgery, BIDMC; Mary Schickel, Obstetrics and Gynaecology, BIDMC; Jinrong Zhou, PhD, Department of Surgery, BIDMC.

This study was funded by a research grant from Nichimo Co Ltd, Tokyo, Japan.