Soy isoflavones as a first-line approach to the treatment of vasomotor symptoms of menopause

The link between higher uptake of isoflavones and a reduced frequency of menopause-related hot flushes were first described in 1992 based on a lower incidence of hot flushes in countries with high dietary soy intake¹. Since then, a number of clinical trials with different sources of isoflavones, including soy and red clover, have been performed, and in almost all studies with an appropriate design the outcome was in favour of isoflavone supplementation². A detailed risk assessment³ revealed that a number of data in humans do not confirm the alleged adverse effect resulting from possible interaction between isoflavones and the hormone-sensitive tissues of the mammary glands, uterus and thyroid. Safety was demonstrated by long-term intake of 150 mg of isoflavones per day, which lasted at least three years. It was also found that a high intake of isoflavones prevented the occurrence of breast cancer^4-7. Clinical findings indicate potential benefits of exposure to isoflavones during breast cancer treatment with tamoxifen or anastrozole.