Caution Urged on Soy-Based Menopause Remedies

Remember what I said about natural medicine being held to a higher standard than traditional medicine? Here we have a researcher saying that we are not fully informed on how soy works in the human body and so we need to be careful with its use. A little reality check for the author–a large chunk of the drugs listed in the PDR have “mechanism of action unknown” on them and yet we throw these about like candy. But soy, with literally centuries of use, needs to be approached with caution. I would have to add that using soy supplements that have the percieved active constituents concentrated is probably not the best way to approach the use of soy in a healthy lifestyle.

British Endocrine Societies’ annual meeting in Harrogate, Yorkshire Apr 08 – So little is known about how plant oestrogens act on the human body that sales of soy supplements as a “natural” alternative to hormone replacement therapy (HRT) must be questioned, a researcher reported on Tuesday at British Endocrine Societies’ annual meeting in Harrogate, Yorkshire. Soy has been widely promoted as a natural alternative to HRT. Soy contains genistein, a plant oestrogen that has similar but weaker effects as the oestrogen found in women. But Dr. Saffron Whitehead, reader in reproductive physiology at St. George’s Hospital Medical School, London, said new studies on human cells have shown that genistein and other phyto-oestrogens may also block the enzymes that make these hormones. This could explain why the incidence of breast cancer, which in many cases is dependent on oestrogen, is about two thirds lower amongst Japanese and Chinese women who consume diets rich in soy compared with women living in England, she told her colleagues. Dr. Whitehead’s team examined the effects of phyto-oestrogens on human ovarian cells obtained during procedures for in vitro fertilization. The results showed that several phyto-oestrogens, including genistein, inhibited the conversion of androgen to oestrogen. The researchers believe this could be significant in postmenopausal women because as ovaries cease to function in menopause, oestrogen converted from androgen becomes the only source of oestrogen. “This finding is potentially important to the phyto-oestrogen story,” Dr. Whitehead said in a statement. “We really don’t know how phyto-oestrogens act in the human body. They could be weak oestrogen mimics, oestrogen blockers or enzyme inhibitors. “If they do stop the natural production of oestrogens, we should consider whether soy supplements be sold as a natural alternative to HRT.”

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