Soy Isoflavones: An Effective Alternative to Hormone Replacement Therapy?

Soy isoflavones have been suggested as a replacement for traditional Hormone Replacement Therapy (HRT). In menopausal women, ovulation is disrupted by a decline in the ovarian follicles’ sensitivity to two hormones that stimulate ovulation, follicle stimulating hormone and luteinizing hormone (FSH and LH, respectively). The ovaries produce less estrogen, and the decline in LH eventually causes a decline in the production of progesterone. Estrogen is the primary hormone that stimulates the development of secondary female sexual characteristics, and progesterone is the hormone that prepares the mucus membrane of the uterus to receive the ovum. Eventually, ovaries fail completely to produce estrogen, and women derive their estrogen entirely from the adrenal glands and from fat cells. HRT attempts to replace the lost hormones. There is some research to suggest that soy isoflavones may do the same job as traditional HRT.

Soy isoflavones are thought to be useful in the treatment of menopausal and post- menopausal women because in the Orient, where consumption of soy is very high, menopausal symptoms were so rare that the Japanese do not even have a word for menopause. In theory, soy isoflavones are useful in the treatment of menopausal women because they perform an estrogen receptor

binding function; this binding function benefits women whose bodies are producing reduced estrogen levels during menopause.

Soy isoflavones can also help prevent osteoporosis. Studies indicate that the isoflavone ipriflavone can increase bone mass, although not in the same chemical path as estrogen. Soy isoflavones have also been proven effective in the treatment of hot flashes among post menopausal women. Soy isoflavones have the additional advantage of being non-toxic, while the research on HRT remains inconclusive. Studies have indicated that HRT, while improving quality of life for many women, can actually lower life expectancy. Some HRTs increase the risk of estrogen-related cancers, including breast and uterine cancer; HRTs can also cause breast sensitivity, vomiting, and yeast infections. None of these harmful side affects have thus far been observed among women taking soy isoflavones. A 1996 National Cancer Institute report judged that Genistein, the principal soy isoflavone compound most often used in the treatment of menopausal women, was non-toxic and non-carcinogenic.

There are dissenting voices, however, about the safety of soy isoflavones. An article submitted to the FDA recently maintains that the claims about the presence and use of soy in the diet of Asians is historically inaccurate, that the soybean known to the Asians for centuries is radically different than the soy

used now as the base for soy isoflavones, and that the medical testing in support of soy isoflavones has been flawed and lacks a true scientific and scholarly consensus. The health risks of soy consumption, in the view of the article’s author, greatly outweigh any supposed benefits. The question, then, of the utility of soy isoflavones for treating menopausal symptoms, cannot yet be considered settled.

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