Soy, Isoflavones, Black Cohosh "Helpful" For Menopause Symptoms - ACOG

Soy and isoflavones "may be helpful" for short-term treatment of vasomotor symptoms related to menopause, the American College of Obstetricians & Gynecologists concludes in a new practice bulletin.

Although the mechanisms of action of soy and dietary isoflavones are not fully understood, "they appear to involve binding to the estrogen receptor," ACOG notes. "Given the possibility that these compounds may interact with estrogen, these agents should not be considered free of potential harm in women with estrogen-dependent cancers."

While also finding soy and isoflavone intake over prolonged periods may improve lipoprotein profiles and protect against osteoporosis, the practice bulletin notes "soy in foodstuffs may differ in biological activity from soy and isoflavones in supplements."

"The effects - either beneficial or detrimental - of prolonged intake of supra-dietary levels of soy or isoflavone are unknown," the guidelines caution.

The June bulletin, "Use of Botanicals for Management of Menopausal Symptoms," examines scientific evidence on alternatives to hormone replacement therapies in treating menopausal symptoms and provides recommendations on efficacy and potential adverse effects.

ACOG points to the limited body of available scientific information regarding botanical alternative treatments used for menopause.

"Most of the literature includes in vitro effects, animal models and open, often single-armed or nonrandomized studies," the bulletin says. "The amount and sophistication of studies of most alternative therapies do not meet the current standards for evidence-based recommendations."

Nevertheless, ACOG finds black cohosh may be helpful in short-term treatment for vasomotor symptoms, citing "limited evidence" of a positive effect on sleep disorders, mood disturbance and hot flashes.

"No clinical studies have reported efficacy or safety of black cohosh beyond six months of use," ACOG acknowledges, adding it "should not be confused with blue cohosh, Caulophyllum thalictroides, which has weak nicotine activity and toxic potential."

The benefits of dong quai on vasomotor symptoms "cannot be substantiated based on available evidence," ACOG concludes, warning the botanical may cause excessive bleeding or interactions with other anticoagulants and is potentially photosensitizing, leading to concerns about increased skin cancer risk.

ACOG also finds clinical evidence lacking for use of evening primrose, which produces seeds rich in gamma linolenic acid. "To date, there is only one randomized, double-blind, placebo-controlled study of the use of GLA in the treatment of vasomotor symptoms during menopause....GLA provided no benefits beyond those seen with placebo," the guidelines state.

No published studies have documented an effect of ginseng on libido in menopausal women, ACOG finds. "Ginseng may hold some promise in the treatment of fatigue, depression, immunosuppression and other health problems, but it cannot be recommended as a treatment for menopause."

However, ACOG advises St. John's wort may be helpful for short-term treatment, defined as two years or less, of mild to moderate depression in women.

Turning to the treatment of menstrual disorders, ACOG asserts the hormones in wild and Mexican yam "would not be expected to have any efficacy" due to a lack of bioavailability.

Wild yam extracts are neither estrogenic nor progestational, although some extract products are laced with progesterone, the bulletin says. "Oral ingestion does not produce serum levels. There are no published reports demonstrating the efficacy of wild yam cream."

Although no published studies have investigated the role of clinical monitoring in patients using alternative therapies, ACOG cautions: "Estrogens compounded by an alternative therapy pharmacy may produce varying serum estradiol levels in women or increased estrogen bioactivity without detectable changes in circulating estradiol. Risks of excessive levels include hepatic effects and increased risk of deep vein thrombosis."

Research on herbals and women's health is the focus of a National Institutes of Health-funded botanical center. The University of Illinois-Chicago is examining 10 botanicals, including the effectiveness of red clover and black cohosh in reducing severity and frequency of hot flashes (¹ (Also see "Red Yeast Rice Safety Advantage Over Rx Statins Cited By UCLA Researcher" - Pink Sheet, 2 Oct, 2000.)).