Study clouds evidence on soy and menopause

Middle-aged women may find some relief from hot flashes and other menopause problems with soy supplements, according to Chinese researchers.

They found daily supplements of soy germ isoflavones reduced the sudden sweats more than inactive placebo pills after six months.

But a U.S. expert wasn’t convinced by the results, which run counter to other published studies.

“The majority of them are showing no benefit,” said William W. Wong, a nutrition researcher at Baylor College of Medicine in Houston who wasn’t involved in the new work.

The new study, published in the journal Menopause, is based on 90 Chinese women. A third of them received placebo pills made of starch, while the rest took soy germ isoflavones, either 84 or 126 milligrams a day.

They all kept diaries of their hot flashes and filled out questionnaires about various problems tied to menopause, including hot flashes, sweating, insomnia, tiredness and headache.

At six months, their Kupperman scores - a measure of symptom severity that ranges from 0 to 63 - had dropped by more than 40 percent from an initial value of about 25 in the soy groups.

Conclusions: A daily supplement of 84 or 126 mg soy germ isoflavones may improve menopausal symptoms, although neither dose was found to affect lipid profiles in early postmenopausal Chinese women after 24 weeks of treatment. The favorable effects are unlikely to be associated with female hormones.
The North American Menopause Society

The number of hot flashes also fell from about 20 a week to less than 10.

While the same pattern was seen in the placebo group, it was less pronounced. Their symptom score dropped by 29 percent and the number of hot flashes by 35 percent, according to Dr. Yan-bin Ye of Sun Yat-sen University in Guangzhou.

When symptoms appear in menopause, many women look to the natural world for help. Of the many options available to women in perimenopause and menopause, we classify soy as a menopause “superfood.” Not only have we proven soy effective for reducing frequency and severity of hot flashes in thousands of cases at our clinic, but we have also seen that it is safe and easy to use for nearly everyone, especially as part of a combined approach using healthy lifestyle choices and gentle endocrine support.

So let’s review why soy is an especially healthy choice in menopause and touch on a few points you may not have heard about yet.

Soy isoflavones for menopause symptoms

The soybean (Glycine max) belongs to the legume family, whose members include peas, beans, and peanuts, as well as clovers and alders. Legumes feature phytonutrients that lend some unique benefits to women in menopause. The soybean in especially rich in isoflavones, the most widely studied class of phytonutrients. Of the three main types of soybean isoflavones, the ones found most effective for menopause symptoms relief are genistein and daidzein. Recently a third isoflavone, glycitein, is also being studied to determine its health benefits.

In addition to the healing power of isoflavones, soy is also high in antioxidants, omega-3’s, and protein. Plus, it’s low on the glycemic index.

The work was supported by Frutarom Netherlands, which also donated the supplements.

Wong cautioned that the new study was small and that the women involved only had few hot flashes. He said it was “hard to believe” that soy would have an effect on these women.

In one of his own studies, Wong found no effect on soy germ isoflavones among women who took the supplements for two years.

The standard drug treatment for stubborn menopause symptoms is hormone replacement therapy. But doctors and women have become increasingly wary of that option because of serious side effects such as increased risk for heart attack, stroke and breast cancer.

Health Benefits of Soy

In General:
*  Due to the recent information about prescription hormone therapy, natural phytoestrogens are very popular and commonly used to combat menopause symptoms such as hot flashes and night sweats.

*  Soy beans and other legumes contain isoflavones and are an important source of dietary phytoestrogens.

*  Soy protein and soy isoflavones are not the same thing.  Therefore, for optimal benefit of the soy isoflavone, it is important to ascertain the isoflavone content of any particular soy product or food chosen. 

*  Soy based compounds must be absorbed in sufficient quantities before they can have any effect in the body, which can cause the effectiveness of various products to differ.
Disease Prevention:
*  A number of studies have demonstrated the effectiveness of soy enriched diets on risk factors for breast cancer, cardiovascular disease and osteoporosis, as well as helping to combat some of the unpleasant symptoms of the menopause.

Breast Cancer:
*  Recently in the news, a fermented soy bean paste called miso was linked to a substantial decrease in the risk of breast cancer among Japanese women.  Soy foods contain isoflavones, but could not be linked, by themselves, with breast cancer risk reduction. The main difference between miso soup and other soy foods consumed by the Japanese is the fermentation process.

Menopause Symptoms:
*  Several studies have shown that women who consume large amounts of soy-based phytoestrogens have fewer menopausal complaints.

*  Twelve studies using soy or soy extracts were evaluated. Soy appeared to have a ‘modest’ benefit in reducing hot flashes.

*  As with all natural approaches, you should also allow sufficient time for the treatment to take effect, generally in the range of 4 to 12 weeks.

Bone Health:
*  A recent study showed that post-menopausal Japanese women who consumed higher amounts of soy isoflavones had a higher bone density.

Cardiovascular Health:
*  The FDA has stamped their approval of soy dietary supplementation. They state that 25 grams of soy per day with a prudent diet may reduce the risk of heart disease.

*  The FDA did not make clear whether it was specifically the soy protein, the isoflavones, or a combination of both that is responsible for this benefit. 

“It is something they need to gauge, is it worth the risk?” Wong told Reuters Health.

He generally recommends exercise and an active lifestyle to women who feel bothered by menopause.

Soy supplements also have side effects such as nausea, bloating, and constipation, according to the National Institutes of Health. A month’s supply costs about $12, while a month of hormone tablets runs between $40 and $60.

Wong said that in Asia, women tend to think of menopause problems as a natural part of life - not a medical problem.

“There is a major cultural difference in how we deal with menopause symptoms,” he mused.

The new study didn’t find significant hormone changes in women who took soy supplements, and Wong said the compounds are probably safe for women.

“Consuming soy is not bad for them,” Wong noted, “but it might be a waste of money if you don’t see any benefit.”

SOURCE: Menopause, online January 24, 2012.


Soy germ isoflavones improve menopausal symptoms but have no effect on blood lipids in early postmenopausal Chinese women: a randomized placebo-controlled trial

Ye, Yan-bin MD; Wang, Zi-lian MD; Zhuo, Shu-yu MD; Lu, Wei MPH; Liao, Hui-fang MPH; Verbruggen, Marian A. PhD; Fang, Shi MD; Mai, Hai-yan MD; Chen, Yu-ming PhD; Su, Yi-xiang MD
doi: 10.1097/gme.0b013e31823dbeda

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