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June 3, 2003 -- Two popular alternatives for calming severe hot flashes don't work -- that's the word from two new studies.
For women weighing their options, it's a puzzler -- especially on the heels of last week's news that combination hormone therapy puts women at risk for dementia.
Women are wondering: What is safe relief for hot flashes? WebMD got opinions from leading experts, plus a roundup of the latest evidence on soy and plant estrogens -- called phytoestrogens.
A few animal studies and some studies on women have suggested that soy may help prevent hot flashes, writes lead researcher Mauro Penotti, MD, with the University of Milan, in the journal Fertility and Sterility.
Soy has indeed seemed promising:
New Soy Information
Penotti's study involved 62 women who were having at least seven hot flashes a day -- what's considered "severe" hot flashes. The women took either a soy supplement -- consisting of 72 mg of soy-derived isoflavones -- or a placebo. Isoflavones have estrogen-like effects. The women also kept a diary of their hot flashes.
At the end of six months, both groups of women had a 40% reduction in hot flashes -- the soy supplements provided no more benefit than the placebo.
Phytoestrogens for Hot Flashes
In the second study, Eini Nikander, MD, with Finland's Helsinki University Central Hospital, studied 56 menopausal women who were being treated for breast cancer. Breast cancer treatment often causes hot flashes. However, hormone replacement therapy (HRT) is rarely used in these women because the hormones may promote a new breast cancer.
The women took either a phytoestrogen (soy) supplement or a placebo for three months. Then they switched treatments for the next three months.
In the end, they found no difference in hot flashes or other menopausal symptoms between the placebo and soy supplement groups, reports Nikander in the current issue of Obstetrics & Gynecology.
Both groups of women had 15% reductions in menopausal symptoms -- but no change in hot flashes. Also, quality of life, including mood, were not improved, says Nikander
What Should Women Do?
For mild hot flashes: Soy is considered a "weak estrogen," so the studies' findings are not surprising, says John Thorp, MD, an ob-gyn at the University of North Carolina in Chapel Hill. For some women with mild hot flashes, "even a weak estrogen might be of benefit," he tells WebMD.
For harsher hot flashes: JoAnn Manson, MD, principle investigator of the Women's Health Initiative, advises that for moderate to severe hot flashes "hormone therapy is still most the effective treatment -- short-term use with the lowest effective dose is the most viable option." She is also chief of preventive medicine at Brigham and Women's Hospital in Boston.
"We try to taper off after one to two years," says Manson. "It is still a reasonable option, but with the caveat that it should be used short-term only. Breast cancer risk begins at three- to four-years duration."
Antidepressants like Paxil and Effexor have also been shown to help relieve hot flashes -- good news for women who cannot take short-term hormone therapy because of breast cancer risk, or for women who have hot flashes from taking the drug tamoxifen for breast cancer, Manson adds.
Holistic Approach
Janet Pregler, MD, director of the Iris Cantor - UCLA Women's Health Center, urges women to take a holistic look at their menopausal symptoms.
"This whole issue of Asian women having fewer hot flashes, less breast cancer -- what about their lifestyle? There's a lot of good evidence that menopausal symptoms are lifestyle-related. When Asian women emigrate to the U.S., if they adopt a more Western diet and lifestyle, their risks of breast cancer and hot flashes increase," Pregler tells WebMD.
She encourages menopausal women to make lifestyle changes -- quit smoking, get more exercise, don't drink alcohol, eat a plant-based diet, including more soy.
"Soy has a positive effect on cholesterol -- it lowers total cholesterol and bad LDL cholesterol, and that's been proven to the point that the FDA allows soy product manufacturers to indicate that soy lowers cholesterol," Pregler says. "There really is no downside to getting more soy."
SOURCES: Obstetrics & Gynecology, June 2003. Fertility and Sterility, May 2003. John Thorp, MD, ob-gyn, University of North Carolina, Chapel Hill. JoAnn Manson, MD, principle investigator, Women's Health Initiative. Janet Pregler, MD, director, Iris Cantor - UCLA Women's Health Center.