Friday, 17 August 2007

An Herbal Menopause Therapy Gets A Closer Look

Publication: USA Today
Author: Rita Rubin

Black snakeroot, squaw root, rattle root, rattle weed, bugwort.
Call it what you will, the herb most commonly known as black cohosh has been used to treat even more conditions than it has names.

Native Americans treated rheumatism, malaise, malaria, colds, constipation and hives with it, to cite a few. In the 19th century, according to the National Institutes of Health’s website, alternative medicine practitioners prescribed it for lung and neurological conditions as well as female reproductive tract problems, such as threatened miscarriage, labor pain and infertility.

More recently, women have been turning to black cohosh supplements for relief of hot flashes and other menopause symptoms. The top-selling brand is Remifemin, made by Schaper & Bruemmer, a German company.

Nothing relieves hot flashes like estrogen, but concerns about its safety have spurred many women to look for “natural” alternatives on the assumption that they are benign. However, based on reports of several dozen hepatitis cases in black cohosh users, Australia and several European countries last year began requiring a warning about liver toxicity on supplement labels.

The regulators in those countries think the risk is extremely low, but the problem is that nothing for the treatment of menopause symptoms, including black cohosh, has been studied as widely as estrogen, whose risks and benefits have been clearly delineated. Complicating matters is the fact that there are about as many different kinds of black cohosh supplements as there are names, because they’re regulated like foods, not drugs, by the Food and Drug Administration.

Different formulas, results

Remifemin itself has changed over the years, says family physician Adriane Fugh-Berman, associate professor in the complementary and alternative medicine master’s program at Georgetown University’s School of Medicine.

“One of the problems with dietary supplements is, unlike drugs, you can change something and keep it under the same label,” she says. “Remifemin used to be a liquid and now it’s a tablet.”

The lack of uniformity in supplements may at least partly explain why the results of clinical trials comparing black cohosh to sugar pills have been mixed. That, and the tiny size of the studies.

The latest trial, a year-long study involving 351 women published last month in the Annals of Internal Medicine, found that 160 milligrams of black cohosh a day was no more effective than a sugar pill.

In an accompanying editorial, UCLA internist Carol Mangione says the well-designed study “makes an important contribution, albeit one that will disappoint women who have been hoping for an effective, safe alternative to estrogen.”

Physician Tieraona Low Dog, director of education for the Program in Integrative Medicine at the University of Arizona Health Sciences, wonders if the scientists who conducted the latest study got the dosage right.

“The dose for black cohosh may be much higher than that used in this trial,” Low Dog says. “Imagine if we did a trial on ibuprofen administering 40 milligrams every six hours for arthritis pain. If it didn’t work any better than placebo, one would conclude it was ineffective. However, the truth would be that the dose was inadequate.”

Fredi Kronenberg, a Columbia University scientist and director of the Richard and Hinda Rosenthal Center for Complementary and Alternative Medicine, notes that the latest study used black cohosh extracted with a different type of alcohol than is used in making Remifemin, and no one knows whether that might boost or inhibit its effectiveness.

In an e-mail statement, Eckehard Liske, a scientist with Remifemin maker Schaper & Bruemmer, said the North American Menopause Society deemed the most recent study of Remifemin, published in 2005, an example of “level one” — the top level — evidence of effectiveness. “Remifemin is a safe and effective intervention for the relief of hot flashes and other vasomotor symptoms associated with menopause,” Liske said.

Treatment has many fans

No question, many women swear by Remifemin and other black cohosh supplements. The latest study found black cohosh to be no more effective than a sugar pill, but that doesn’t mean it didn’t work at all. Kronenberg notes that studies of hot-flash remedies have consistently found a strong placebo effect — by the end of the most recent study, 30% of women taking the sugar pill reported fewer and less severe hot flashes.

Maybe that finding simply reflects the fact that hot flashes subside over time in most women, whether they take anything for them or not. Or maybe, Kronenberg says, it points out that we still have a lot to learn about the physiology of hot flashes and the power of the placebo effect.

“I can’t help but observe that for those who think herbal medicine is passé or ineffective, this study provides further confirmation,” Low Dog says of the latest black cohosh study. “For those who believe herbal medicines are effective — this study is just one more example of how researchers get it wrong. And consumers — well, they just end up confused.”

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