More threads by Retired


Study Shows Herbal Supplement Black Cohosh Doesn't Reduce Menopause Symptoms

WebMD Medical News Reviewed By Louise Chang, MD

Monday, December 18, 2006 -- Millions of women have taken black cohosh to reduce hot flasheshot flashes and other menopausemenopause-related symptoms, but the most rigorous study of the herbal supplement ever conducted shows no evidence that it works.

The federally {U.S.A} funded trial was designed to compare black cohosh to other herbal supplements, traditional hormone therapy, and placebo treatment for menopausal symptoms.

Hormone therapy was the only treatment that clearly reduced hot flashes, night sweats, and other related symptoms.

The study appears in the Dec. 19 issue of the journal Annals of Internal Medicine (reference below).

"Our finding that black cohosh did not work will be disappointing news to many women," researcher Katherine M. Newton, PhD, tells WebMD. "It would be nice to find a clearly effective alternative to hormone therapy."

Looking for Alternatives
Most women experience hot flashes and related symptoms around the time of menopause, which typically occurs between ages 45 and 55.

Hormone therapy involving estrogen or estrogen plus progestin is very effective for reducing hot flashes, but concerns about safety have caused millions of women to abandon the treatment.

Those concerns appeared to be bolstered late last week with the news of a dramatic drop in breast cancers among American women.

Although the reason for the drop is not yet clear, many experts speculate that it is related to the decline in hormone use following the 2002 publication of the Women's Health Initiative study, which found an increase in both breast cancers and heart problems among users.

Many symptomatic women turned to black cohosh and other herbal supplements when they stopped taking hormones, but few well-designed clinical trials have been done evaluating the effectiveness of these products.

Studying Treatments for Menopause Symptoms
In an effort to address this, Newton and colleagues with the Seattle-based health care system Group Health Cooperative recruited 351 menopausal and newly postmenopausal women for their study.

The women were between the ages of 45 and 55 when they entered the trial, and all were experiencing at least two menopause-related symptoms a day.

Without knowing which treatment they were getting, all of the women took one of five therapies for a year. The treatments were:

  1. Black cohosh alone (160 milligrams daily)
  2. A combination herbal supplement that included 200 milligrams of black cohosh daily, plus alfalfa, boron, dong quai, ginseng, and other herbal ingredients
  3. A combination herbal supplement that did not include black cohosh but did include recommendations to increase the consumption of soy-based foods
  4. Traditional hormone therapy
  5. Placebo
  6. The researchers found no significant difference in the number of daily hot flasheshot flashes experienced by women on any of the treatments, with the exception of hormone therapy
Women taking herbal supplements had an average of half a hot flash a day less than women taking placebo -- an amount not considered significant. By comparison, the women on hormone therapy had about four fewer hot flashes a day.

What Can You Do?
So what can women who don't want to take hormone therapy do to avoid hot flashes? There is some evidence that certain antidepressants help some. And lifestyle measures can make a big difference, Newton says. These include:

  1. Dressing in layers so that you can take off clothing when you feel a hot flash coming on.
  2. Keeping ice water or a fan nearby.
  3. Sleeping in a cool bedroom.
  4. Avoiding triggers, which may include spicy food, alcohol, or hot beverages.
  5. Women who feel they need hormone therapy should take it in the lowest effective dosage for the shortest time necessary, says Sherry Sherman, PhD, of the National Institute on Aging (NIA).
"It may be that hormone therapy is more risky for some women than for others," she tells WebMD. "We would love to be able to identify those women who can safely take estrogen and those who shouldn't."

Those custom compounded hormones that have been the subject of much recent media attention were not evaluated in the new study.

Bioidentical hormones are being touted by some, including actress and author Suzanne Somers, as being safer alternatives to traditional hormone therapy.

But Sherman says if the hormones are as effective as traditional hormones, they probably carry the same risks.

Sherman is director of clinical aging and reproductive hormone research at NIA.

"Just because you take a drug and don't know the risks doesn't mean those risks don't exist," she says.

Also of interest is this related article:

Black Cohosh Not Always What It Seems

SOURCES: Newton, K.M. Annals of Internal Medicine, Dec. 19, 2006; vol 145: pp 869-879. Katherine M. Newton, PhD, associate director of research, Group Health Center for Health Studies, Seattle. Sherry Sherman, PhD, director, clinical aging and reproductive hormone research, National Institute on Aging, National Institutes of Health, Bethesda, Md.

David Baxter PhD

Late Founder
Mechanism Of Black Cohosh Versus Hot Flashes Revealed

I don't disagree with the article above at all, particularly the warning about not assuming "natural remedy" means "safe and without side-effects".

However, it's not surprising that people find the whole issue of alternative medicine confusing. Here's another article on the same remedy.

Mechanism Of Black Cohosh Versus Hot Flashes Revealed
December 26, 2006
Science Daily

The natural herb black cohosh is commonly used by women to treat menopausal symptoms such as hot flashes, but the molecular mechanisms underlying its action have eluded scientists -- until now.

Researchers at the University of Illinois at Chicago and the National Institutes of Health Center for Botanical Dietary Supplements Research have discovered that black cohosh may act on human opiate receptors, which play a role in regulating a body's temperature.

Z. Jim Wang, assistant professor of pharmacology and pharmaceutics, led the study, which will be published in an upcoming issue of the Journal of Agricultural and Food Chemistry; the paper is currently available on the journal's web site.

Opiate receptors are chemical sensors that respond to opiates like morphine and endorphins, Wang said. Chemical substances with opiate activity bind to the receptors and produce the appropriate response, including the regulation of pain, temperature and appetite.

"We used several extracts of black cohosh and found that elements of the herb could bind to the human 'mu' opiate receptor," Wang said. "The opiate receptor system affects several aspects of female reproductive neuroendocrinology, such as the levels of sex hormones and neurotransmitters that are important for temperature regulation."

Black cohosh (known as both Actaea racemosa and Cimicifuga racemosa) is a member of the buttercup family. A perennial plant, it is native to North America. It has been used by Native Americans to treat malaise, gynecological disorders, kidney ailments, malaria, rheumatism and sore throat, as well as colds, cough, constipation, hives and backaches, and to induce lactation.

Women experience a variety of symptoms of menopause, but the hot flash is the most common. Although the exact mechanism of the hot flash is unclear, estrogen withdrawal during menopause clearly plays an important role, Wang said. It is assumed that declining estrogen concentrations may change the levels of brain chemicals called neurotransmitters.

As a result, the thermoregulatory center located in the hypothalamus functions irregularly, which leads to inappropriate peripheral vasodilatation that causes hot flashes.

"The hypothalamic thermostat setting can be controlled directly or indirectly by the opiate system," Wang said.

Wang said this is the first time black cohosh has been linked to the activity of the opiate receptors. The ethanol extract used in this study, he said, is currently being used in a phase II clinical trial conducted by researchers from the UIC/NIH Center for Botanical Dietary Supplements Research.

Note: This story has been adapted from a news release issued by University of Illinois at Chicago.


Re: Black Cohosh Ineffective for Hot Flashes

Here's another perspective on the topic for your consideration:

Black cohosh won't cool hot flashes

NEW YORK (Reuters) -- Women with hot flashes related to menopause are unlikely to find relief with the herbal supplement black cohosh -- alone or in combination with other herbal therapies -- according to a report released this week.

"We were disappointed by the findings," said Dr. Katherine M. Newton in a news release, "because many women want an alternative to hormone therapy and many have assumed that black cohosh is a safe, effective choice."

Newton, the principal investigator of the study which appears in the Annals of Internal Medicine this week, and colleagues from the Group Health Cooperative in Seattle studied 351 menopausal women, between the ages of 45 and 55, experiencing at least two hot flashes or night sweats each day.

The women were randomly assigned to one of five treatment groups: 160 milligrams of black cohosh daily; a multi-botanical supplement containing 200 milligrams black cohosh and 9 other herbal ingredients including alfalfa, pomegranate and Siberian ginseng; a multi-botanical supplement plus increased soy consumption; hormone therapy (estrogen with or without progestin); or inactive 'placebo' capsules.

After 3, 6, and 12 months, black cohosh was no better than placebo in reducing the frequency or severity of hot flashes or night sweats, the team found. The same was true for the other herbal products.

As expected, women who received hormone therapy had significantly fewer hot flashes and night sweats than women given placebo. However, "While hormone therapy is still the most effective treatment for hot flashes, recent studies have shown that it poses serious risks," Newton noted, such as the risk of heart disease, stroke, and some types of cancer.

The "good news" from this study, according to Dr. Carol M. Mangione of the University of California, Los Angeles, is that women in the placebo group experienced about a 30 percent reduction in the severity and frequency of hot flashes and night sweats during the yearlong study.

This should help reassure women that with time these bothersome symptoms will ease up on their own, Mangione writes in a commentary accompanying the study.

Mangione also notes that it's too soon to throw in the towel on the potential benefits of soy on the symptoms of menopause. Because most women in the soy group did not increase their soy intake to the target level, "this trial probably was not an adequate test of dietary soy" for treatment of menopausal symptoms, she writes.

It is "easy and probably safe" for women experiencing hot flashes and night sweats to increase their intake of soy and see whether it helps, Mangione adds.


David Baxter PhD

Late Founder
Herbs Found Ineffective for Menopause Symptoms
December 26, 2006

Black cohosh and other botanicals widely used to relieve the hot flashes and night sweats of menopause are no more effective than a placebo, according to a new study.

Researchers tested 351 women over one year, dividing them into five groups. The first took 160 milligrams of black cohosh daily, the second took black cohosh in combination with a group of other botanicals including pomegranate, chaste tree and ginseng. A third group took the multibotanical regimen and received counseling that recommended two soy food servings per day to provide 12 to 20 grams of soy protein. The fourth received daily doses of estrogen with or without progestin, and the fifth took an inactive placebo.

Neither the researchers nor the women themselves, who kept diaries of their symptom severity, knew which group they were in.

The study, published in the Dec. 19 issue of The Annals of Internal Medicine, found that hormone treatment reduced night sweats by an average of one per night and hot flashes by an average of three per day, but that none of the botanical treatments differed from the placebo.

“We don’t want our message to be that all women should rush back to hormone treatment,” said Katherine M. Newton, the lead author and associate director for research at the Group Health Center for Health Studies in Seattle. “Women should remember that the menopause transition is a normal event and that their symptoms will pass with time. Those who are very troubled by their symptoms should discuss treatment with their health care providers.”

Women assigned to the hormone treatment reported more breast pain and menstrual disorders than those who received a placebo, but there were few severe adverse effects in any of the groups.
What i see as interesting is that study about black cohosh binding to the MU opiate receptor. I wonder if its a agonist or antagonist. id guess the latter.
Replying is not possible. This forum is only available as an archive.