Straight Talk About Herbal Supplements

New Web site discusses their safety, effectiveness

By Jennifer Thomas
HealthScoutNews Reporter

TUESDAY, Jan. 21 (HealthScoutNews) -- If you have high blood pressure, did you know you probably shouldn't take ginseng?

Or that St. John's wort can interfere with chemotherapy?

Or that garlic capsules and gingko biloba can hinder blood coagulation, a potentially major problem if you had to undergo surgery?

A new Web site created by experts at Memorial Sloan-Kettering Cancer Center in New York City provides up-to-date information on the safety and efficacy of 135 of the most popular herbal remedies and dietary supplements, from bee pollen to shark cartilage and skullcap to milk thistle.

Each entry includes a summary and a critique of all the known medical studies on the supplement, as well as a link to the original research on the National Institutes of Health's Medline.

In the past decade, use of alternative treatments has skyrocketed, says Barrie Cassileth, chief of integrative medicine at Memorial Sloan-Kettering, who started the site. "But until now there was no easy access to current, comprehensive information about these agents," she adds.

Research is under way around the globe to scientifically document the effects of hundreds of herbs and other dietary supplements.

Some studies have proven that certain natural substances do have benefits, though in nearly all cases research is mixed. The element zinc, for example, has shown promise in lessening the duration of a cold by making it difficult for the rhinovirus to replicate. And some research shows St. Johns wort can help ease depression.

But that means the converse is also true -- herbs can be dangerous.

"Herbs are powerful, biologically active products that do have important biological effects," Cassileth says. "Those effects can be useful at some times and harmful under other circumstances."

"Herbs should not be used in a casual fashion because they are serious medicines," she adds.

For instance, ginseng can cause low blood sugar in diabetics. And valerian and kava can lessen the effectiveness of prescription drugs by interfering with the liver's ability to process the medicines, Cassileth says.

Another thing to keep in mind: While much is known about the effects of herbs on the body, much more is not known.

Dietary supplements are not regulated by the U.S. Food and Drug Administration, or any government agency. That means the potency in one bottle of St. Johns wort, for example, can -- and often does -- vary dramatically from that in another bottle, Cassileth says.

And you can't even be sure you're getting St. Johns Wort.

"Anybody can put anything on a bottle and put it on a health food store shelf," she says. "Some of the herbal remedies have virtually none of what is assumed to be the active ingredient, some have much higher levels and some are contaminated with other substances."

On the new Web site, the 135 supplements are listed in alphabetical order by scientific name. The common name is below it. (Acanthopanax Senticosus is better known as ginseng. Allium Sativun is better known as garlic).

Each entry includes the brand names the herb is sold under, its purported uses, its chemical properties, and what's known about how the herb works on the body.

Each entry also includes a summary and a critique of all the known published medical studies, instances of adverse reactions, and warnings about potentially dangerous drug interactions.

Each critique is fully cited and linked to Medline, so that doctors or patients can retrieve the original research and read further if they wish.

The site will be continually updated, Cassileth says. In a few weeks, Cassileth and her colleagues are planning to launch a second Web site that will be less technical and more easily understood by patients.

Dr. David Rosenthal, past president of the American Cancer Society, endorses the Web site.

"This resource is an invaluable tool for both doctors and patients looking for comprehensive information about dietary supplements," Rosenthal says.

More information

To visit the Sloan-Kettering site, click here. For more on herbal medicine, visit the National Institutes of Health.

SOURCES: Barrie Cassileth, Ph.D., chief, integrative medicine, Memorial Sloan-Kettering Cancer Center, New York City

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