To Your Health:

More Herbs To Ponder

By Nancy DiMarco, Ph.D.

A few weeks ago I began a discussion about herbal supplements, primarily to educate consumers about their usefulness and consider some of the safety issues. Herbs have been around some 5,000 years and were and are used by the Chinese and other eastern cultures for medicinal purposes.

Typically, herbs are plants or parts of plants that are used for their medicinal qualities, taste or aroma. In the United States, herbal medicine has grown faster than any other “alternative” therapy and it is a huge business.

The seven best selling herbal remedies reported by the American Botanical Council in 2002 were: gingko biloba ($151 million in retail sales), St. John’s Wort ($140 million), ginseng ($96 million), garlic ($84 million), echinacea ($70 million), saw palmetto ($32 million) and kava ($17 million).

SAW PALMETTO (Serenoa repens), which is the ripe berries of the American dwarf palm, is primarily used by men for mild to moderate benign prostatic hyperplasia (BPH) or enlarged prostate gland (stages I and II). Its prevents the metabolism of testosterone while acting as an anti-inflammatory agent.

There have been a number of well-controlled clinical trials performed involving more than 3,000 participants, and evidence from these trials indicates that for short-term therapy for mild to moderate benign prostatic hyperplasia, saw palmetto is a “safe and highly desirable option.” The average daily dose recommended for crude berries is 10 grams, twice daily, or for the liquid extract, 1 to 2 milliliters twice daily. It is also available as "soft native extract" that may be taken at 160 mg twice daily or 320 mg, once daily. If you use the "dry normalized extract," the amount recommended is 400 mg, twice daily.

There have been some adverse effects reported, but gastrointestinal disturbance occurs rarely. Taking saw palmetto on an empty stomach may cause nausea. Taking large amounts may cause diarrhea. High blood pressure occurred in 3 percent of patients involved in one clinical study.

KAVA EXTRACT (or Piper methysticum) is made from the dried kava root. It was used traditionally in the South Pacific as a recreational drink. In fact, its name means intoxicating drink. Today it is used to help nervous anxiety, stress, restlessness and as a sedative or sleep aid. It is believed to act is as a muscle relaxant.

Kava also has been studied in a number of controlled clinical trials, but involving fewer participants than with saw palmetto. The results of these studies suggest that kava is effective in decreasing anxiety.
The average recommended dose of a standardized extract (70 percent kavalactones) is 100 mg, two to three times daily. Persons suffering from chronic depression should not take kava, or women during pregnancy or breast-feeding.

Some of the adverse effects reported include mild gastrointestinal disturbances and in rare cases, allergic skin reactions. There also have been several cases of toxic liver damage, including three deaths, associated with kava self-medication.

A year ago, Health Canada (the Canadian’s version of the Food and Drug Administration) issued a stop-sale order of all products containing kava and determined there was no acceptable food use of kava. The FDA followed with an advisory last March. Other health agencies around the world, including those in Germany, the United Kingdom and Switzerland, also received reports of liver toxicity associated with taking kava.

Although liver damage is rare, the FDA believes that consumers need to be aware of this potential health problem. Anyone who has a liver disorder or disease or taking drugs that affect the liver should consult with their doctor before taking kava. It is important that consumers realize that kava can interact with prescription drugs and may cause an increased response to substances that act on the central nervous system, such as alcohol, barbiturates and psychopharmacological drugs.

As mentioned in a previous column, there is no regulation of herbal products in the United States. Herbal products cannot be patented, and therefore, much less rigorous attention is paid to their safety and efficacy.

Because of this lack of regulation, it is difficult to know, at best, whether an herbal product will have the stated pharmacological effect or even if the label provides accurate information. Typically, the potency of the product varies from manufacturer to manufacturer and even from lot to lot by the same manufacturer. The literature is rife with reports that plants are frequently misidentified or even replaced with cheaper or more easily obtained alternatives.

It is particularly important that consumers know that herbal preparations obtained from eastern origins can be contaminated with heavy metals, pesticides and in some cases recognizable drugs.

Adverse reactions to herbal supplements reported to the FDA are most likely underreported because there is not a centralized way to report them. If you have any adverse problems with the use of dietary supplements or herbal products, they should be reported immediately to FDA’s Med Watch program by calling (800) 332-1088 or through the Internet at http://www.fda.gov/medwatch
Caveat Emptor – Let the Buyer Beware!

Dr. Nancy DiMarco is a research professor in the Department of Nutrition and Food Sciences, the nutrition coordinator for the Institute for Women's Health and coordinator of the master's program in Exercise and Sports Nutrition at Texas Woman's University. She can be reached at ndimarco@twu.edu.

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