More Research Is Questioning Safety, Effectiveness of Herbs

Too bad there isn't an herb that cures confusion.

The $4.2 billion herbal-supplement market was rocked in August 2002 by news of a federal investigation into a marketer of the weight-loss product ephedra. But recent evidence suggests that the industry's problems go well beyond that. Indeed, research has found that half of the dozen top-selling herbal supplements are either useless for their marketed purposes or dangerous.

Ginkgo biloba, the second-most popular supplement, did not improve memory in a rigorous study published this month. St. John's wort is no better at treating major depression than a sugar pill, a federal study concluded. An apple a day would do about as well at preventing the common cold as echinacea, according to another recent study. And last week, the antistress supplement kava was banned by Canada amid more signs that it could cause liver damage. The U.S. Food and Drug Administration issued its own warning about kava in March, and Singapore and Germany have banned kava products.

"There's more evidence that calls into question their efficacy than evidence that argues persuasively that these products are effective," says Ron Davis, a member of the American Medical Association's Board of Trustees and its spokesman for dietary-supplement issues.

The dietary industry plays down the recent reports, pointing to previous studies that draw contradictory conclusions and continuing research that it hopes will yield more positive results. "Look, there's always going to be another trial," says John Cardellina, vice president for botanical science at the Council for Responsible Nutrition, a group that represents the industry's interests in Washington. "It's the accumulated weight of evidence that matters."

Much of this information is coming out now because the National Institutes of Health and other federal agencies started to fund the kinds of studies that would put supplements to the test. Once, herbal cures were a small and ignored mom-and-pop business. But after sales took off in the past two decades, the medical establishment took notice.

The NIH has pumped huge amounts of money into nutrition-related research -- a total of $206 million in fiscal 1, the last year for which numbers are available. The Office of Dietary Supplements, which helps coordinate such research, has seen its budget jump to $17 million from less than $1 million in the past five years.

The nation is "just now beginning to reap the reward of an investment that was made a few years ago," says Raymond Woosley, vice president for health sciences at the University of Arizona and a chief critic of the supplement ephedra. "The controlled trials of herbal products are just now beginning to be completed -- and I think we're going to learn what works and what doesn't."

More results are on the way, assessing herbs like ginger, boswellia and green tea. The conclusions could renew calls for Congress and the FDA to further tighten the rules on the industry, which still maintains some powerful friends in Washington. Herbal supplements are part of a broader category of dietary supplements that also includes an array of vitamins and minerals. Unlike prescription drugs, which must be proved effective and safe before they are sold to the public, a dietary supplement generally can only be removed from the market after it's been shown to be harmful.

The herbal market is continuing to grow overall, although certain supplements have fallen out of favor. The industry says its products are safe when used as directed, while the medical establishment says many are worthless, leaving consumers a bit perplexed. While consumers await the results of ongoing research, the AMA and other groups urge people to tell their doctors they are using supplements; the information could help ward off dangerous drug interactions between herbal products and pharmaceuticals.

Conflicting Studies

The ephedra controversy shows how contentious all the conflicting studies can be. Ephedra is under attack because of dozens of heart attacks and strokes in people who have taken ephedra products. The AMA wants it banned. But Metabolife International Inc., the product's leading marketer, cites a study from researchers affiliated with Harvard and Columbia universities that shows "no adverse events and minimal side effects" among patients taking an ephedra-and-caffeine product. Claims to the contrary, including reports of fatalities, are anecdotal "junk science" that is drowning out good science, the company argues.

The university study was far from perfect, says Dr. Woosley. The subjects in that trial were under medical supervision, and those with serious health conditions were screened out, so any unusual effect the supplement had on those already at risk wouldn't have been noticed. Plus the limited size of the study by the time it was over -- 46 people on ephedra and 41 on a placebo -- means it was impossible to find the 1-in-100 or 1-in-1,000 risks that emerge in the large trials drug companies submit to the FDA.