CORVALLIS - A growing number of busy Americans who used to take vitamins to help balance their nutritional intake are now supplementing their diets with herbs.
And that, experts say, may become a problem.
Herbal supplements, now a multi-billion dollar industry, are not regulated to the same extent as prescription medicines, over-the-counter medicines or vitamins by the Food and Drug Administration, said Wayne Kradjan, dean of the College of Pharmacy at Oregon State University.
While most herbal supplements sold commercially are fairly benign at low doses, some can interact with vitamins or medications to create significant health risks, Kradjan pointed out.
The most popular herbal supplement sold in the U.S., for example, is St. John's wort, used for mild to moderate depression. It also happens to be one of the most highly researched herbs, and studies have shown that it may be useful in moderating mood disorders. There is a growing body of evidence, however, suggesting that St. John's wort also inhibits the effect of a certain family of enzymes that metabolize drugs in the liver.
Persons taking St. John's wort and medication may be at-risk for a variety of medical problems.
"It is exactly those types of drug interactions that concern many physicians and pharmacists," Kradjan said. "Most herbs don't have the body of research supporting their safety because they haven't gone through the FDA approval process that medicines do. And there are few regulations regarding dosage and labeling."
Kradjan said OSU is assuming an active role in training pharmacy students about herbal supplements, and in providing continuing education to working pharmacists. On a recent Sunday, OSU's College of Pharmacy and the university's Linus Pauling Institute hosted an all-day workshop on combining herbal and dietary supplements with prescription drugs. More than 240 Oregon pharmacists, physicians, nurses, dietitians, naturopaths and others attended.
George Constantine, professor emeritus of pharmacy at OSU and author of a new book on herbal remedies, says the lack of regulation needs to be addressed.
"We need either regulation or some kind of standardization," he said. "It's been slow to evolve. The Dietary Supplement Act passed in 1994 helping to regulate the claims some of the manufacturers were making, and the FDA now has some labeling requirements.
"But," he added, "there's still no real bite in the tiger's mouth."
Two years ago, Constantine led a study looking at the labeling of herbal products. The OSU researchers found that only two out of eight St. John's wort products contained what was on the label. Other studies, Constantine says, have had similar results looking at ginseng and gingko biloba.
"If you buy Ibuprofen at a pharmacy, you know how many milligrams of the actual drug are in each capsule," he pointed out. "If you buy an herb like Echinacea or saw palmetto, you don't know if you're receiving a concentrated dosage, or something that's really watered down. And you can't be guaranteed that there is ANY of the herb in there."
Constantine said that most herbs, taken independently, are fairly safe to consume on a short-term basis. There are few research efforts looking at the long-term effects of such products. Such research is hard to conduct and the money simply hasn't been there.
But since herbal supplements have become a multi-billion dollar industry, the major pharmaceutical manufacturers are beginning to take notice, Constantine said.
That may create more pressure to regulate herbs and provide more labeling information. In the meantime, pharmacists are usually the last line of defense when consumers have concerns about interactions between medicines and herbs.
Schools of pharmacy also are trying to adjust.
"We now teach all of our first-year pharmacy students about natural products, focusing on the top 20 in sales," said Kradjan. "And later, when students go through pharmacotherapy courses they learn about all of the common diseases for which therapies are prescribed. Those therapies include prescription and non-prescription drugs, as well as herbal remedies.
"It's a growing area of concern, for our pharmacy students and for the working pharmacists to whom we provide continuing education," Kradjan added.
Consumers who have a question about herbs and possible drug interactions should contact their local pharmacists, the OSU educators recommend.
What people should be careful of, they add, are exaggerated claims - particularly on the Internet. "Some of what you read is absolutely frightening," Constantine said with a shudder. "It is sheer nonsense. Unproven. Unreliable. There are so many claims that are not backed up by any real evidence. That's why some type of oversight or regulation is so important."
The best advice for consumers?
"If you're looking for information on the Internet, try to find sites that back up their claims with research published in a peer-reviewed journal," Constantine said. "And before combining herbs with any medicines, consult a pharmacist."