Herbs and supplements are a popular form of complementary and alternative products used by millions of Americans to promote health or treat a variety of self-diagnosed perceived maladies. They are widely available without a prescription. For many of these products, there is little evidence of their use and information provided by sellers of these products is often lacking, insufficient, or incorrect.
This week, in an early online version of the American Journal of Medicine, researchers studied the state of online information available for top selling herbal products.
In their study, researchers searched Google for information regarding the top 10 herbal products sold in the US using general and shopping searches. According to a recent nationwide survey, the 10 most commonly used herbs in the US include cranberry, Echinacea, flaxseed oil, ginseng, ginkgo biloba, garlic, green tea, grape seed extract, saw palmetto, and soy. Study authors included an additional three herbal products with safety concerns: black cohosh, kava, and St. John’s wort. The top 50 websites found on a search for each product were examined for clinical claims, warnings, and other safety information.
A total of 1179 websites were examined with less than eight percent providing information regarding adverse effects, drug interactions, or other safety information. Only 10.5 percent recommend discussing use of the herb with a healthcare professional. Sites that sold products (retail sites) were less likely to recommend consulting with a healthcare professional compared to sites that only provided information. Less than three percent cited any scientific literature to back their claims. Fourteen percent of retail websites included information that violated Food and Drug Administration criteria by making claims about diagnosing, treating, preventing, or curing a disease. These claims were more common for sites selling soy, black cohosh, and green tea extract with 20 to 38 percent of claims violating FDA criteria.
Study authors concluded that key safety information is lacking for most online sources of herbal information.