A new study found a majority of herbal products contained ingredients that were not listed on the label.
The researchers tested 44 herbal products from 12 companies and found only two stayed totally true to their label, a University of Guelph news release reported.
About 60 percent of the products contained a species of plant that was not mentioned on the label. Twenty percent of the tested herbal products also contained fillers such as rice that were not listed on the container. Thirty-two percent of the samples substituted ingredients.
"Contamination and substitution in herbal products present considerable health risks for consumers," lead author Steven Newmaster, an integrative biology professor and botanical director of the Guelph-based Biodiversity Institute of Ontario (BIO), said.
"We found contamination in several products with plants that have known toxicity, side effects and/or negatively interact with other herbs, supplements and medications," he said.
One product that was labeled as St. John's wort contained a plant with laxative-like qualities. The ingredient, called Senna alexandrina, is not meant to be taken over long periods of time, and doing so can result in health consequences such as liver damage.
A number of other products contained Parthenium hysterophorus (feverfew) without listing it on the label, this plant can cause swelling of the mouth, ulcers, and nausea.
One gingko product contained black walnut, which could cause a serious reaction in someone with a nut allergy.
Using rice, wheat, and other fillers could also put people with allergies at risk.
"It's common practice in natural products to use fillers such as these, which are mixed with the active ingredients. But a consumer has a right to see all of the plant species used in producing a natural product on the list of ingredients," Newmaster said.
Newmaster's team has developed new techniques for sniffing out the true ingredients in herbal products.
"There is a need to protect consumers from the economic and health risks associated with herbal product fraud. Currently there are no standards for authentication of herbal products," Newmaster said.
