Man stocks shelves with vitamins at store Genetic tests on dozens of herbal products sold in Canada found most contained contaminants or fillers and cheaper substitutions not listed on labels, a study said Friday. Out of a dozen companies studied for testing on 44 herbal products, only two provided entirely authentic products, the researchers found.
\"Contamination and substitution in herbal products present considerable health risks for consumers,\" said lead author Steven Newmaster, botanical director of the Biodiversity Institute of Ontario.
\"We found contamination in several products with plants that have known toxicity, side effects and/or negatively interact with other herbs, supplements and medications.\"
The researchers tested 44 herbal products sold by the 12 companies for the study published in the BMC Medicine journal.
Newmaster noted that one St. John\'s wort supplement, used for treating depression, contained Senna alexandrina, a plant with laxative properties.
Prolonged use could lead to chronic diarrhea and liver damage.
Several other herbal products contained Parthenium hysterophorus (feverfew), which can cause swelling and numbness in the mouth, oral ulcers and nausea. It also reacts with medications metabolized by the liver.
And one ginkgo product was contaminated with Juglans nigra (black walnut), which poses a risk for persons with nut allergies.
Overall, nearly 60 percent of the herbal tablets or capsules tested contained plant species not listed on the label.
More than 20 percent of the products included fillers such as rice, soybeans and wheat also not identified on packaging -- a concern for people on gluten-free diets or with sensitivities to rice or soy.
And researchers detected substituted ingredients in 32 percent of the samples.
Sales of medicinal herbs have soared in North America over the past decade as aging Americans and Canadians seek out alternative treatments and health products.
More than 1,000 companies worldwide now make more than 29,000 varieties of herbal substances, earning a total $60 billion per year.
Regulatory problems are affecting the consistency and safety of natural health products, said Newmaster.
In Canada, a backlog of license applications has meant thousands of products on store shelves lack a full product license.
Newmaster accused some manufacturers of \"unethical activities,\" though no product or company was mentioned in the study.
Source: AFP