Most so-called natural health or herbal products contain ingredients not listed on the label and are chock full of cheaper fillers, according to a new study.
University of Guelph researchers, publishing in the open access journal BMC Medicine, used DNA barcoding technology to test 44 herbal products sold by 12 companies.
Of the 12 companies, just two actually provided products as described on their labels and did so without including inexpensive contaminants or fillers.
The most commonly found substance not listed on the label were plant species, discovered in almost 60 percent of products studied. Product substitution occurred in nearly one third of all products and about one fifth of products contained unlisted follers like soybeans and wheat.
Said lead author Steven Newmaster, an integrative biology professor and botanical director of the Guelph-based Biodiversity Institute of Ontario (BIO):
Contamination and substitution in herbal products present considerable health risks for consumers. We found contamination in several products with plants that have known toxicity, side effects and/or negatively interact with other herbs, supplements and medications.
One issue with the unlisted fillers is that they could cause problems for consumers seeking gluten-free products, Newmaster added.
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.
The market for medicinal herbs and plant products is growing at an extraordinary rate, and it is believed to be a $60 billion industry worldwide. A lack of regulatory oversight is hurting consumers, both financially and in terms of their health, say researchers.
This is exacerbated by the absence of any authentication standards.
Source: BMC Medicine