DNA Testing Finds Contamination Of Many Herbal Dietary Products

A study using DNA barcoding to analyze the plant species found in samples of herbal supplements found that 59 percent were contaminated with plant species not listed on product labels. Worse, more than two thirds of the products tested contained plant species that were substituted for the plants listed on label. A third of the products also contained other species that may be filler or simply contamination. The U.S. study also found in some products plant species that were toxic, had side effects or had negative interactions with other herbs, supplements, or medications. The researchers suggested that the herbal industry use molecular diagnostic tools such as DNA barcoding to authenticate herbal products by testing of raw materials.