Herbal Menopause Supplement Often Contains Other Species, DNA Bar Coding Reveals: Scientific American
But controlled trials of this supplement have seen mixed results, sometimes showing it to be effective in relieving hot flashes, sleep disruptions, mood swings and other symptoms whereas other times revealing it to be ineffective. And some case reports even suggest that it can be toxic, damaging the liver.
This messy track record gave Damon Little, a bioinformaticist at The New York Botanical Garden (NYBG), and his colleagues an idea: What if patients—in these trials and out in the community—were not always taking pure, actual black cohosh (Actaea racemosa), but one or more related species? Fortunately, they had just the tool on hand to figure that out: DNA barcoding.
Using this technology, which locates and sequences specific areas of a plant’s genome (specifically, two matK gene nucleotides), they were able to determine that one quarter of commercially available “black cohosh” pills were not the herb at all. Their findings were published this July in the Journal of AOAC International.
“Misidentification and adulteration in black cohosh supplements [has been] known for many years as a matter of concern,” notes Rolf Teschke, an internist at the Teaching Hospital of the Johann Wolfgang Goethe University in Frankfurt and who was not involved in the new research. “The present study confirms—but extends—previous findings.”
Unlike drugs, however, supplements are not required to be tested for safety or efficacy by the U.S. Food and Drug Administration before they hit the market. And testing to make sure the contents match the label are much more lax than it is for pharmaceuticals, opening the opportunity for mislabeling, whether it is accidental or intentional.