"One of AHPA's responsible member companies brought this concern [of substitution] to the association's attention a year ago," said Steven Dentali, PhD, AHPA's vice president for scientific and technical affairs.
The AHPA responded by introducing a trade recommendation that manufacturers ensure that they are selling genuine black cohosh - the Actaea racemosa species, otherwise known as Cimicifuga racemosa - and that it is not adulterated with other species such as A. cimicifuga (aka Cimicifuga foetida), Actaea dahurica (C. dahurica) or A. heracleifolia (C. heracleifolia).
The study, published in the Journal of Agricultural and Food Chemistry (Vol. 54, pp. 3242-3253), appears to justify the AHPA's concerns about black cohosh products. The scientists from the Columbia University, the City University of New York and the Chinese Academy of Sciences, tested 11 black cohosh products purchased between 2002 and 2004 from stores in the New York City area.
The scientists, led by Edward Kennelly, tested the products, seven of which were in capsule form and four in tablet form, for key marker compounds. The absence of the compound cimiracemoside C, a product only found in black cohosh, and the presence of cimifugin, a compound found in some Asian Actaea species and not in black cohosh, showed that three of the products did not actually contain black cohosh, and a further product contained a mixture.
"Not only may products containing A. racemosa have different amounts of the extract or key constituents but a newer problem of adulteration with extracts from less expensive Asian species seems to be emerging," wrote the researchers.
The adulteration of products is, according to AHPA, an economic and not a safety issue.
"Manufacturers have a responsibility to know what they are selling and to take adequate steps to ensure that the ingredients in their products match the product labels and vice versa," said the AHPA in a statement.
Since the products were purchased between 2002 and 2004, and before the AHPA's recommendations last year's, Dentali told NutraIngredients-USA.com that he hopes that AHPA member companies are now complying with the association's recommendations, and pointed out that companies could easily verify their products by using AHPA's analytical method.
"AHPA has since identified a practical, appropriate, and inexpensive analytical TLC method that industry can employ to differentiate extracts of black cohosh from closely related Asian species," said Dentali.
Black cohosh is a perennial plant native to North America. According to AHPA's most recent Tonnage Survey of Select North American Wild-Harvested Plants, the herb was the second most harvested plant, with 159 tons from wild sources and 0.2 tons from cultivated sources.