Publication outlines rhodiola adulteration and misidentification issues
The program, which is a cooperative effort of the American Botanical Council, the American Herbal Pharmacopoeia and the National Center for Natural Products Research at the University of Mississippi, now has more than 30 publications on botanical adulteration. The goal is to identify which herbs are most commonly adulterated, what they are being adulterated with, and to direct readers to validated lab methods to look for these adulterants.
Mark Blumenthal, founder and executive director of ABC, said rhodiola appears to be growing in popularity, though up to the minute figures are lacking. According to information supplied by ABC, retail sales for rhodiola dietary supplements in the US were $2.6 million in the natural food store channel, where rhodiola supplements ranked 36th. Rhodiola appears to be more accepted in the mainstream outlets (food stores, drug stores, etc.) where it ranked 28th, bringing in more than $10 million in 2016.
Rhodiola is an adaptogenic herb that has been used for mood support and anti anxiety benefits. The main history of use of the botanical, which is native to the northern and higher altitude regions of the Northern Hemisphere, comes from European herbal traditions. It does have some history of use in TCM, but is not one of that tradition’s mainstay herbs, Blumenthal said.
“Most of the evidence for the adaptogenic properties of Rhodiola rosea is based on a series of clinical trials conducted on the world’s leading clinically tested R. rosea proprietary extract produced by the Swedish Herbal Institute in Goteborg, Sweden, as well as studies in the former USSR on various rhodiola preparations,” Blumenthal said.
Adulteration -- intentional or otherwise
The adulteration of rhodiola could be one in which accidental, as opposed to economic, adulteration could play a big role, said Roy Upton, executive director of AHP. Several species have gone under the same generic name of ‘rhodiola,’ and in at least one case the action of the species are similar, leading to their interchangeability in some TCM preparations.
“ R. rosea was the first commercial product introduced to the American health food industry, though other species had been used by Chinese herbalists prior to that. After growing in popularity, other species began entering the market, most notably R. crenulata. R. rosea and R. crenulata are the two dominant species in trade today, though other species may sporadically find their way into trade. Marketers of rhodiola products either knowingly or unknowingly label most rhodiola species as R. rosea even if R. crenulata or another species is used. Herbs of Commerce, the formally recognized source of common names for botanicals, assigned the Standard Common Name of rhodiola for R. rosea, R. algida, and R. kirilowii and interestingly and inconsistently assigned the Latin binomial Rhodiola crenulata as the Standard Common Name for that species,” Upton said.
Blumenthal said that the bulletin is not intended to pass muster on the validity of multispecies preparations of rhodiola supplements. Such formulations could have their place in the market, but to be compliant with US law, they must be labeled as such.
“In commerce, especially in the US and developed countries, such substitution cannot be legally done unless the label states the actual species,” he said.
ABC member publication
The Botanical Adulterants documents are free to all comers. ABC did also announce this past week a publication available only to members, that being an online version of The Identification of Medicinal Plants: A Handbook of the Morphology of Botanicals in Commerce, a manual that addresses the macroscopic assessment of 124 medicinal plants used in North America and Europe.
The book was originally co-published in 2006 by ABC with the Missouri Botanical Garden in St. Louis. It was written by Wendy Applequist, PhD, associate curator at the Missouri Botanical Garden’s William L. Brown Center, and illustrated with botanically accurate black-and-white line drawings by artist Barbara Alongi.
Accurate identification of the correct genus and species of botanical raw materials is the first step in quality control of botanical preparations. While several methods of identification are addressed in the introduction — including macroscopic taxonomic identification, microscopy of plant cells, chemical analysis of plant constituents, and molecular analysis of the plant’s DNA — it is Applequist’s opinion that macroscopic analysis of whole plants and plant parts (when possible) is often a preferred method of species identification because it is quick and relatively inexpensive. Blumenthal said the manual could be a highly valuable resource for companies dealing directly with wildcrafted botanicals.