Survey on the Quality of the Top-Selling European and American Botanical Dietary Supplements Containing Boswellic Acids.

In consideration of the increasing popularity of frankincense and the widely published quality problems associated with botanical dietary supplements, a survey was conducted for the first time on the quality of frankincense containing botanical dietary supplements. Six US products representing 78 % of the units sold and 70 % of the market value, and 11 European products representing 30 % of the units sold and 40 % of the market value were tested for their boswellic acid composition profile, label compliance, and claimed health benefits. Special focus was also set on the statements made with regard to the frankincense applied.Only five products out of seventeen disclosed all relevant information for the Boswellia extract, mentioning the species, the part of plant used, and the boswellic acid content. Whereas all products but one claimed to use Boswellia serrata, three products did not mention the resin as the part applied and 10 products did not declare the boswellic acid content. Apart from the different boswellic acid composition determined with a sensitive LC/MS method, 41 % of the products did not comply with the label declaration. Hence, one product from Italy did not contain any of the six characteristic boswellic acids (KBA, AKBA, αBA, βBA, AαBA, AβBA) at all and another US product contained only traces, suggesting the absence of frankincense or the use of Boswellia frereana instead of B. serrata. In another product, the ratios of the individual boswellic acids were different from B. serrata gum resin, indicating the use of another species such as Boswellia sacra or Boswellia carterii. Furthermore, two products revealed different boswellic acid contents from those declared on the label. Further, two products did not declare the use of manipulated Boswellia gum resin extract being enriched in acetyl-11-keto-boswellic acid content reaching up to 66 %. In addition, consumers could be misled by outdated literature or references to in vitro studies performed at dosages that can never be achieved in humans following oral administration.In summary, this survey reveals that in spite of increased regulations on botanical dietary supplements, the problem of mislabeling still exists and needs to be addressed by the manufacturers, so that consumers get greater confidence in the botanical dietary supplements they use.