Curcuminoid Content and Safety-Related Markers of Quality of Turmeric Dietary Supplements Sold in an Urban Retail Marketplace in the United States.

Abstract

SCOPE: Turmeric is a top selling dietary supplement (DS) in the United States with rapidly expanding usage. Therefore, turmeric DS formulations available for sale in an urban US retail marketplace were analyzed, and point of sale information was related to measures of quality relevant to safety.

METHODS AND RESULTS: Eighty-seven unique turmeric DS were identified; a majority (94%) contained turmeric-derived curcuminoid extracts (TD-CE), which were combined with other bioactives in 47% of products, including piperine (24%), an additive that could alter the metabolism of concurrent medications. While curcuminoid content was within 80% of anticipated for a majority of products analyzed (n = 35), curcuminoid composition (% curcumin) did not meet USP criteria for TD-CE in 59% and was suggestive of possible unlabeled use of synthetic curcumin in some. Lead content was associated with inclusion of turmeric root and exceeded USP limits in one product. Residues of toxic class 1 or 2 solvents, which are not needed for TD-CE isolation, were present in 71% of products, although quantified levels were within USP-specified limits.

CONCLUSION: Assessment of turmeric DS quality at point of sale is difficult for consumers and may best be managed in partnership with knowledgeable health care professionals.