DNA Barcoding May Curb Adulteration of Natural Health Products
As dietary supplement sales continue to rise, the authenticity of natural health products is likely to remain at center stage. In addition to concerns about willful "spiking" of dietary supplements with pharmaceutical drugs, dietary supplements may have substitutions, contaminants, and fillers not indicated on the label. Herbal products, particularly those market for weight loss, body building, and sexual performance, appear to be more prone to adulteration than other types of dietary supplements. An emerging technology, known as DNA barcoding, is being developed as an accessible and inexpensive way to verify the identity of botanical medicines.
The process of DNA barcoding uses DNA sequence information in order to identify animal and plant species of varying origin and form. One group of investigators was able identify up to 75% of the natural health products tested, with success rates up to 88% in certain cases. They also determined that half of the samples labelled as Korean ginseng were actually American ginseng. A substitution of one for the other could have significant effects on both the safety and efficacy of ginseng use, as these are two species with different medicinal properties and potential for toxicity.
Identification by DNA barcoding has applications beyond the dietary supplement industry to the food industry as a whole. In a European study, researchers demonstrated that 25% of fish sampled from supermarkets were mislabeled. Similar to the United States, the European Union has strict food labeling standards that are often difficult to enforce.
However, the technology is not without limitations. Since DNA barcoding relies upon well-defined DNA sequences, it is often difficult to distinguish between samples at the species level. This limits its practical usage in differentiating between medicinal herbs within the same family.
DNA barcoding stands poised to emerge as a leading technology in the prevention of adulteration of herbal medicines, among other technologies currently in use by cGMP-compliant dietary supplement manufacturers and third-party testing and certification services. However, it may be a while yet before the technology becomes reliable enough to be used in order to demonstrate compliance with FDA regulations of natural health products.
Lauren J. Wallace, Stephanie M.A.L. Boilard, Shannon H.C. Eagle, Jennifer L. Spall, Shadi Shokralla, Mehrdad Hajibabaei. DNA barcodes for everyday life: Routine authentication of Natural Health Products. Food Research International, 2012; doi: 10.1016/j.foodres.2012.07.048
Miller et al. Smoke, mirrors, and mislabeled cod: poor transparency in the European seafood industry. Frontiers in Ecology and the Environment, 2010; 100422073144024 doi: 10.1890/090212
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Last Updated: 04 Nov 13