Submitted to: Plant Foods for Human Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/7/2014
Publication Date: 5/23/2014
Publication URL: http://link.springer.com/content/pdf/10.1007%2Fs11130-014-0416-y.pdf
Citation: Lee, J. 2014. Marketplace analysis demonstrates quality control standards needed for black raspberry dietary supplements. Plant Foods for Human Nutrition. 69:161-167.
Interpretive Summary: Controls are needed to ensure that dietary supplements already in the marketplace meet a certain minimum quality, and that they contain their labeled contents (i.e., black raspberry supplements contain a minimum anthocyanin concentration). We purchased all available black raspberry products marketed as supplements for this work (n=19). Each was analyzed for authenticity and anthocyanin concentration. To our surprise, seven out of 19 samples did not contain any black raspberry fruit, and three out of those seven had no detectable anthocyanin. Food sources remain a safer method of obtaining dietary phenolics until dietary supplements become regulated similar to foods in the US, in a manner that promotes authenticity and discourages adulteration. This project was partially funded by a Specialty Crop Research Initiative grant from USDA-National Institute of Food and Agriculture (NIFA).
Technical Abstract: There is currently no standard for the minimum anthocyanin concentration a black raspberry dietary supplement must contain for legal sale in the US. All consumer available black raspberry products (n=19), packaged as dietary supplements or otherwise prepared (freeze-dried whole and pre-ground powders), were purchased and analyzed for their anthocyanin composition and concentration. Seven of the 19 samples contained no anthocyanins from black raspberry fruit, while three of those seven (without black raspberry fruit) had no anthocyanins of any kind. There was a wide range of anthocyanin concentration within the remaining products (18.1-2904.8 mg/100g; n=12). When expressed as per capsule or per ~1 teaspoon, concentration ranged from 0.1 to 145.2 mg (average 28 mg; n=12). Until US dietary supplement labeling comes under regulatory oversight similar to food guidelines, foods are a more dependable source for dietary phenolics than supplements.