Marketplace Analysis Demonstrates Quality Control Standards Needed for Black Raspberry Dietary Supplements

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 (18.1–2,904.8 mg/100 g; 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.