Savor the flavor - a randomized double-blind study on taste-enhanced placebo analgesia in healthy volunteers

Abstract We conducted a randomized, double-blind, between-group study to investigate how the taste of oral medication affects placebo analgesia. Over three sub-studies, 318 healthy volunteers (297 included) were subjected to experimental tonic cold water pain (cold pressor test) before and after receiving taste-neutral (water), bitter (quinine), sweet (saccharine), or no placebo drops. Pain ratings indicated that taste enhances placebo analgesia. This effect was small but accounted for a substantial portion of the overall placebo effect and was comparable to WHO stage 1 analgesic effects. Moreover, placebo treatments were associated with an increase in peak heart rate response to cold water. Adverse effects were minimal. These results indicate that added taste may be an easy-to-implement, cost-effective, and safe way to optimize treatment outcomes and that taste-neutral preparations may reduce placebo-related outcome variance in clinical trials. Further studies are needed to test if these findings can be translated into clinical scenarios.