Scope: There is extensive pre-clinical evidence for utility of curcuminoids across many diseases with a particular focus on cancer prevention, yet there remains a paucity of clinical evidence for its approved use. To assess current knowledge on the broader potential for clinical efficacy of curcumin and in particular, in cancer prevention strategies, this study undertook a systematic review determining the number and quality of randomized controlled trials (RCTs) undertaken across any pathology.
Methods and results: Search strategies for RCTs using a quantifiable amount of curcuminoids, are applied across Medline (Medical Literature Analysis and Retrieval System Online), Embase (Excerpta Medica dataBASE), Cochrane and clinicaltrials.gov. There are 314 curcuminoid-based RCTs, with 100 of these revealing significant within- and between-group changes relating to the primary outcome. Twenty three studies are conducted in a setting where there is an increased risk of cancer. Fifteen of these meet all prescribed quality criteria, and 10 reveal positive outcomes.
Conclusions: A substantial number of studies reveal positive outcomes following curcumin use. However, despite the vast array of preclinical data, there are relatively few RCTs conducted in the prevention setting. Future approaches to trials must deliver improved robustness and credibility of curcumin-related research to facilitate approvals for use in clinical settings.
Keywords: cancer prevention; curcuminoids; quality risk of bias; randomized control trials; systematic review.
© 2021 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH GmbH.