Effect of omega-3 fatty acids on sleep: a systematic review and meta-analysis of randomized controlled trials

Omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs) have been reported to improve sleep quality in several studies, but meta-analyses have been inconclusive. We conducted this study to investigate the effects of omega-3 LC-PUFAs on sleep in clinical trials. The study was planned in accordance with the criteria of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-2020), and was performed by searching PubMed, The Cochrane Library, and Ichushi-web databases. Randomized controlled trials and clinical trials with control groups were included. Finally, eight studies were selected for inclusion in this study. Sleep efficiency was significantly higher in the omega-3 LC-PUFA group than in the control group, while sleep latency and total sleep duration did not differ significantly. Subjectively assessed sleep was significantly improved by omega-3 LC-PUFA, but heterogeneity was so high that a subgroup analysis based on dose of omega-3 supplementation was performed. It showed low heterogeneity and significant improvement in the omega-3 LC-PUFA group compared with the control group. Omega-3 LC-PUFAs have been shown to may improve sleep quality. Further studies are needed to confirm the relationship between omega-3 LC-PUFAs and sleep. The protocol for this review was registered in UMIN000052527.