The Impact of Omega-3 on Improving Sleep Quality: A Systematic Review of Current Clinical Research

Abstract

Introduction: Omega-3 fatty acids are known to improve cardiovascular and metabolic outcomes. While studies have suggested that omega-3 may also enhance sleep quality and regulate melatonin, the data on its efficacy for individuals with poor sleep quality or related disorders must be more consistent. We aim to pave the way for future investigations, ultimately contributing to the clinical management of sleep health. Methods: 87 articles were retrieved from MEDLINE and Cochrane databases through a systematic search strategy, and 19 articles from 2002 to 2022 were included. Inclusion criteria encompassed randomized controlled trials (RCTs) and observational studies focused on the impact omega-3 on outcomes related to sleep clinical parameters. Exclusion criteria included preclinical studies and literature reviews. Results: The review identified 19 eligible studies, consisting of 9 RCTs and ten observational studies. The results displayed a complex relationship between omega-3 supplementation and sleep quality, with some studies suggesting positive effects, particularly in specific subpopulations. In contrast, others showed no significant impact or even negative effects on sleep. Among the RCTs, 7 showed positive and promising results in favor of omega-3 supplementation for sleep quality, while 1 RCT indicated the need for further studies, and 1 RCT suggested no benefit of omega-3 on sleep quality. Among observational studies, 7 reported positive and promising outcomes with omega-3 supplementation, 2 indicated no benefit in improving sleep quality, and 1 suggested further studies. Conclusion: Based on the available data, our systematic review found that omega-3 improved sleep quality in 74% of the included clinical research; however, such evidence still needs to be conclusive due to high heterogeneity among study designs. Therefore, well-designed clinical studies are required to confirm this conclusion.