Omega-3 fatty acid supplementation and cognitive function: are smaller dosages more beneficial?

Abstract

As longevity increases, so does the global prevalence of cognitive dysfunction. Numerous lifestyle and/or dietary interventions such as omega-3 fatty acids have been suggested to improve memory. Therefore, this study examined the consistency and strength of the impact of supplementation of omega-3 fatty acids on overall cognitive function using systematic reviews and meta-analytic methods. Of 905 studies retrieved from all searches, 12 randomized controlled trials were included in the meta-analysis. There were differences between studies reporting outcomes for single memory function parameters. Subgroup analysis of doses used (low versus high) indicated that subjects receiving low (<1.73 g/day) doses of omega-3 fatty acids had a significant reduction in cognitive decline rate (−0.07, 95% confidence interval −0.01, −0.02) but there was no evidence for beneficial effects at higher doses (+0.04, 95% confidence interval −0.06, +0.14) compared with the placebo group. This study suggests that omega-3 fatty acids may be beneficial in preventing memory decline at lower doses.

Keywords:

• cognitive impairment
• Alzheimer’s disease
• dietary fatty acids
• omega-3
• docosahexaenoic acid

Acknowledgments

The authors are grateful to Miss Mahdieh Naderali, University of Leicester, for her editorial assistance in preparing this manuscript.

Disclosure

The authors report no conflicts of interest in this work.