Omega-3 fatty acids and cognitive function

Purpose of reviewThe aim is to provide an update on omega-3 polyunsaturated fatty acids (n-3 PUFA) in preventing cognitive decline and dementia.Recent findingsProspective studies and three new meta-analyses suggest that fish or n-3 PUFA intake are associated with a reduction in development of mild cognitive decline and Alzheimer's disease. Supplementation with docosahexaenoic acid (DHA) in randomized controlled trials (RCTs) in those with mild cognitive impairment showed benefit on cognitive decline, whereas there was no benefit in Alzheimer's disease. In cognitively healthy individuals with clinical coronary artery disease (CAD), 3.36 g EPA and DHA daily slowed cognitive ageing by 2.5 years. Of 15 RCTs in cognitively healthy individuals age more than 55 years, seven reported benefit, whereas eight did not. Potential mechanisms for differences in outcomes include dose, trial duration, apolipoproteinE genotype, sex, stage and rate of cognitive decline, cognitive testing employed and individual characteristics. The downstream product of DHA, neuroprotectin D1, may be involved in beneficial effects.Patients with early memory complaints or a family history of dementia and those with CAD should be counselled on the potential benefits of fish intake and supplementation with n-3 PUFA. ApolipoproteinE4 carriers may especially benefit from DHA supplementation prior to development of cognitive decline.

Automated summary

The article provides an update on the research progress regarding the use of omega-3 polyunsaturated fatty acids (n-3 PUFA) for preventing cognitive decline and dementia. Recent studies suggest that fish or n-3 PUFA intake may be associated with a reduced risk of mild cognitive decline and Alzheimer's disease. The results from randomized controlled trials indicate that supplementation with docosahexaenoic acid (DHA) may benefit individuals with mild cognitive impairment, but not those with Alzheimer's disease.