N-3 long-chain polyunsaturated fatty acid supplements boost cognition in elderly

Elderly adults with mild cognitive impairment (MCI) may derive benefits from N-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs), reports a recent meta-analysis.

Researchers performed a comprehensive literature search of the Google Scholar, Embase and PubMed databases. They retrieved seven randomized controlled trials, corresponding to 213 patients on active intervention and 221 on placebo. Studies that combined fatty acids with other interventions, and those that were of other methodological designs, were ineligible.

Across the included studies, the duration of the intervention ranged from 3–24 months. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) doses ranged from 180–1,300 and 40–720 mg, respectively. Outcome was cognitive function, as measured by the mini-mental state examination (MMSE).

Pooled analysis found that n-3 LC-PUFAs had a significant and positive correlation with MMSE cognitive function (weighted mean difference [WMD], 0.85, 95 percent confidence interval, 0.04–1.67; p=0.04). There was slight heterogeneity of evidence, which was of borderline significance (p=0.05).

Sensitivity analysis, carried out by removing studies one at a time, revealed that none had a particularly strong influence on the principal findings, with the WMD estimates changing only minimally.

All included studies scored at least an 8 on the methodological quality score, suggesting good quality overall.

“[T]his meta-analysis demonstrates that n-3 LC-PUFAs may have beneficial effect in the older [population] with MCI. And large-scale randomized clinical trials are needed to further confirm our findings,” researchers said.