Effect of n-3 long-chain polyunsaturated fatty acids on mild cognitive impairment: a meta-analysis of randomized clinical trials

N-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) have positive effect on cognitive function with mild cognitive impairment (MCI) is still controversial. The aim for this meta-analysis was to assess the scientific evidence published in the last 10 years on the effects of n-3 LC-PUFAs intake on MCI patients to explore whether n-3 LC-PUFAs have positive effective. A comprehensive literature search was developed using the Google Scholar, EMBASE, and PubMed database. The pooled effect for all studies was calculated using random-effects model. And the terms of weighted mean difference (WMD) with 95% confidence interval (CI) was pooled and indicated the effects. Heterogeneity was assessed by I2 statistics. A total of seven randomized clinical trials involving 213 cases of intervention and 221 cases of placebo were included in this analysis. Compared with placebo, n-3 LC-PUFAs supplements effectively improved cognition in elders with MCI (WMD = 0.85, 95% CI: 0.04–1.67, Z = 2.05, P = 0.04). Slight heterogeneity was detected across studies. Our results provided further evidence that n-3 LC-PUFAs may have beneficial effect in elderly with MCI.