DHA Manuscript

Abstract

Purpose: To investigate the role of DHA supplementation in preventing Age Related Cognitive Decline (ARCD) in cognitive domains by conducting systematic review and meta-analysis.Methods: Relevant clinical trials were systematically searched at Medline-Pubmed, Scopus, Cochrane, ProQuest and Embase databases since inception to June 2018. The PRISMA guidelines were adhered for data abstraction, quality assessment and validity of included randomized control trails. Study details such as participant characteristics, DHA supplementation and cognitive function outcome measures i.e. memory, attention, working memory and executive function scores, were extracted and performed meta-analysis according to Cochrane guidelines. Additional meta-regression and subgroup analysis was performed to detect confounding variables and sensitivity of results respectively.Results: Ten studies including 2327 elderly individuals were part of the final results. Study exhibited minimal or no pooled incremental effects on memory (0.22, 95%CI=-0.17 to 0.61, I2=94.36%, p<0.001), attention (0.1, 95%CI=-0.04 to 0.25, I2=32.25%, p=0.18), working memory (0.01, 95%CI=-0.10 to 0.12, I2=0%, p=0.89) and executive function (0.03, 95%CI=-0.05 to 0.11, I2=78.48%, p<0.001) among DHA supplemented group. While results from standard mean difference between groups on memory (0.08, 95%CI=-0.12 to 0.28, I2=76.82%, p<0.001), attention (0.04, 95%CI=-0.09 to 0.23, I2=42.63%, p=0.11), working memory (-0.08, 95%CI=-0.26 to 0.10, I2=37.57%, p=0.17) and executive function (0.17, 95%CI=-0.01 to 0.36, I2=78.48%, p<0.001). Results remained unaffected in multiple sensitivity and sub-group analyses.Conclusions: Current evidences don’t support the role of DHA supplementation, in preventing / retarding ARCD of memory, executive function, attention and working memory.Protocol registered at PROSPERO (ID: PROSPERO 2018 CRD42018099401).