Effects of Different Proportions of DHA and ARA on Cognitive Development in Infants: A Meta-Analysis

Objectives: Previous studies have assessed the effect of docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (ARA, 20:4n-6)-supplemented infant formula on brain development and cognitive function in infants. However, the results have been inconsistent. The aim of this systematic review and meta-analysis was to assess the effect of DHA and ARA supplementation on cognitive function in infants from randomized controlled trials (RCTs). Methods: We systematically searched and identified relevant literature from the PubMed, Web of Science, and Embase databases up to July 2024. Standard methods were applied to assess publication bias, sensitivity analysis, and heterogeneity among the included studies. A total of nine RCTs were included in the study, which comprised 1039 subjects. Results: Meta-analysis showed significantly positive effects of DHA and ARA supplementation on cognitive development in infants (Standardized Mean Difference (SMD): 0.21; 95% CI: 0.03, 0.38). No significant difference was found in Mental Development Index (MDI) score (Weighted Mean Difference (WMD): 0.20; 95% CI: −0.03, 0.43) and Psychomotor Development Index (PDI) score (WMD: 0.12; 95% CI: −0.11, 0.35) in Bayley Scales of Infant and Toddler Development compared with the control group. In subgroup analysis, when DHA/ARA was 0.5–1, PDI had a significant difference (WMD: 0.48; 95% CI: 0.03, 0.93) compared with the control group, with no significant difference between heterogeneity (I2 = 46.4%, p = 0.155). In comparison to the control group, significant differences were observed in MDI when DHA/ARA levels were between 0.5 and 1 (WMD: 0.55; 95% CI: 0.07, 1.02), with no significant difference between heterogeneity (I2 = 51.6%, p = 0.127). Conclusion: When the DHA /ARA was 0.5–1 can significantly improve the cognitive function in infants.