OC19.07: *Effect of Mediterranean diet intervention during pregnancy on maternal brain: a secondary analysis of the IMPACT BCN randomised clinical trial

Mediterranean diet (MD) has positive effects on mid-older adult brain, however there is scarce information in pregnant individuals. We aimed to evaluate the effect of a structured MD intervention during pregnancy on the cortical structure of the maternal brain. This study was a secondary analysis of the IMPACT BCN, a randomised clinical trial with 1221 pregnant women randomly allocated into three groups at 19-23 weeks of gestation: MD intervention, Mindfulness-Based Stress Reduction program, or usual care. Maternal brain magnetic resonance (MR) was performed at third trimester of pregnancy in a proportion of participants randomly selected from the three study groups. For this study, data from MD and usual group were analysed. Maternal dietary intake, adherence to the MD and biomarkers of metabolites were evaluated with Food Frequency Questionnaire, 17-item MD adherence and plasma/urine samples, respectively. Cluster-wise analysis was used to assess cortical brain morphometric differences between intervention groups. Linear regression analysis was used to assess the association in region of interest of maternal brain areas and dietary variables. MD women (n = 34) had significantly larger surface areas in the right precuneus (90%CI: <0.0001–0.0004, p < 0.001) and left superior parietal (90%CI: 0.026–0.033, p = 0.03), compared to the usual care group participants (n = 37). Right precuneus area was larger in the participants with high adherence to MD (Adjusted mean difference, D, 177.2mm2, 95%CI 12.0-342.4), high intake of walnuts (D 210.8mm2, 95% CI 13.2-408.4), and high concentrations of urinary hydroxytyrosol (HXT) (b 74.3mm2, 95% CI 21.3-127.4). Left superior parietal area was associated with high intake of walnuts (D 375.7mm2, 95% CI 78.9-627.4), and high concentrations of urinary HXT (b 119.3mm2, 95% CI 39.0-199.6). Promotion of MD during pregnancy has a significant effect on maternal brain structure.