Maternal and childhood plant-based diets with brain morphology and cognitive performance in adolescence

Plant-based diets (PBDs) are increasingly discussed in the context of sustainable and healthy eating. However, evidence on PBDs during early pregnancy and childhood in relation to brain morphology and cognitive performance remains largely unknown. We aimed to investigate whether maternal and childhood overall, healthful, and unhealthful PBDs are associated with offspring brain morphology and adolescent cognitive performance.

We included mother-child dyads with dietary intake measured during early pregnancy (n = 2952) and childhood at age eight years (n = 2922) and with at least one brain magnetic resonance imaging assessment at age 10 or 14 years from the prospective population-based Generation R Study. Dietary intake during early pregnancy and childhood was assessed with food-frequency questionnaires. We constructed three plant-based diet indices (PDIs): an overall PDI, a healthful PDI (hPDI), and an unhealthful PDI (uPDI). Cognitive performance was assessed at 14 years using 4 subtests of the Wechsler Intelligence Scale for Children-Fifth Edition. Associations were examined using multivariable linear mixed models and linear regression models.

After adjustment for socioeconomic and lifestyle factors, higher maternal hPDI scores were associated with higher full-scale IQ (per SD, B = 0.54, 95% CI: 0.09, 1.00) but not with brain volumes, whereas higher childhood hPDI scores were associated with larger total brain (per SD, B = 7.97, 95% CI: 4.43, 11.51), white matter, gray matter, subcortical volumes, and better verbal comprehension. In contrast, higher maternal uPDI scores were associated with smaller total brain volume (per SD, B = -4.03, 95% CI: -8.02, -0.04), cerebral gray matter and subcortical volumes and lower IQ (per SD, B = -0.84, 95% CI: -1.35, -0.32), and childhood uPDI scores were inversely associated with matrix reasoning but not with brain volumes. Childhood PDI scores, particularly hPDI scores, showed widespread positive associations with cortical morphology, whereas maternal PDI scores showed no significant associations.

Our findings suggest that plant-based diet quality during early pregnancy and childhood shows distinct associations with brain morphology and cognitive performance up to adolescence, although the clinical and developmental relevance of the observed differences should be further investigated.