Dietary inflammatory index during pregnancy and its relationship with gyrification and IQ in young adult offspring

Maternal diet during pregnancy has been associated with brain development and cognitive function in offspring, but the mechanisms mediating these relationships remain poorly understood. We conducted a longitudinal neuroimaging follow-up of a prenatal birth cohort and used Food Frequency Questionnaires completed by the mother in mid-pregnancy to calculate prenatal Dietary Inflammatory Index (DII) and tested its relationship with brain gyrification, an index of early brain development, and IQ in young adults (n = 179, age 28–30). The longitudinal gyrification data were available for a subset of these individuals (n = 77, age 23–24). A higher maternal pro-inflammatory diet during pregnancy, as represented by higher DII, was associated with worse verbal IQ but not performance IQ in young adulthood. These findings were independent of sex and remained significant after adjusting for maternal education, maternal stressful life events during pregnancy, maternal smoking during pregnancy, prenatal supplements (e.g. folic acid, iron, zinc, calcium, vitamins), and maternal age at birth. Moreover, higher DII was associated with altered cortical gyrification in the early as well as the late 20, particularly in men. Gyrification of the anterior middle and inferior frontal gyrus mediated the relationship between prenatal DII and verbal IQ in young adulthood. These findings support the use of cortical gyrification as a proxy marker of early brain development and suggest it may underlie the relationship between maternal diet during pregnancy and its long-term impact on cognitive skills in offspring. They also have important implications for pregnant women who might be able to optimize the brain development and verbal IQ of their children through an anti-inflammatory diet.