Effects of Maternal Peanut Intake and Breastfeeding Duration on Offspring DNA Methylation

Emerging evidence suggests that maternal diet during pregnancy and breastfeeding may influence epigenetic modifications in offspring genes related to neurodevelopment and inflammation, although the specific mechanisms and long-term implications of these effects are not well understood. This study evaluated the influence of maternal peanut intake during pregnancy and/or breastfeeding on the relationships between breastfeeding duration, household income, and child race with DNA methylation of genes associated with inflammation and neurodevelopment. Children aged 2-7 years (N = 35) provided saliva samples and their parent/guardian completed questionnaires related to maternal diet during pregnancy and breastfeeding as well as family demographics. We found that maternal consumption of peanuts and peanut butter during pregnancy may enhance the epigenetic sensitivity of the BDNF gene region to breastfeeding duration. Among participants with maternal consumption of both peanuts and peanut butter during pregnancy, longer breastfeeding duration was associated with increased DNAm of BDNF at 12 CpG sites and decreased DNAm at 3 CpG sites. Interestingly, for participants with maternal consumption of peanut butter only, longer breastfeeding duration was associated with decreased BDNF DNAm, suggesting a potential for increased gene expression. A similar pattern emerged when household income was considered. Among mothers who consumed both peanuts and peanut butter during breastfeeding, BDNF DNAm increased with increasing household income. In contrast, no interaction emerged between income and BDNF DNAm when mothers consumed peanut butter only during breastfeeding. Additionally, patterns by race/ethnicity differed depending on maternal diet. Among BIPOC participants, IL6-AS1 DNAm was lower compared to white participants when mothers consumed both peanuts and peanut butter during pregnancy. However, when mothers consumed only peanut butter, BIPOC participants showed higher IL6-AS1 DNAm levels compared to their white peers.