Maternal and paternal dietary quality, dietary inflammation status, and offspring DNA methylation

Abstract

Objectives: Maternal diet and chronic inflammation may influence early-life offspring health. Recent observations indicate that early nutritional exposures may contribute to epigenetic modifications in the progeny. However, few studies have evaluated the effect of parental dietary quality on offspring DNA methylation. We aim to fill this gap by elucidating the influence of whole-diet maternal and paternal dietary quality and inflammatory potential on DNA methylation in their children at nine years in the Lifeways Cross-generation cohort. Method(s): Families were recruited around 16 weeks of gestation in the Republic of Ireland between 2001 and 2003. Maternal dietary intake during the first trimester and paternal diet of the 12 previous months were assessed with a food-frequency questionnaire. We used the healthy eating index (HEI-2015), a measure of overall diet quality, by scoring adherence to dietary guidelines and the energy-adjusted dietary inflammation index (E-DII). DNA methylation in saliva samples of 264 children was assessed using the Illumina Infinium HumanMethylationEPIC (EPIC array). Using an agnostic epigenome-wide approach we examined associations of each dietary score with methylation beta-values of each CpG site, including child sex, batch effect, smoking, cellular composition as covariates. Result(s): After adjusting for covariates and multiple tests, maternal HEI-2015 scores were inversely associated with DNA methylation at 1 CpG site (cg21840035, p-value=5.5x10-8) located near the PLEKHM1 gene, whose functions involve regulation of bone development. An increase in paternal HEI score was related to lower methylation at one CpG site (cg22431767, p-value=4.1x 10-8) located near cell signaling gene LUZP1. No significant associations between maternal or paternal E-DII and DNA methylation at individual CpG sites were observed. Conclusion(s): We report, for the first time, that parental dietary quality, determined by the HEI-2015 score, in the prenatal period was associated with long-term epigenetic changes in their children. Our results encourage further research in larger populations with different dietary intake and investigation of the functional implications of the genes involved to understand how they may affect offspring health.