Differences in DNA Methylation Patterns Between Vegans and Non-vegetarians in the AHS-2 Cohort (FS11-06-19)

Objectives It is unclear how diets differing in content of animal products affect DNA methylation patterns. We sought to determine if DNA methylation patterns differed between vegans and non-vegetarians in the Adventist Health Study-2 (AHS-2) cohort. Methods DNA methylation was profiled using the Infinium Human Methylation 450 K BeadChip in white blood cells of 137 participants in the AHS-2 cohort classified as vegan (57) or non-vegetarian (80) based on validated diet history data. Linear regression models were generated to test associations between diet pattern and methylation, where the response variable represented methylation intensity for individual CpG sites. This was repeated for sites separated into gene regions or in relation to CpG islands. CpG methylation was also averaged across each gene. The permutation-identified null distribution, false discovery rate of Storey et al was used to adjust for multiple testing. Results A total of 53,809 individual CpG sites were estimated to be differentially methylated (non-null). Of these, with this small sample, we could individually identify only up to 5.5% (differing by gene region) at FDR