Gene-vegetarianism interactions in calcium, testosterone, and eGFR identified in genome-wide analysis across 30 biomarkers

Existing vegetarian cohort studies have not considered the effects of genetic differences on health outcomes. First, we reduced inconsistencies among self-identified vegetarians in UK Biobank by utilizing two dietary surveys. Vegetarians were matched 1:4 with nonvegetarians for traditional association analyses, revealing significant effects of vegetarianism in 15/30 biomarkers. Cholesterol measures plus Vitamin D were significantly lower in vegetarians, while triglycerides were higher. A genome-wide association study revealed no genome-wide significant (GWS) associations with vegetarianism status. We performed genome-wide gene-vegetarianism interaction analyses for 30 biomarker traits (N=147,253). We detected a GWS interaction in calcium at rs72952628 ( P =4.47×10 −8 ). rs72952628 is in MMAA , a B 12 metabolism gene; B 12 has high deficiency potential in vegetarians. Gene-based interaction tests revealed two significant genes, RNF168 in testosterone ( P =1.45×10 −6 ) and DOCK4 in eGFR ( P =6.76×10 −7 ), which have previously been associated with testicular and renal traits, respectively. These findings indicate genotype can influence biomarker levels across vegetarians.