Genetics of vegetarianism: A genome-wide association study

Abstract

A substantial body of evidence points to the heritability of dietary preferences. While vegetarianism has been practiced for millennia in various societies, its practitioners remain a small minority of people worldwide, and the role of genetics in choosing a vegetarian diet is not well understood. Dietary choices involve an interplay between the physiologic effects of dietary items, their metabolism, and taste perception, all of which are strongly influenced by genetics. In this study, we used a genome-wide association study (GWAS) to identify loci associated with strict vegetarianism in UK Biobank participants. Comparing 5,324 strict vegetarians to 329,455 controls, we identified one SNP on chromosome 18 that is associated with vegetarianism at the genome-wide significant level (rs72884519, β = -0.11, P = 4.997 x 10−8), and an additional 201 suggestively significant variants. Four genes are associated with rs72884519: TMEM241, RIOK3, NPC1, and RMC1. Using the Functional Mapping and Annotation (FUMA) platform and the Multi-marker Analysis of GenoMic Annotation (MAGMA) tool, we identified 34 genes with a possible role in vegetarianism, 3 of which are GWAS-significant based on gene-level analysis: RIOK3, RMC1, and NPC1. Several of the genes associated with vegetarianism, including TMEM241, NPC1, and RMC1, have important functions in lipid metabolism and brain function, raising the possibility that differences in lipid metabolism and their effects on the brain may underlie the ability to subsist on a vegetarian diet. These results support a role for genetics in choosing a vegetarian diet and open the door to future studies aimed at further elucidating the physiologic pathways involved in vegetarianism.

Gene-vegetarianism interactions in calcium, estimated glomerular filtration rate, and testosterone identified in genome-wide analysis across 30 biomarkers

“…Our null finding is similar to a recent GWAS in a Japanese cohort [ 26 ]. We nominally replicated the single GWS variant found in a recent GWAS in UKB Europeans by Yaseen et al (rs72884519) [ 25 ], and found a similar effect size (β = -0.09; P = 0.002). We attribute the discrepancy in P -values between our study and theirs ( P = 4.997×10 −8 ) to important differences in our respective vegetarianism definitions.…”

“…There is no data field on the IA to self-identify directly as vegetarian, and we have described above how single time-point survey data can be unreliable [ 14 – 16 ]. Yaseen et al [ 25 ] therefore included 2,566 vegetarians (~48% of their cases) that we did not classify as such. Furthermore, we cannot determine what is meant when their methods refer to “the diet by 24-hour recall questionnaire, which captured ~110K of the respondents,” [ 25 ] because the 24HR has spanned approximately 211,000 respondents since its release in September 2012 [ 51 ].…”

“…Specific genetic variants have been significantly associated with quantitative measures of plant-eating [ 23 , 24 ]. A recent GWAS in UK Biobank Europeans, which used a single survey instance to classify vegetarians, found one variant at genome-wide significance impacting vegetarianism status (rs72884519; P = 4.997×10 −8 ) [ 25 ], while a GWAS in a Japanese cohort found none [ 26 ]. To discover how the health impacts of vegetarianism can depend on the genetic background of an individual, we considered gene-environment interactions (G×E), which can produce synergistic (non-additive) effects on health outcomes that genetic or environmental factors alone would not [ 27 ].…”