Marta Ribasés Haro
Head of the Psychiatric Genetics Unit
The journal PLoS One publishes the results of a study that investigates the genetic basis associated with strict vegetarianism and aims to identify possible related genetic variants. The researchers compared the genomes of 5,324 strict vegetarians and 329,455 controls using a genome-wide association study (GWAS). They identified a region of the genome associated with following a strict vegetarian diet that includes genes, such as NPC1 or RMC1, which are important in lipid metabolism and neuronal function. In addition, the authors identify other genomic regions suggestive of a potential role in dietary preferences.
Although these results suggest that genetic factors are involved in maintaining a long-term vegetarian diet, the study has important limitations. First, in order to identify genetic variants that predispose to initiating and maintaining a vegetarian diet through a GWAS study, it is necessary to analyse the DNA of many vegetarians and compare it with the DNA of a non-vegetarian control group. In this regard, the study includes a total of 5,324 strict vegetarians, which is too small a sample size to obtain conclusive results. For this reason, the results of the study should be considered preliminary until validated in larger samples to determine the role of genetics in dietary preference and maintenance of a vegetarian diet.
In addition, the authors identify significant differences between the vegetarian group and the control group in terms of Body-Mass Index and socioeconomic status. The vegetarian group consists mainly of women with lower Body-Mass Index and lower socio-economic status. However, the authors do not consider these potential confounding variables in the study, which may be undermining the study results.
Although the study supports previous evidence suggesting that there is a genetic basis to dietary choice, and that this may be related to differences in metabolism and taste perception, these results should be considered preliminary. If confirmed, the identification of genetic patterns associated with vegetarianism would help to better understand the underlying molecular mechanisms and allow the definition of individualised and effective dietary recommendations based on the genetic profiles of each individual.