Vegetarianism: New study shows some people might be 'hard-wired' to thrive on meat-free diets

It might be genetically easier for some people to give up meat than others, a new study has found.

Research on UK adults led by scientists from Northwestern University in the US has identified 34 genes that are potentially linked to vegetarianism, which could mean some people are “hard-wired” to be able to live on a vegetarian diet more easily.

In the study, published this week in peer-reviewed journal PLOS One, researchers said that people chose a vegetarian diet for a range of reasons - including religion, ethics, environmentalism and health - but personal taste, metabolism and the effects different foods had on their bodies came into it too.

However, there had been little work examining the role genetics could play in these dietary choices, they wrote.

The team compared the genes of 5,324 strict vegetarians to 329,455 non-vegetarians, all of whom were taking part in the UK Biobank study. After examining more than 330,000 genomes, they identified three genes which appeared to have a significant link to a vegetarian diet, while 31 others were deemed to be “potentially” associated.

The authors wrote that several of these genes had “important functions in lipid (fat) metabolism and brain function". Their data also suggested “that adherence to a strict vegetarian diet is influenced by genetics".

Co-author Dr Nabeel Yaseen, a pathology professor emeritus at Northwestern, told PA whether all humans were capable of subsisting long-term on a strict vegetarian diet had not been seriously studied.

“It seems there are more people who would like to be vegetarian than actually are, and we think it’s because there is something hard-wired here that people may be missing," he said.

One area in which plant products differ from meat was complex fats, Dr Yaseen continued. “My speculation is there may be lipid components present in meat that some people need... Maybe people whose genetics favour vegetarianism are able to synthesise these components endogenously" - or create these in their own bodies.

“However, at this time, this is mere speculation and much more work needs to be done to understand the physiology of vegetarianism," he added.

The Vegetarian Society told PA that previous figures had shown that the proportion of vegetarians “almost doubled” between 2012 and 2019.

“That would seem to suggest something other than underlying genetic factors are at play; people go vegetarian because, more and more, they are concerned about climate, about animal welfare or about their health, and it represents a solution.”

Another recent study by the University of Oxford has found meat-free diets are linked to huge environmental benefits - vegan diets even more so. The study, on tens of thousands of Brits, found completely plant-based diets produce just a quarter of the greenhouse gases of high-meat diets.

It also found meat-free eating had a substantially lower environmental impact, across metrics including land use, water pollution risk, water use and biodiversity loss.