Two genes involved in fat metabolism have been linked with vegetarian diets, suggesting that genetic variants may affect people’s ability to tolerate a diet without animal fats
By Clare Wilson
4 October 2023
People with certain gene variants may be more inclined towards vegetarian diets
Rafael Ben Ari/Getty Images
People’s likelihood of being vegetarian appears to be influenced by several genetic variants, and two of the three most important genes found so far seem to be involved in fat metabolism.
This hints that some people find it easier to give up meat because they naturally produce certain fat molecules, says Nabeel Yaseen at Northwestern University in Chicago. “Maybe there’s some fat that’s essential for some people to have in their diet but not for others,” he says.
About 5 per cent of people in the UK and US avoid all meat and fish. But surveys indicate that some people who say they are vegetarian still eat meat sometimes. That suggests that some people would like to be vegetarian but find it too hard, says Yaseen.
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Genetic factors are known to influence other aspects of diet, such as whether people like coffee or alcohol. To see if genes also affect vegetarianism, Yaseen and his team turned to the UK Biobank, a large study where people filled in lifestyle and medical surveys and had their DNA sequenced. They analysed about 5300 people who said they were strict vegetarians and another 330,000 people who were meat eaters.
Three gene variants were more common in vegetarians. Two, called NPC1 and RMC1, are involved in the transport and metabolism of cholesterol and other fatty molecules called glycolipids. The third gene, called RIOK3, has various functions, including affecting the immune system.
It isn’t known exactly how these genes could relate to vegetarianism. But one of the chief differences between animal-based foods and plant-based ones is the chemical make-up of their fats or oils, collectively known as lipids. Yaseen and his colleagues speculate that some people may function better on a vegetarian diet because they are more able to synthesise certain lipid molecules that are present in meat.