Decisions about our type of diet can be guided by the recommendations of experts, although we are frequently influenced by fashion, the environment in which we live and, of course, our economic capacity to fill the shopping basket with more or less food. expensive. However, it may not have occurred to us that our genes have something to do with it. And it seems so, as new research reveals that a person’s genetic makeup plays a key role in their chances of following a strict vegetarian diet.
This is the first peer-reviewed study to examine the relationship between genetics and strict vegetarianism and was conducted by researchers at Northwestern University Feinberg School of Medicine in collaboration with scientists at Washington University in St. Louis and Edinburgh. , United Kingdom. The findings have been published in PLOS ONE and lay the foundation for future research that could have implications for dietary recommendations and the production of meat substitutes.
Dr. Nabeel Yaseen, professor emeritus of pathology at Northwestern University Feinberg School of Medicine, wondered whether all humans would be able to subsist long-term on a strict vegetarian diet, since a large majority of those who consider themselves Vegetarians (about 48 to 64%) admit that they eat fish, poultry or red meat.
“While religious and moral considerations play an important role in the motivation to adopt a vegetarian diet, our data suggest that the ability to follow such a diet is limited by genetics.”
According to Yaseen, this suggests that environmental or biological limitations override the desire to follow a vegetarian diet. “It seems like there are more people who would like to be vegetarians than actually are, and we think it’s because there’s something ingrained here that people may be missing.”
Genes involved in lipid metabolism and brain function
The researchers’ goal was to test whether genetics influence a person’s ability to follow a vegetarian diet. To do this, they compared genetic data from the UK Biobank of 5,324 strict vegetarians (who did not consume fish, poultry, or red meat) with 329,455 controls. All study participants were white Caucasians to make the sample homogeneous and avoid confusion due to ethnic origin.
The researchers identified three genes that are significantly associated with vegetarianism and another 31 genes that are potentially associated. They further found that several of these genes, including two of the top three (NPC1 and RMC1), are involved in lipid (fat) metabolism or brain function.
“One area where plant products differ from meat is complex lipids,” Yaseen said. “My hypothesis is that there may be lipid components present in meat that some people need. And perhaps people whose genetics favor vegetarianism are able to synthesize these components endogenously. However, at this point, this is mere speculation and much more work needs to be done to understand the physiology of vegetarianism.”
Vegetarians are still a minority
These scientists explain in their article that the main motivations for adopting a vegetarian diet are religious and moral, although there are studies that have shown the health benefits of following a vegetarian diet. It is true that vegetarians are still a minority, but there are more and more of them, and in Spain in 2021 the number of veggie people grew by 34%, which are already 13% of the population (1.4% vegetarian, 0 ‘8% vegan and 10.8% flexitarian), according to data from the Spanish Vegetarian Union.
In Yaseen’s opinion, the determining factor why most people prefer to eat meat products is not only the taste, but also how their body metabolizes food. “While religious and moral considerations certainly play an important role in the motivation to adopt a vegetarian diet, our data suggest that the ability to follow such a diet is limited by genetics,” says Yaseen. “We hope that future studies will lead to a better understanding of the physiological differences between vegetarians and non-vegetarians, which will allow us to offer personalized dietary recommendations and produce better meat substitutes,” he concludes.
José M. Ordovás, Director of Nutrition and Genomics at Tufts University in Boston (USA), member of IMDEA-Alimentación (Madrid) and CIBEROBN (Carlos III Health Institute), believes in statements to SMC Spain that “together, This and previous studies provide evidence pointing to the heritability of dietary preferences, in this specific case, vegetarianism. The uniqueness of the work appears to lie in its deep focus on the genetic factors underlying vegetarianism using a large data set from the UK Biobank.”
The expert highlights, however, that it has quite a few limitations, such as “it is based on self-reported dietary data,” which may not be accurate. The study population is not diverse, which “may affect the generalizability of the results, which may not extend to other ethnic or cultural groups.” And the reasons why people adopted vegetarianism are also unknown, “which may be multiple and with biological, psychological, cultural, environmental, religious, etc. roots. “This information would have been essential to differentiate genes that are more related to lipid metabolism or those that are expressed in the brain.”
Also in statements collected by SMC Spain, Marta Ribasés Haro, Coordinator of the Vall d’Hebron Research Institute Psychiatric Genetics Unit, points out: “although the study supports previous evidence that suggests that there is a genetic basis in the choice of diet, and that this may be related to differences in metabolism and flavor 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 would allow defining individualized and effective dietary recommendations based on the genetic profiles of each individual.”
