The Vegetarian Code: Your Genes Might Dictate Your Diet

Summary: A new study illuminates a potential genetic foundation underpinning an individual’s adherence to a strict vegetarian diet.

Analyzing genetic data from over 5,000 strict vegetarians and 329,455 controls, researchers identified genes significantly associated with vegetarianism, primarily influencing lipid metabolism and brain function.

The groundbreaking study, positioning genetics as a plausible factor influencing dietary preferences beyond moral and religious considerations, paves the way for nuanced understandings of diet and genetics.

The insights gleaned beckon further research to elucidate the physiological divergences between vegetarians and non-vegetarians, potentially informing tailored dietary recommendations and the development of enhanced meat substitutes.

Key Facts:

  1. Genetic Predisposition: The study unveils a potential genetic predisposition influencing adherence to a vegetarian diet, identifying three genes significantly and 31 genes potentially associated with vegetarianism, many impacting lipid metabolism and brain function.
  2. Vegetarian Divergence: Despite growing popularity and established health benefits of a vegetarian diet, a large proportion of self-identified vegetarians often consume some form of meat, suggesting potential biological or environmental factors impinging on strict adherence to the diet.
  3. Future Implications: While the study offers a pioneering glimpse into the genetics of dietary habits, further research is imperative to comprehend the physiological nuances between vegetarians and non-vegetarians, which could shape future dietary guidelines and enhance meat substitute production.

Source: Northwestern University

From Impossible Burger to “Meatless Mondays,” going meat-free is certainly in vogue. But a person’s genetic makeup plays a role in determining whether they can stick to a strict vegetarian diet, a new Northwestern Medicine study has found.  

The findings open the door to further studies that could have important implications regarding dietary recommendations and the production of meat substitutes.

“Are all humans capable of subsisting long term on a strict vegetarian diet? This is a question that has not been seriously studied,”said corresponding study author Dr. Nabeel Yaseen, professor emeritus of pathology at Northwestern University Feinberg School of Medicine. 

A large proportion (about 48 to 64%) of self-identified “vegetarians” report eating fish, poultry and/or red meat, which Yaseen said suggests environmental or biological constraints override the desire to adhere to a vegetarian diet.

“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.” 

Several genes involved in lipid metabolism, brain function

To determine whether genetics contribute to one’s ability to adhere to a vegetarian diet, the scientists compared UK Biobank genetic data from 5,324 strict vegetarians (consuming no fish, poultry or red meat) to 329,455 controls. All study participants were white Caucasian to attain a homogeneous sample and avoid confounding by ethnicity.

The study identified three genes that are significantly associated with vegetarianism and another 31 genes that are potentially associated. Several of these genes, including two of the top three (NPC1 and RMC1), are involved in lipid (fat) metabolism and/or brain function, the study found. 

“One area in which plant products differ from meat is complex lipids,” Yaseen said. “My speculation is there may be lipid component(s) present in meat that some people need. And maybe people whose genetics favor vegetarianism are able to synthesize these components endogenously.  However, at this time, this is mere speculation and much more work needs to be done to understand the physiology of vegetarianism.”

The study will be published Oct. 4 in the journal PLOS ONE*. It is the first fully peer-reviewed and indexed study to look at the association between genetics and strict vegetarianism.

Why do most people eat meat?

Religious and moral considerations have been major motivations behind adopting a vegetarian diet, and recent research has provided evidence for its health benefits. And although vegetarianism is increasing in popularity, vegetarians remain a small minority of people worldwide. For example, in the U.S., vegetarians comprise approximately 3 to 4% of the population. In the U.K., 2.3% of adults and 1.9% of children are vegetarian. 

This raises the question of why most people still prefer to eat meat products. The driving factor for food and drink preference is not just taste, but also how an individual’s body metabolizes it, Yaseen said. For example, when trying alcohol or coffee for the first time, most people would not find them pleasurable, but over time, one develops a taste because of how alcohol or caffeine makes them feel. 

“I think with meat, there’s something similar,” Yaseen said. “Perhaps you have a certain component — I’m speculating a lipid component — that makes you need it and crave it.”

If genetics influence whether someone chooses to be a vegetarian, what does that mean for those who don’t eat meat for religious or moral reasons? 

“While religious and moral considerations certainly play a major role in the motivation to adopt a vegetarian diet, our data suggest that the ability to adhere to such a diet is constrained by genetics,” Yaseen said.

“We hope that future studies will lead to a better understanding of the physiologic differences between vegetarians and non-vegetarians, thus enabling us to provide personalized dietary recommendations and to produce better meat substitutes.”

The study, titled “Genetics of Vegetarianism: A Genome-Wide Association Study,” was conducted in collaboration with scientists from Washington University in St. Louis and Edinburgh, United Kingdom.

About this diet and genetics research news

Author: Kristin Samuelson
Source: Northwestern University
Contact: Kristin Samuelson – Northwestern University
Image: The image is credited to Neuroscience News

Original Research: Open access.
Genetics of Vegetarianism: A Genome-Wide Association Study” by Nabeel Yaseen et al. PLOS ONE


Genetics of Vegetarianism: A Genome-Wide Association Study

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: TMEM241RIOK3NPC1, 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: RIOK3RMC1, and NPC1.

Several of the genes associated with vegetarianism, including TMEM241NPC1, 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.

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  1. I discovered 10 years ago I am celiac (gluten intolerant) so I eat mostly vegetables and fresh fruits, nothing frozen because when it’s frozen the enzymes are killed and I need enzymes to digest food and frozen foods are usually overly processed, then the minerals and vitamins are leeched out. I also have an extra X chromosone(is that a gene problem)?
    I also have temporal lobe epilepsy so I’m careful… believe that vitamins and minerals are important. I munch on fresh parsley because they have essential fatty acids and they lessen water retention….so when I remove my socks there’s not a ring around my leg. I eat my raw avocado dinner 3 & 1/2 hours before bedime, it’s tasty and fills me up until 10:00 p.m.

  2. At a very basic level our mouth tells us of our evolutionary history. Meat provides us with nutritional components that plants can’t commonly do so. I have a feeling that there’s a hint of eugenics in this study.

  3. If the vegetarians weren’t studied before they became vegetarians, there is no way of knowing if the diet changed the genetics or if the genetics were there to begin with. Many things change our genes.

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