Plant-based diets—whether that be strict veganism, vegetarianism, or flexitarianism—have been common for so long that it’s safe to say they’re no longer a fad. In fact, various surveys show that between 4 to 6 percent of U.S. adults are vegetarian or vegan. But sticking with that eating pattern can be challenging for many people. A 2014 survey from Faunalytics (formerly the Humane Research Council) found that 84 percent of vegetarians and vegans abandon their diet, with a third of those ditching the diet after three months of less.

People might assume that dietary choices come down to willpower. But that’s not necessarily the case, particularly when it comes to eating vegetarian and vegan. A study published last fall in the journal PLOS One¹ found that it might actually be our genes that strongly influence our ability to strictly adhere to a vegetarian lifestyle.

How your genes can influence vegetarian and vegan eating

Published in October of 2023, the study conducted by Northwestern University’s Medicine program is the first to examine the role of genetics in someone’s ability to be a strict vegetarian. This objective came about as researchers pondered how many vegetarians in their lives still ate meat, poultry, and fish. Given that there are other genetically-determined things that can play into dietary choices² (including a person’s metabolism and taste preferences), the researchers wondered if there was something in our genes that affected how well someone took to vegetarianism.

Researchers utilized data from the UK Biobank (a large-scale biomedical database), comparing the genetic profiles of 5,324 vegetarians who ate no meat, fish, or poultry to 329,455 control subjects. All subjects were taken from a homogenous sample of white Caucasian background to avoid ethnicity-related variables that might impact the results.

“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.” —Nabeel Yaseen, MD, PhD

Researchers found that there were three genes significantly associated with strict vegetarianism (and another 31 that had potential association). Two of the three significant genes were tied to fat metabolism and brain function within the body—making researchers hypothesize that how people metabolize fats plays a role in whether or not they’re able to stick with vegetarianism. “Lipid profiles of foods from animal sources are significantly different from those of plant sources,” the study authors wrote. Individuals with these specific “vegetarian” genes may be able to synthesize these lipid components internally without eating meat, the researchers hypothesized. Meanwhile, people without this genetic profile may need to eat meat-based products to obtain these essential fats, and thus would crave meat more significantly if they went without.

Caveat incoming: This is just the first study to make this potential connection. Lots more research needs to be done, particularly on people of different ethnic backgrounds, to know more definitively whether these three genes do play a role in vegetarianism. But there’s lots of interesting potential here to explore—and the results might bring some peace of mind to people who may feel guilty for having to give up their plant-based ways.

“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,” corresponding study author Nabeel Yaseen, MD, PhD, shared in a press release about the study.

Other factors that contribute to plant-based eating

Of course, your genetics aren’t everything. There are many other social and cultural reasons why someone may opt for a vegetarian or plant-based lifestyle, DNA be damned:

Religion and culture

There are cultures and religions across the globe where vegetarianism is a core tenant of daily life and practice. For example, Rastafarians in Jamaica follow a vegetarian diet by eating what they call Ital food: no salt, oil, and meat, and instead having lots of natural foods from the Earth. A whopping 24 percent of the Indian population is vegetarian, thanks to many of the prominent religions in the country that prioritize plant-based eating like Buddhism, Hinduism, and Jainism. But these examples are just scratching the surface, as several other religions and cultures across nearly every continent place importance on following a plant-based diet.

Environment and ethics

As concern surrounding climate change and animal welfare grows, so do commitments to eating fewer (or zero) meat-based products. This is partially related to the at least 14.5 percent of all global greenhouse gas emissions tied to raising livestock for meat. Another study found that global greenhouse gas emissions from animal foods are double that of plant-based foods³. Plus, many of the concentrated farming operations that pump out high volumes of animals for meat production are notorious polluters of local air and waterways through the dumping of chemicals, animal waste, and more. This negatively impacts the health of the surrounding communities and ecosystems.

On the ethics front, a staggering 80 billion animals are killed each year to meet the growing demand for meat products. Many animals, particularly those sourced from large-scale factory farm operations, are subject to cruel treatment during their short lifespans before being killed for meat. Workers in the meat processing and packing industries are also treated inhumanely⁴: paid low wages, subject to serious injuries, psychological distress⁵, and minimal protections. For many animal lovers, these realities have driven them towards a more plant-based lifestyle.

Health

And finally, we have health which is possibly the most popular reason why more and more people are reaching for meat alternatives. In fact, plant-based eating has been linked to reduced risk for heart disease⁶, cancer⁷, type 2 diabetes⁸, and kidney disease⁹. (It’s also associated with improved gut health¹⁰.)

One main through line on how a vegetarian lifestyle yields all these health benefits is through its general reduction of inflammation throughout the body. This is thanks to its generally boosted fiber, vitamin, mineral, and plant compound content. But on the other side of the coin, if plant-based diets aren’t practiced intentionally, they can put followers at risk for deficiencies in key vitamins and minerals that are harder to get from plants (like iron and vitamin B12).

The bottom line

Yes, scientists have found some genetic factors that might potentially make it easier for some people (and harder for others) to strictly follow a vegetarian diet. But there are so many other social and cultural elements at play that can override (or make less important) what’s written in your DNA. If you want to eat less meat but can’t quite fully go cold turkey (so to speak), the flexitarian way might be up your alley.

It’s also important to note that no one way of eating is going to be superior for everyone. If you strictly follow a plant-based lifestyle, that is wonderful. But if you don’t, take it from this dietitian: There’s no need to worry or feel shame. Any way of eating should still prioritize variety through including lots of different fruits, vegetables, nuts, seeds, legumes, whole grains, herbs, and spices to provide a wide array of nutrients.

Regardless of whether you’re plant-based or not (and your reasons why), embracing moderation and balance in both lifestyles is paramount to overall wellness.