Eating less meat is good for your health and the environment. Now a new study suggests genes may play a role in people's ability to stick to a strict vegetarian diet.

Transcript

ARI SHAPIRO, HOST:

Lots of people who experiment with a vegetarian diet don't end up sticking with it, and a new study may help explain why. NPR's Allison Aubrey reports, when it comes to what we eat, we are influenced not only by our taste buds and culture - turns out our genetics play a role as well.

ALLISON AUBREY, BYLINE: There are different motivations for trying a vegetarian diet - from ethical and religious to potential health and environmental benefits. And like a lot of folks, Dr. Nabeel Yaseen of Northwestern University has tried giving up meat a few times. But he says it didn't last, which is a pretty common story, and he wanted to know why.

NABEEL YASEEN: The finding in this paper is that - yes, that these three genes have something to do with vegetarianism.

AUBREY: To study this, Dr. Yaseen used data from the U.K. Biobank to analyze the DNA of more than 300,000 people, including about 5,000 who were strict vegetarians and had not eaten any animal products in at least a year. They found a bunch of genes that may play a role.

YASEEN: What we can say is that these genes have something to do with vegetarianism, that perhaps vegetarians have different variants of these genes that make them able to pursue a strict vegetarian diet.

AUBREY: Dr. Yaseen and his colleague carried out what's known as a genome-wide association study to identify snips or tiny differences in people's DNA that are statistically associated with a particular trait - in this case, adhering to a strict vegetarian diet.

YASEEN: You are looking for - essentially, for markers in the genome. So we found one snip that is significantly associated with vegetarianism. And we look at - around, you know - what are the genes that are around it.

AUBREY: They found three genes most strongly associated with vegetarianism, and two of these have important functions in lipid or fat metabolism. The study can't answer exactly how they shape the trait of strict vegetarianism, but Dr. Yaseen has some ideas.

YASEEN: One hypothesis, which is highly speculative, is maybe there is a lipid nutrient in meat that some people need and others don't.

AUBREY: Of course, what we eat is shaped by a bunch of factors - from our taste preferences to our budgets and culture. And Dr. Yaseen says this is just the beginning of understanding the role of genetics.

Allison Aubrey, NPR News. Transcript provided by NPR, Copyright NPR.