A study linking a long-term vegetarian diet to DNA mutations that raise heart disease and cancer risks should not encourage anyone to ditch fruits and vegetables.
However, it raises intriguing questions and should lead to further research, said Judith Hiemenga, MD, a Spectrum Health genetic specialist.
The research examines the broad issue of population genetics―not the impact of whether you choose a salad or hamburger for lunch.
“You don’t get genetic mutations because this is what you’re eating. That doesn’t induce mutations,” Dr. Hiemenga said.
Cornell University scientists found a population with a primarily vegetarian diet carried a much higher rate of a DNA mutation that makes people more susceptible to inflammation. That mutation, combined with a diet high in vegetable oils, may increase the risk of heart disease and colon cancer.
The researchers based their findings on a comparison between the primarily vegetarian population in Pune, India, and a traditional meat-eating population in the U.S., made up of mostly Kansans.
Genetic adaptations often carry negative effects, along with the beneficial ones.
Dr. Hiemenga cited the genetics of sickle cell disease. Those who carry a single copy of the gene―and generally do not develop the disease―have shown a resistance to malaria. As a result, sickle-cell carriers are more common in areas where malaria spreads.
“They are more likely to live and be healthy and have children and be able to support their children,” she said.
Similarly, the genetic mutation studied by the Cornell scientists may help people thrive on a vegetarian diet. The researchers say the mutation may make it easier for vegetarians to absorb fatty acids from plants.
“Those whose ancestry derives from vegetarians are more likely to carry genetics that more rapidly metabolize plant fatty acids,” Cornell Professor Tom Brenna said in a report by the Telegraph.
“In such individuals, vegetable oils will be converted to the more pro-inflammatory arachidonic acid, increasing the risk for chronic inflammation that is implicated in the development of heart disease, and exacerbates cancer.”
The study opens the door to further investigation, Dr. Hiemenga said. It’s possible the population carries a predisposition for disease unrelated to the genetic mutation.
“Is this something that’s real and do we need to be aware of this? Or is this a fluke in this particular study?” she said. “Once you raise the question, you will have more researchers addressing this―confirming this or refuting it.”
The study appears online in the journal Molecular Biology and Evolution.