Populations who have had a primarily vegetarian diet for generations carry a genetic mutation which significantly raises the risk of cancer and heart disease, a new study has found.
According to the latest issue of Molecular Biology and Evolution, populations who have a “traditional plant-based diet practice” were found to be far more likely to carry DNA which makes them susceptible to these diseases.
The study, titled “Positive selection on a regulatory insertion-deletion polymorphism in FADS2 influences apparent endogenous synthesis of arachidonic acid,” and published online in the March issue of Molecular Biology and Evolution, shows that the genetic mutation occurred to make it easier for vegetarians to absorb fatty acids from plants.
However, this adaptation has had the additional effect of boosting the production of arachidonic acid, which causes increased inflammatory disease and cancer.
When coupled with a diet high in vegetable oils—such as sunflower oil—the mutated gene quickly turns fatty acids into dangerous arachidonic acid.
The findings explain previous research which found vegetarian populations are nearly 40 percent more likely to suffer colorectal cancer than meat eaters.
Researchers from Cornell University in the US compared hundreds of genomes from a primarily vegetarian population in Pune, India to traditional meat-eating people in Kansas and found there was a significant genetic difference.
“Those whose ancestry derives from vegetarians are more likely to carry genetics that more rapidly metabolize plant fatty acids,” said Tom Brenna, Professor of Human Nutrition at Cornell.
“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 mutation appeared in the human genome long ago, and has been passed down through the human family.”
To make the problem worse, the mutation also hinders the production of beneficial Omega 3 fatty acid which is protective against heart disease.
The mutation is called rs66698963 and is found in the FADS2 gene which controls the production of fatty acids in the body.
A 2014 study found that vegetarianism and veganism also cause significantly lower sperm counts.
Many vegetarians struggle to get enough protein, iron, vitamin D, vitamin B12, and calcium which are essential for health. One study found that vegetarians had approximately 5 percent lower bone-mineral density (BMD) than non-vegetarians.