"The message for vegetarians is simple. Use vegetable oils that are low in omega-6 linoleic acid such as olive oil." This is the advice of Dr Tom Brenna, Professor of Human Nutrition at Cornell University, USA. Long term vegetarianism can lead to genetic mutations that raise the risk of heart disease and cancer, scientists have found.
The team 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.
Populations who have had a primarily vegetarian diet for generations were found to be far more likely to carry DNA that makes them susceptible to inflammation. The researchers believe that the mutation occurred to make it easier for vegetarians to absorb essential fatty acids from plants. But it has also the effect of boosting the production of arachidonic acid, which is known to increase 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.
To make the problem worse, the mutation also hinders the production of beneficial omega 3 fatty acid which is protective against heart disease.
The finding may help explain previous research which found vegetarian populations are nearly 40 per cent more likely to suffer colorectal cancer than meat eaters, a finding that has puzzled doctors because eating red meat is known to raise the risk.