Vegetarian Diet may Increase the Risk of Cancer and Heart Disease

Long-term vegetarianism may lead to a genetic mutation that increases the risk of heart disease and cancer, says a new research. The study found a particular mutation in a primarily vegetarian population in Pune, India.

Researchers from Cornell University in the US compared the Indian group to a group of meat-eating Americans from Kansas. By using data from the 1000 Genomes Project, researchers found that the vegetarian diet over many generations may have driven the higher frequency of a mutation in the Indian population.

‘A genetic mutation occurs in long-term vegetarians to absorb essential fatty acids. This boosts the production of arachidonic acid that raises the risk of cancer and inflammatory diseases.’

The mutation (called rs66698963 and found in the FADS2 gene) is an insertion or deletion of a sequence of DNA that regulates the expression of two genes, FADS1 and FADS2.These two genes control the production of fatty acids in the body.

Among the long chain fats, arachidonic acid is a key target of the pharmaceutical industry because it is a central culprit for those at risk of heart disease, colon cancer and many other inflammation-related conditions.

The mutation was found mainly in populations eating vegetarian diets and do not have foods that are rich in polyunsaturated fats such as fatty fish. However, the deletion of the same sequence might have been adaptive in populations which are based on marine diets, such as the Greenlandic Inuit.

To better understand the mutations and these genes as a genetic marker for disease risk, the authors will have to study the additional worldwide population.

Dr. Tom Brenna, and Dr. Kumar Kothapalli, said, "With little animal food in the diet, the long chain polyunsaturated fatty acids must be made metabolically from plant PUFA precursors. The physiological demand for arachidonic acid, as well as omega-3 EPA and DHA, in vegetarians, is likely to have favored genetics that supports the efficient synthesis of these key metabolites."

"Changes in the dietary omega-6 to omega-3 balance may contribute to the increase in chronic disease seen in some developing countries."

Dr. Alon Keinan, said, "Several previous studies pointed to recent adaption in this region of the genome. Our analysis points to both previous studies and our results being driven by the same insertion of a small additional piece of DNA, an insertion which has a known function."

"We showed this insertion to be adaptive, hence of high frequency, in Indian and some African populations, which are vegetarian. However, when it reached the Greenlandic Inuit, with their marine diet, it became maladaptive."

The study was published in the journal Molecular Biology and Evolution.

Source: Medindia