'Vegetarian gene' linked to heart disease and cancer risk, scientists find

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Populations with vegetarian diets have a gene which can raise the risk of heart disease and cancer, scientists believe.

US researchers have found that people who have lead vegetarian lifestyles for generations in areas of India, Africa and East Asia have evolved a “vegetarian gene” variation, or allele.

The gene identified by scientists at Cornell University helps those who eat plant-based diets to process omega-3 and omega-6 fatty acids into compounds that help the development of the brain and control inflammation in the body.

Scientists found a similar gene variation for fish in Inuit populations of Greeland, where seafood is a staple of the diet.

However, the vegetarian gene variation could also cause a spike in the production of arachidonic acid, which makes the body prone to inflammation and has been linked to heart disease and cancer, The Telegraph reported.

This can be harmful if a person with the gene has a diet high in certain vegetable oils, such as sunflower oil, as the body will metabolise the fatty acids into arachidonic acid more quickly.

Tom Brenna, Professor of Human Nutrition at Cornell, told The Telegraph that: “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.

Dr Brenna said this may be one factor why populations in developing countries with diets high in plant-based foods have chronic diseases.

He added that vegetarians who are concerned should use vegetables oils low in omega-6 linoleic acid, such as olive oil.

The researchers made their findings, published in the journal ‘Molecular Biology and Evolution’, by analysing the presence of the vegetarian allele in 234 primarily vegetarian Indians and 311 people from the US who followed the country's standard diet. They found the allele in 68 per cent of the Indian people, and 18 per cent of Americans.

This data was assessed alongside data from the 1,000 Genomes Project, which found that 70 per cent of South Asians, 53 per cent of Africans, and 29 per cent of East Asians and 17 per cent of Europeans, where the diet is largely meat and starch.

“Northern Europeans have a long history of drinking milk and they absorbed enough end products from milk for long-chain fatty acid metabolism so they don’t have to increase capacity to synthesize those fatty acids from precursors,” said Kaixiong Ye, co-lead author of the paper.

A recent study by researchers at the University of Oxford found that millions of lives could be saved annually by the year 2050 if people adopt vegetarian diets.

Dr Marco Springmann, lead author of the study conducted at the Oxford Martin Programme on the Future of Food, highlighted that a person’s diet “greatly influences” their health and the global environment.

“Imbalanced diets, such as diets low in fruits and vegetables, and high in red and processed meat, are responsible for the greatest health burden globally and in most regions,” he said.