A Cornell University study has found that the vegetarian diet has caused a genetic mutation in populations that have eaten the diet for hundreds of years, which allow them to metabolise omega-3 and omega-6 fatty acids more efficiently. As a result, if people with this vegetarian genetic variation deviate from their usual diet, they are more likely to suffer from inflammation, heart disease and colon cancer.
The researchers detected the mutation called rs66698963 in populations that historically favoured plant-based diets such as some people in Africa, some regions in East Asia and especially in India. The study published on March 29 in the journal Molecular Biology and Evolution cites that 70 percent of people from Pune in India have this gene variation.
The researchers investigated 234 primarily vegetarian Indians and 311 US citizens. The vegetarian gene was only found in 18 percent of US citizens. Moreover, the 1,000 Genomes Project reveals that the vegetarian gene is also found in 70 percent of South Asians, 53 percent of Africans, 29 percent of East Asians and in 17 percent of Europeans.
The plant-based diet altered the DNA sequence and this mutation can be found in the FADS2 gene which uses the omega-3 and omega-6 fatty acids for brain development and inflammation prevention. The vegetarian gene has an insertion of 22 bases, the building blocks of DNA, within the gene.
A different version of this genetic mutation can be found in the Inuit populations of Greenland. The same vegetarian genetic variation was not found in them since their diet was mainly marine-based and was rich in omega-3, making the benefit of the vegetarian gene unnecessary and even harmful.
In the same way, Northern Europeans have adapted to absorb enough nutrients from milk to metabolise fatty acids due to hundreds of years of drinking milk. This allowed them to get enough nutrients without the need for consuming too much milk.
The researchers believe that these findings may help pave the way for treatments of heart disease, colon cancer and other diseases related to inflammation that focus on the gene. This could also lay the foundation for personalised nutrition, which uses the genomic information to customise the diet.
Nevertheless, they suggest that more studies on worldwide populations must be conducted to gather more insight about the mutation. Moreover, the researchers admit that they do not know exactly when this mutation happened.
“It is possible that in the history of human evolution, when people migrated to different environments, sometimes they ate a plant-based diet and sometimes they ate a marine-based diet, and in different time periods these different alleles were adaptive,” co-lead author Kaixiong Ye says.