How Diet affected Genes

The tendency to vegetarianism is inherent in the genes, and it is better not to resist it

Ivan Zagorsky, Vesti

The food preferences of different peoples of the world vary greatly. For example, vegetarianism is traditionally developed in many countries of Asia and Africa, while in island states and in the Far North, fish and seafood have been the basis of the diet for centuries. Scientists from Cornell University have found out that the nutrition of our ancestors through genetic mechanisms continues to affect the health of modern people.

Researchers have discovered a gene whose different variants (alleles) favor a vegetarian diet in the population of India and a number of countries of the Asian and African continents or are adapted to a fish diet in the indigenous population of Greenland.

Elon Keinan and his colleagues compared the genes of the predominantly vegetarian population of the Indian city of Pune with the genes of residents of the American state of Kansas, who are famous for their love of beef. As a result, scientists discovered a mutation in the Indian version of the FADS2 gene associated with fatty acid metabolism.

Having found out this, the researchers began to look for similar mutations in people from different regions of the world and found its clear connection with long-standing vegetarian traditions. At the same time, there were no traces of mutation in the genes of the Inuit inhabiting Alaska, Northern Canada and Greenland, who have been feeding on fish and other seafood for centuries.

As it turned out, the "vegetarian" version of the gene makes it possible to enhance the synthesis of FADS1 and FADS2 enzymes in the body, which help more efficiently process omega-3 and omega-6 fatty acids of plant origin into compounds necessary for normal early brain development.

At the same time, it turned out that in people who, contrary to the traditions of their people, consume a lot of meat and change the balance of fatty acids in the diet, the same gene makes them more susceptible to inflammation and leads to an increased risk of developing cardiovascular diseases and colon cancer.

Fatty acids in meat and fish do not require such complex processing, therefore, the need for FADS1 and FADS2 enzymes is much lower among people who consume a large amount of animal products.

Analysis of a large number of genomes showed that the "vegetarian" version of the gene was present in 68% of Indians, 70% of South Asians, 50% of Africans, 29% of East Asians, 18% of Americans and 17% of Europeans.

"This is the most unique scenario of local genetic adaptation, in the discovery of which I was lucky enough to take part," says Keinan. – Our analysis shows that adaptation consists in adding a small fragment of DNA with functions known to us. In the case of the Greenland Inuit and their marine diet rich in omega-3 fatty acids, this option could become harmful and became unnecessary."

The results of the study, published in the journal Molecular Biology and Evolution (Kothapalli et al., Positive selection on a regulatory insertion-deletion polymorphism in FADS2 influences apparent endogenous synthesis of arachidonic acid), hint that based on genetic information, it is possible to personally adapt a person's diet to the variant that is embedded in his genes.

Now the team is trying to find out when the adaptation to the vegetarian type of food first occurred. So far, researchers have not found the corresponding alleles in the genomes of great apes, but their traces can be traced in the DNA of early hominids – Neanderthals and Denisovans. It is quite possible that the mutation developed when people settled on the planet and their food preferences changed depending on the conditions in which this or that group fell.

Portal "Eternal youth" http://vechnayamolodost.ru  30.03.2016