The Inuit have unique genetic mutations affecting metabolism that allows them to neutralize the harmful effects of a high fat diet of marine mammals, their main food source, researchers have discovered.
Nearly 100% of Inuit have these genetic variations compared to 2% for Europeans and 15% among ethnic Han Chinese, they determined in this research published Thursday in the journal Science.
Besides whale meat and seal, these people also consume large quantities of fish from which the oil is rich in omega-3 fatty acids.
“It is very good for the Inuit to consume a lot of these omega-3 fatty acids but not for the rest of us.”
professor of biology at the University of California at Berkeley
Despite this traditional diet very low in fruits and vegetables and high in animal fat, Inuit are generally healthy with a low incidence of cardiovascular disease, had already found Danish researchers in the 70s.
They then concluded that omega-3 should have protective effects to explain this paradox.
The benefits of omega-3 are not confirmed
These findings are causing recommendations in Europe and the rest of the world to consume more fatty fish or taking supplements of omega-3 to help maintain a healthy heart and arteries, says Rasmus Nielsen, a professor of biology at the University of California at Berkeley, one of the authors of this new study.
Today, at least 10% of Americans regularly take these supplements. But the results of recent clinical trials have not confirmed the cardiovascular benefits of omega-3, or to protect against Alzheimer’s disease.
“We found that the Inuit have a unique genetic adaptation to diet that can not be extrapolated to other ethnic groups,” says the scientist. Thus, “it is very good for the Inuit to consume a lot of these omega-3 fatty acids but not for the rest of us,” he concludes.
These genetic mutations have even wider effects such as reducing the bad cholesterol (LDL) and blood sugar which has protective effects against cardiovascular disease and adult diabetes (type 2).
These genetic characteristics also affect the size because the growth is in part regulated by fat metabolism. For Inuit, these mutations reduce their size of two centimeters, researchers have determined.
They have discovered these genetic mutations by analyzing the genomes of 191 Groenlandais with less than 5% of European genes they were compared with those of 60 and 44 Europeans Chinese ethnic Han.
According to these scientists these genetic mutations to date back at least 20,000 years old and may have helped many peoples as human hunter-gatherers to adapt to diets high in animal fat and certain types of omega-3 fatty acid omega-6.
They might have appeared initially among Siberians living in the Arctic there are more than 20,000 years. And they arrived in Greenland where the Inuit have settled there about a thousand years.
This genetic selection is old and could have helped humans adapt to the environment during the last ice age, but was significantly higher among the Inuit, the researchers believe.