It turns out, those amazing claims about the heart health benefits of fish oil and omega 3 fatty acids weren't wrong. They were just off base and it turns out that benefits are likely only realized in people whose bodies have adapted to processing the healthy fat, according to a study published in the journal Science last Friday.
The Inuit, Greenland's native people, ate what the sea and tundra would give them: some seals, some whales, a few berries and a ton of fish. Over time, the Inuit adapted to their arctic digs and their physiology changed as well -- they became shorter and thinner.
The study was conducted by researchers from the University of California Berkeley, Greenland and Denmark who analyzed the genomes of 161 Greenlanders and compared them to those of 60 Europeans.
After analysing membrane lipids, the team of scientist concluded that a group of alleles, alternative forms of genes, was modulating the fatty acid make up of the Inuit.
The researchers found that "have found signs of selection for genetic variants in fat metabolism, not just for promoting heat-producing brown fat cells but also for coping with the large amounts of polyunsaturated fatty acids found in their seafood diet," according to the study's editor.
The findings are some of the most conclusive evidence that populations of people have adapted for specific diets, according to Rasmus Nielsen, leader of the project and a professor of integrative biology at UC Berkeley.
"People ask themselves whether they should be on a Stone Age diet, for example," said Nielsen. "The response may well depend on their genome."
Interest in omega-3 fatty acids originally came from research into the Inuit, Nielsen pointed out. The Inuit seem to have a relatively low occurrences of heart disease, which ran counter intuitive to their heavy intake of fat, he said.
"We've now found that they have unique genetic adaptations to this diet, so you cannot extrapolate from them to other populations," Nielsen said. "A diet that is healthy for the Inuit may not necessarily be good for the rest of us."