The Inuit, a group of culturally similar people native to Greenland and other Arctic regions in Canada and Alaska, are known for their low rates of heart disease and diabetes despite their high intake of marine animal fat, which includes high amounts of omega-3 fatty acids. In fact, it was the Inuit diet that initially led researchers to propose that omega-3s from fish may play an important role in protecting against heart disease. Since then, some—but not all—studies have indicated that the protective role of omega-3s is more limited than initially thought. Now, NPR has reported on a study that adds a new perspective on the omega-3–heart disease debate: the Inuit may have genetic adaptations that contribute to their ability to balance the levels of omega-3 and omega-6 fats in their bodies. Published in the journal Science, the study looked at 191 Greenlandic Inuit with less than 5% European ancestry, 60 individuals of European ancestry, and 44 individuals of Han Chinese ancestry. The researchers discovered that nearly all of the Inuit had genetic variants that limited their body’s production of certain types of omega-3 and omega-6 fats. Only about 3% of the Europeans and 15% of the Chinese in the study had the same genetic variants. Interestingly, these variants were also strongly associated with height—having the mutations was associated with a reduction of height by almost an inch.
Nevertheless, an important question still remains: did these genes evolve to handle large amounts of fats (including omega-3s) in the Inuit diet, or did they evolve in response to some other environmental condition? It’s difficult to understand all of the different effects of these particular genes, as they play a role in multiple processes throughout the body. It’s also important to note that the study did not specifically address the relationship between the gene mutations, omega-3s, and heart disease. There is still good evidence to suggest that, in the absence of a seafood-rich diet, supplementing with fish oil may still offer important health benefits.