Genetic Variant Discovered in Eskimos That Is Suitable for a Diet Rich in Omega-3

Eskimos: a Gene Makes Them Suited to a Diet Rich in Omega-3

Specific genetic mutations in the Inuit population, the indigenous people of Greenland, are associated with a particular metabolism of omega-3 fatty acids as well as other physical traits such as height and weight, revealing a genetic and physiological adaptation to a diet rich in polyunsaturated fatty acids.

This is reported in a fascinating new study published recently in the journal Science. The research was conducted by a group of researchers from the UK, USA, and Denmark.

A People Who Feed Almost Exclusively on Fish

The Inuit, indigenous to Greenland, have long lived in the extreme environmental conditions typical of the Arctic and follow a diet rich in proteins and fatty acids, particularly omega-3 EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). In 1970, a group of Danish researchers studying the metabolism of this population identified omega-3s in fish as having a protective effect against cardiovascular diseases, which were almost absent in the Inuit. These conclusions paved the way for many studies confirming this hypothesis and have led, for Western populations with diets low in omega-3, to current recommendations for adequate fish intake to prevent cardiovascular disease.

Inuit Genetically Adapted to a Diet Rich in Polyunsaturated Fatty Acids

In this new study, researchers analyzed the genetic profile of the Inuit and compared it with other populations. They discovered several genetic variants unusually common in this population compared to those from Europe or China. Many of these variants were found in a group of genes necessary for building enzymes called fatty acid desaturases, which contribute to determining omega-3 levels in the body. Specifically, the results suggest that the Inuit cannot convert short-chain omega-3s into long-chain omega-3s as other populations do, and they appear to counterbalance the high intake of long-chain omega-3s in their diet by converting them into short-chain forms. Furthermore, the data show that genetic variants of fatty acid desaturases have a strong effect on height and weight. By analyzing the membrane lipids of cells, the researchers found that genetic forms modulate the fatty acid composition of cell membranes, a factor that can also influence the regulation of hormones related to growth.

The Study Does Not Question the Positive Effects of Omega-3 in Other Populations

According to the authors of the study, these results demonstrate how the diet of a group of individuals can contribute to the genetic evolution of the population itself. As reported by researchers from the Global Organization for EPA and DHA (GOED), however, these results do not show that other peoples do not need EPA and DHA, as suggested by the New York Times, which raised doubts about whether omega-3 fats are truly protective for everyone’s health. Moreover, the study’s results do not contradict the over 3,000 clinical studies confirming the role of omega-3s in non-Inuit populations. Simply, the Eskimos metabolize the omega-3s they consume daily differently. The researchers plan to continue exploring the topic with further research. To stay updated on the latest scientific news about omega-3s, subscribe to our newsletter.

Source: Matteo Fumagalli et al. “Greenlandic Inuit show genetic signatures of diet and climate adaptation”. Science 18 September 2015: Vol. 349 no. 6254 pp. 1343-1347 DOI: 10.1126/science.aab2319