Genetic variant found in Eskimos suitable for omega-3-rich diet

Eskimos: one of their genes makes them suitable for an omega-3-rich diet

Specific genetic mutations in the Inuit, an indigenous people of Greenland, are associated with a particular omega-3 fatty acid metabolism and also with other physical characteristics 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 in the journal Science just these days. The research was conducted by a group of British, American and Danish researchers.

A people who feed almost exclusively on fish 

The Inuit, indigenous people of Greenland, have long lived in the extreme environmental conditions typical of the Arctic and eat a diet rich in protein and fatty acids, particularly the omega-3 EPA (eicopentaenoic acid) and DHA (docosahexaenoic acid). In 1970 a group of Danish researchers studying the metabolism of this population identified the omega-3 present in fish as having a protective effect against cardiovascular disease, which was almost absent in the Inuit. These conclusions paved the way over the years for numerous studies that confirmed this hypothesis and led, for Western peoples with a diet low in omega-3, to the current recommendations on the 'intake of the right amounts of fish, for the prevention of cardiovascular disease.

Inuit are genetically adapted to a diet rich in polyunsaturated fatty acids

In this new study, researchers analyzed the genetic profile of the Inuit by comparing it with that of other populations. They discovered several genetic variants that were unusually common in this population compared with those in Europe or China. Many of these variants were found in a group of genes required for building enzymes called fatty acid desaturase, which help determine omega-3 levels in the body. Specifically, the results suggest that the Inuit cannot convert short-chain omega-3s to long-chain omega-3s as well as other peoples, and would appear to counteract the high intakes of long-chain omega-3s in their diets by converting to short-chain ones. In addition, the data show that genetic variants in fatty acid desaturase have a strong effect on height and weight. By also analyzing cell membrane lipids, the researchers found that gene forms modulate the fatty acid composition of cell membranes, a factor that may also influence the regulation of growth-related hormones.

Study does not question positive action of omega-3s in other populations

According to the authors who directed the research, these results showed how the diet of a group of individuals can contribute to the genetic evolution of the population itself. As reported by the Global Organization for EPA and DHA (GOED) scholars, however, these results do not show that other peoples do not need EPA and DHA, as speculated by the New York Times, which raises doubts as to whether omega-3 fats are really protective of everyone's health. furthermore, the research findings do not contradict the more than 3,000 clinical studies that have confirmed the role of omega-3s in non-Inuit populations. Simply, Eskimos may metabolize omega-3s taken daily differently. In this regard, researchers plan to continue exploring the topic with new research. To stay up to date with the latest news from Omega-3 scientific research, write to our newsletter. 

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