A study of Alaska's Yup'ik Eskimos, who consume 20 times more omega-3 fats from fish than most Americans, suggests these oils can prevent obesity-related illness such as diabetes and heart disease, researchers said Friday.
The researchers analyzed data from 330 people living in the Yukon Kuskokwim Delta region of southwest Alaska.
Although 70 percent of the population was overweight or obese, they did not show the same risk factors for heart disease and had a lower prevalence of diabetes than the overall US population.
The fats the researchers were interested in measuring were those found in salmon, sardines and other fatty fish -- docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
In participants with low blood levels of these fats, obesity strongly increased heart disease risk measured by triglycerides and C-reactive protein, a measure of overall body inflammation.
Additionally, the researchers said that although the Yup'ik Eskimos have overweight/obesity levels similar to those in the US overall, their prevalence of type 2 diabetes is significantly lower -- 3.3 percent versus 7.7 percent.
"Because Yup'ik Eskimos have a traditional diet that includes large amounts of fatty fish and have a prevalence of overweight or obesity that is similar to that of the general US population, this offered a unique opportunity to study whether omega-3 fats change the association between obesity and chronic disease risk," said Zeina Makhoul, a researcher at the Fred Hutchinson Cancer Research Center and lead author.
"Interestingly, we found that obese persons with high blood levels of omega-3 fats had triglyceride and CRP concentrations that did not differ from those of normal-weight persons," Makhoul said.
"It appeared that high intakes of omega-3-rich seafood protected Yup'ik Eskimos from some of the harmful effects of obesity."
The study was led by researchers at Fred Hutchinson Cancer Research Center and conducted in collaboration with the Center for Alaska Native Health Research at the University of Alaska-Fairbanks. It published online March 23 in the European Journal of Clinical Nutrition.
For the study, the participants provided blood samples and health information via in-person interviews and questionnaires. Diet was assessed by asking participants what they ate in the past 24 hours and asking them to keep a food log.
The researchers said however that further studies would be needed to make specific recommendations on diets or supplements.
"If the results of such a trial were positive, it would strongly suggest that omega-3 fats could help prevent obesity-related diseases such as heart disease and diabetes," Makhoul said.