A study of Yup'ik Eskimos in Alaska, who on average consume 20 times more omega-3 fats from fish than people in the lower 48 states, suggests that a high intake of these fats helps prevent obesity-related chronic diseases such as diabetes and heart disease.
The study, 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, was published online March 23 in the European Journal of Clinical Nutrition.
"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 U.S. population, this offered a unique opportunity to study whether omega-3 fats change the association between obesity and chronic disease risk," said lead author Zeina Makhoul, Ph.D., a postdoctoral researcher in the Cancer Prevention Program of the Public Health Sciences Division at the Hutchinson Center.
The fats the researchers were interested in measuring were those found in salmon, sardines and other fatty fish: docosahexaenoic acid, or DHA, and eicosapentaenoic acid, or EPA.
Researchers analyzed data from a community-based study of 330 people living in the Yukon Kuskokwim Delta region of southwest Alaska, 70 percent of whom were overweight or obese. As expected, the researchers found that in participants with low blood levels of DHA and EPA, obesity strongly increased both blood triglycerides (a blood lipid abnormality) and C-reactive protein, or CRP (a measure of overall body inflammation). Elevated levels of triglycerides and CRP increase the risk of heart disease and, possibly, diabetes.
"These results mimic those found in populations living in the Lower 48 who have similarly low blood levels of EPA and DHA," said senior author Alan Kristal, Dr. P.H., a member of the Hutchinson Center's Public Health Sciences Division. "However, the new finding was that obesity did not increase these risk factors among study participants with high blood levels of omega-3 fats," he said.
"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 Eskios from some of the harmful effects of obesity."
While Yup'ik Eskimos have overweight/obesity levels similar to those in the U.S. overall, their prevalence of type 2 diabetes is significantly lower – 3.3 percent versus 7.7 percent.
"While genetic, lifestyle and dietary factors may account for this difference," Makhoul said, "it is reasonable to ask, based on our findings, whether the lower prevalence of diabetes in this population might be attributed, at least in part, to their high consumption of omega-3-rich fish."
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 for three consecutive days. Height, weight, percent body fat, blood pressure and physical activity were also measured.
The median age of the participants was 45 and slightly more than half were female. The women were more likely than the men to be heavy, and body mass index (height-to-weight ratio) for all increased with age.
"Residents of Yup'ik villages joined this research because they were interested in their communities' health and were particularly concerned about the health effects of moving away from their traditional ways and adopting lifestyle patterns similar to those of residents in the lower 48 states," Makhoul said.
Based on these findings, should overweight and obese people concerned about their chronic disease risk start popping fish oil supplements or eat more fatty fish?
"There are good reasons to increase intake of fatty fish, such as the well-established association of fish intake with reduced heart disease risk," Makhoul said. "But we have learned from many other studies that nutritional supplementation at very high doses is more often harmful than helpful."
Before making a public health recommendation, the researchers said that a randomized clinical trial is needed to test whether increasing omega-3 fat intake significantly reduces the effects of obesity on inflammation and blood triglycerides.
"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," she said.
The National Center for Research Resources, and the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health funded the study, which also involved investigators from the University of California-Davis.
At Fred Hutchinson Cancer Research Center, our interdisciplinary teams of world-renowned scientists and humanitarians work together to prevent, diagnose and treat cancer, HIV/AIDS and other diseases. Our researchers, including three Nobel laureates, bring a relentless pursuit and passion for health, knowledge and hope to their work and to the world. www.fhcrc.org
Kristen Woodward | EurekAlert!
WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf
First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences