New study in the Canadian Journal of Cardiology questions the validity of original Bang and Dyerberg study; finds Eskimos have coronary artery disease at the same rate as other populations
Oily fish are currently recommended as part of a heart healthy diet. This guideline is partially based on the landmark 1970s study from Bang and Dyerberg that connected the low incidence of coronary artery disease (CAD) among the Eskimos of Greenland to their diet, rich in whale and seal blubber.
Now, researchers have found that Eskimos actually suffered from CAD at the same rate as their Caucasian counterparts, meaning there is insufficient evidence to back Bang and Dyerberg's claims. Their findings are published in the Canadian Journal of Cardiology.
Using 40 years of new information and research, a team of investigators set out to reexamine Bang and Dyerberg's study of Greenland Eskimos and CAD. This study is still widely cited today when recommending the dietary addition of fish oil supplements (like omega-3 fatty acids) or oily fish to help avoid cardiovascular problems.
However, the new review of information has determined that Bang and Dyerberg failed to actually investigate the cardiovascular health of the Eskimo population, meaning that the cardioprotective effects of their diet are unsubstantiated.
"Bang and Dyerberg's seminal studies from the 1970s are routinely invoked as 'proof' of low prevalence of CAD in Greenland Eskimos ignoring the fact that these two Danish investigators did not study the prevalence of CAD," notes lead investigator George Fodor, MD, PhD, FRCPC, FAHA. "Instead, their research focused on the dietary habits of Eskimos and offered only speculation that the high intake of marine fats exerted a protective effect on coronary arteries."
Bang and Dyerberg relied mainly on annual reports produced by the Chief Medical Officer of Greenland to ascertain CAD deaths in the region. The 2014 study has identified a number of reasons that those records were likely insufficient, mainly that the rural and inaccessible nature of Greenland made it difficult for accurate records to be kept and that many people had inadequate access to medical personnel to report cardiovascular problems or heart attacks.
In fact, researchers have now found that concerns about the validity of Greenland's death certificates have been raised by a number of different reports and that at the time, more than 30% of the population lived in remote outposts where no medical officer was stationed. This meant that 20% of the death certificates were completed without a doctor having examined the body.
The data collected through this new investigation shows that Eskimos do have a similar prevalence of CAD to non-Eskimo populations, and in fact, they have very high rates of mortality due to cerebrovascular events (strokes). Overall, their life expectancy is approximately 10 years less than the typical Danish population and their overall mortality is twice as high as that of non-Eskimo populations.
"Considering the dismal health status of Eskimos, it is remarkable that instead of labeling their diet as dangerous to health, a hypothesis has been construed that dietary intake of marine fats prevents CAD and reduces atherosclerotic burden," remarks Dr. Fodor.
Many recent large and well-designed studies have shown ambiguous or negative results regarding the cardioprotective properties of omega-3 fatty acids and fish oil supplements, and yet partly based on the work of Bang and Dyerberg, they are still widely recommended as part of a heart healthy diet plan.
"Publications still referring to Bang and Dyerberg's nutritional studies as proof that Eskimos have low prevalence of CAD represent either misinterpretation of the original findings or an example of confirmation bias," concludes Dr. Fodor.
"To date, more than 5000 papers have been published studying the alleged beneficial properties of omega-3 fatty acids, not to mention the billion dollar industry producing and selling fish oil capsules based on a hypothesis that was questionable from the beginning."
Eileen Leahy | Eurek Alert!
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences