"What about the Eskimos?" The question is often raised to challenge those who hold that a plant-based diet is best for the heart and for health overall. The idea is that a diet of fish and blubber -- not vegetables and fruits -- has kept Arctic natives free of heart disease. A new study, published in the Canadian Journal of Cardiology, suggests that the myth is, in fact, a myth.
The "fish and blubber are healthy" notion began in the 1970s, when Danish physicians Hans Olaf Bang and Jorn Dyerberg visited an area of Greenland north of the Arctic Circle and suggested that such a diet reduced the risk of cardiovascular disease among the native populations. In response, sales of fish oil supplements took off, and nutrition authorities began to promote the cardiovascular benefits of oily fish.
Controlled studies, however, failed to show benefits of fish oil. In a 2012 report in the Journal of the American Medical Association, researchers compiled the results of 20 studies including 68,680 patients, finding that fish oil had no effect on heart-related deaths, heart attacks, or strokes. A second 2012 report showed that fish oil did not prevent the recurrence of heart problems. In 2013, the New England Journal of Medicine published the results of a study including 12,513 men and women, showing that fish oil supplements did nothing to prevent heart disease deaths or hospitalizations. Two more studies that year showed that fish oil did nothing for cognition and may increase risk of prostate cancer.
In the latest study, researchers at the University of Ottawa Heart Institute took a fresh look at the original Greenland studies that started the myth. It turned out that Bang and Dyerberg did not study the native populations directly. Rather, they relied on death reports and hospital admission figures, which, in rural areas, turned out to be less than reliable.
In fact, data collected over many decades showed that coronary artery disease is common in Greenland's Inuit population. Heart disease is as frequent -- or even more so -- among native northern populations as it is for other populations. Strokes are particularly common, and life expectancy overall was found to be about a decade shorter among native populations.
The best estimates suggest that a diet emphasizing fish and blubber is, if anything, harmful for heart health. Northern natives pay an unfortunate price for the lack of availability of healthful foods.