Fish oil may not be a defence against heart disease, research shows
Long-held scientific claims that omega-3 defends against heart disease may have been flawed, writes Sasha Gonzales
You've probably heard about the heart benefits of oily fish - consume salmon, sardines, mackerel or tuna a couple of times a week as part of a balanced diet, and you'll be doing your heart a favour. Fish oil supplements, which are also rich in heart-healthy omega-3 fatty acids, are the next best thing if you can't stand eating fish.
This dietary guideline isn't new. It is based in part on a study by two Danish physicians, Hans Olaf Bang and Jorn Dyerberg in the 1970s, which revealed that the low incidence of coronary artery disease (CAD) among the Greenland Inuits was linked to the group's high consumption of marine fats like whale and seal blubber.
But when some researchers recently set out to re-examine the validity of Bang and Dyerberg's famous study, they noted that it was flawed, according to their findings, which were published in the Canadian Journal of Cardiology.
The heart health of the Greenland Inuits had not actually been investigated, so there was no evidence to back claims that a diet high in fish oils does indeed provide cardio-protective benefits. In fact, the typical Inuit diet - which was high in animal fats and low in fruits and vegetables - violated all principles of balanced and heart-healthy nutrition.
In reviewing the original Bang and Dyerberg study, lead investigator and cardiologist Dr George Fodor found that, "Inuits have a similar prevalence of CAD as non-Inuit populations, they have excessive mortality due to cerebrovascular strokes, their overall mortality is twice as high as that of non-Inuit populations, and their life expectancy is approximately 10 years shorter than the Danish population".
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According to Fodor, who is also head of research for the Prevention and Rehabilitation Centre at the University of Ottawa Heart Institute, the fact that Bang and Dyerberg overlooked important details is a big deal because, for the past 40 years, their study has been blindly accepted by doctors, nutritionists and other health experts as gospel truth.