A popular study from the 1970s that helps sell millions of dollars' worth of fish oil supplements worldwide is deeply flawed, according to a new study being published in the Canadian Journal of Cardiology.

A new study has found that 1970's research into the cardiovascular benefits of fish oil and omega-3 fatty acids was deeply flawed. (iStock) The original study, by Danish physicians H.O. Bang and D.J. Dyerburg, claimed Inuit in Greenland had low rates of heart disease because of their diet, which is rich in fish oil and omega-3 fatty acids from eating fish and blubber from whales and seals.

"I reviewed this original paper and it turned out to be that they actually never measured the frequency of heart disease in [Inuit]," said Dr. George Fodor, the new study's lead researcher.

"They relied upon some [public health records] in Greenland, and also relied on hearsay. People told them that [heart disease] was very rare," he said. "So this is very soft, from the point of view of science."

Public health records

Fodor and his team of three other researchers found that the chief medical officer's annual records were likely deficient because the inaccessible, rural nature of Greenland made it difficult to keep accurate records, and also because many people didn't have access to doctors.

The sale of fish oil supplements has grown into a global billion-dollar industry. (CBC) The 2014 study has found that Inuit do have similar rates of heart disease compared to non-Inuit populations, and that death rates due to stroke are "very high."

The study also shows that the Greenland Inuit overall mortality is twice as high as non-Inuit populations.

"Most of the researchers never read [the original 1970s] papers. They just took it at face value that what they said is so," Fodor said.

"The fish oil capsules I don't think will stand up to a critical review. They simply don't do anything for you," he said. "The people should know that it doesn't help to prevent heart disease."

Fodor said he's been contacted by media outlets around the world, despite the fact the paper won't be formally published by the Canadian Journal of Cardiology until later this summer. It's available online for now. Fodor, who recently retired from the University of Ottawa Heart Institute, started the study in 2013.