My doctor had me on fish oil pills for quite a while — they were a popular supplement that was supposed to reduce the incidence of heart disease. She told me not to bother any more about a year ago, as more information was coming out that they didn’t really do anything. Now it looks like the original study that started the fish oil fad is falling apart.
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.
If you’re going to do a correlational study, you have to be fairly rigorous in exactly what you’re measuring: if you’re going to claim that Substance X has an effect on Disease Y, it’s kind of important that you’re actually measuring Disease Y. In this case, the correlation wasn’t what they claimed it was: it was more like, poverty-stricken indigenous populations with limited access to public health facilities poorly document their incidence of disease.
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 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.
This is almost as bad as the claim that the paleo diet must be good for you, because public health records from the paleolithic are even scantier than those for the Inuit.