In a randomized controlled trial studying fish oil versus placebo, a very modest improvement in heart health markers was observed in people prescribed fish oil. This TIME article demonstrates a good understanding of the study’s novelty, which appears to be among the first to look at potential benefits of fish oil in patients who have just had a heart attack.
However, the story missed the mark in several ways: It didn’t mention the potential harms of taking fish oil if you’re a post-heart attack patient, nor did it discuss costs of the intervention. The only person quoted is the lead researcher of the study–an independent source was needed. Lastly, several limitations of the study are not discussed, including that many patients did not return for post-treatment follow-up.
Fish oil is a widely used health supplement. Notwithstanding dozens of rigorous studies that cast doubt on its actual health benefits, the popularity of fish oil supplements remains unabated. Most studies have looked at the preventive benefits of fish oil in high-risk populations. The study reported here, on the other hand, examines the protective benefits of fish oil in patients right after a heart attack.
The results suggest that high doses of fish oil after a heart attack may have modest benefits, based on measurements of things like scarring and heart function, which are surrogate markers. News coverage ideally points out this fact–that these markers can’t tell us if fish oil actually reduces the risk of a repeat heart attack, death or other cardiac event.
Costs of the intervention are not disclosed. A casual reading of the news article may lead one to believe that over-the-counter fish oil was used in the treatment arm of the study. However, our own careful reading of the original study reveals that GlaxoSmithKline (Research Triangle Park, NC) provided both the fish oil and placebo pills. (The study was solely funded by the National Institutes of Health.)
A curious reader might ask what is the cost discrepancy between the fish oil by GlaxoSmithKline and a standard over-the-counter fish oil product, too.
The story includes the most salient quantitative evidence of the study:
This is sufficient for a Satisfactory rating. However, more context would have made the story stronger: That researchers don’t know what “6% less scarring” means in terms of actually reducing a repeat heart attack, death or another cardiac event.
And from the original study, we learn that compared to standard post-heart attack medical therapies, the benefits of fish oil were not significant:
“after adjusting for standard post-MI (heart attack) medical therapies, there was only a nonstatistically significant trend for the treatment effect of O-3FA (omega-3 fatty acids) on noninfarct myocardial fibrosis (abnormal scarring of the heart muscle).”
Harms should have been included.
As made clear in a New York Times story, Dr. James Stein of the preventive cardiology department at the University of Wisconsin Hospital and Clinics explained that “fish oil can be hazardous when combined with aspirin or other blood thinners.” This seems particularly pertinent here as post heart-attack patients are often recommended to take aspirin.
The article provides an accurate description of the study design, including the sample size and type of design.
There is, however, a lack of discussion around study limitations. And the limitations were significant enough that we feel they should have been included in any news coverage. For example, readers should be strongly reminded that the study was measuring surrogate markers, and not direct events like repeat heart attacks.
And importantly, the study notes that “a substantial proportion of patients could not return for the post-treatment follow-up visit” and that “no specific recommendations were given with regard to dietary omega-3 fatty acid intake.”
There is no disease-mongering.
Only the lead investigator, Dr. Raymond Kwong, was interviewed.
No alternatives to fish oil were discussed.
Most people understand that fish oil is available over the counter, so we’ll rate this Satisfactory–though just marginally, because the fish oil prescribed to people in the treatment arm of the study was not standard over-the-counter fish oil pills; see our discussion on this in the “Discuss costs” section above.
The article demonstrates a good understanding that the novelty of the study lies in examining the protective benefits of fish oil right after a heart attack. That is, the study is novel in its patient population.
A further discussion of using MRI to assess heart conditions would’ve further highlighted the novelty of the study.
The article does not appear to be based on a news release.