Results from a highly anticipated study of fish oil and vitamin D generated conflicting headings last weekend. Some stories explained…
Results from a highly anticipated study of fish oil and vitamin D generated conflicting headings last weekend.
Some stories explained good news about the popular dietary supplements.
Reuters wrote that fish oil “can dramatically reduce the odds of a heart attack, while the benefits of vitamin D appear to reduce the risk of death from cancer.”
Washington Post reported that fish oil medications were “effective” to protect against cardiac events while Vitamin D was linked to a reduction in cancer death.
HealthDay said fish oil “could lower your heart attack”.
But others reported the opposite: Fish oil and vitamin D actually do not protect against the larger
CNN said they “do not prevent cancer or heart disease.” Associated Press reported “no clear ability to lower cardiovascular or cancer risks.” Kaiser Health News called them “no guard against serious cardiac problems.”
The New York Times denounced them “ineffective.” NPR said they “Mostly Disappoint.”
On Twitter, cardiologist Eric Topol pointed at the “little” contrast
The stories included the entire test Vitamin D and Omega-3 Trial (VITAL), which recorded 25,871 healthy people 50 and older and randomized them to prescription omega- 3 fish oil capsules, vitamin D supplements, both or just placebo. They were followed for an average of 5.3 years.
Two papers were published, one with results for fish oil, the other with results for vitamin D.
Here is the conclusion of fish oil study:
“Supplements with n-3 fatty acids did not result in a lower incidence of major cardiovascular events or cancer than placebo. “
Here is the conclusion of the vitamin D study:
” Vitamin D supplementation did not result in a lower incidence of invasive cancer or cardiovascular events than placebo.
Statements seem clear: no benefit
So why did some news organizations report differently?
The answer may be a press release issued by Brigham and Women’s Hospital, where the trial was conducted.
The issue focused on a handful of secondary findings that are not the top questions the researchers thought to answer.
For example, researchers observed 28% of the fall in heart rate among people taking fish oil. It increased to 40% in people who took fish oil but eating a little fish. The perceived effect was greatest among African Americans, who saw a 77% decrease.
Heart attack was just one component of a composite “cardiovascular event” measure as a lso included stroke and death from cardiovascular disease causes. Researchers often combine results in a composite score to make it easier to show a statistically significant disagreement between a treatment group and controls, which facilitates faster attempts with fewer patients. See also our primer on composite results.
Similarly, researchers also discovered fewer cancer deaths in people who took vitamin D for at least two years.
As we have written, such secondary findings must be reported carefully. They do not have the same statistical authority as primary findings, and are more likely to be chances. It has been pointed out that secondary findings should only be used to interpret the primary result of an attempt or to suggest ways for further research.
But the news phrase contained the roaring sound studies at the beginning, with formulations that made them sound like proven advantages: The subheading says omega-3 “reduced heart attacks” and that vitamin D “reduced cancer death” – similar to misleading cause language that showed say in some news.
Earle Holland, one of our contributors and a senior senior scientific and medical communications officer at Ohio State University, must be “extra cautious” to report the limitations of secondary findings because ” readers often assume causal relationships where there is no someone”.
“Building false hopes is basically cruel,” he said.
The news release played down the primary findings, describing them on the third page, and not flagging them as the main result.
“You can talk about the secondary endpoints if you want, but not to the point where you hide the overall study was negative,” said cardiologist Christopher Labos, MD, one of our reviewers who quoted a “link” between the press release and the study.
Matt Shipman, a public information officer at North Carolina State University and a HealthNewsReview.org contributor said, “It feels like publishing burys something.”
Obviously, the study’s main findings were buried so deeply that some journalists missed it.
We asked Brigham and Women, who received about $ 40 million from the National Institute of Health to drive the trial, why their press release featured the main results, elevated secondary findings and did not explain different levels of evidence.
The hospital responded with a statement defending how data was presented. It is said that all information in the release is correct and “supported by the results”.
Leadership Researcher JoAnn Manson, MD, Hospital Director of Preventive Medicine, noted that the secondary endpoints had been planned before the trial was conducted and was
“We do not think that information should be kept from the public,” says Manson in an email.
Note that no one has said anything about containing the secondary results. We are talking about providing adequate explanations and contexts.
Some news organizations leading the primary score also reported the secondary findings, but wisely included caveats.
For example, Kaiser explained how to analyze data in smaller pieces for analysis can give unreliable results and “links between fish oil and heart attacks – and vitamin D and cancer deaths – may be due to chance.”
In addition to appearing to be dependent on the press release, these news did not include much input from independent sources. HealthDay used one who hyped the secondary conclusion of myocardial infarction as “deep”. Reuters and the Post had no.
Posten and HealthDay confused further things in the way they covered another attempt called REDUCE-IT in the same story. REDUCE-IT showed an advantage for a specific population of people with heart disease who took a medicine with oil of oil called Vascepa (icosapent ethyl).
Both VITAL and REDUCE-IT involve fish oil, presented the same day at an American Heart Association meeting, conducted at Brigham and Women’s, and was published simultaneously in the New England Journal of Medicine.
We have often noted that negative or zero results have difficulty attracting news coverage.
Vital’s hard coverage shows that it may be different. Its results challenge common beliefs, which is the essence of a good news story.
Brigham and Women, however, welcomed the taxpayers’ insights with doubtful positive results and some news organizations were continuing.
“This may be a function of bias in academic research against negative results, which is unfortunate,” said Shipman. “Negative results can have enormous value. In my opinion, the negative results are the bigger story in this case.”
Martha Gulati, MD, Head of Cardiology at the University of Arizona, agreed on the results “did not have to be spinning” and helps people make more informed choices.
“As a health consumer myself, I do not want to spend my income on something that does not give any benefit,” she said.