This story did a good job of explaining how researchers adjusted for different dietary and lifestyle variables among study participants.
However, many things are never discussed. There’s no mention of harms, costs, alternatives and study limitations. It does provide some minimal context on prior anthocyanin research.
The NPR story did a far better job explaining clearly: “It’s certainly not a perfect way to detect how certain foods may influence health, but it identifies important associations.”
This story’s quote – “Now a study published in the journal Circulation confirms and quantifies that benefit” – makes the research finding appear to be definitive. This is a troublingly misleading line.
The article emphasizes that a change in diet could affect heart-disease risk for relatively young women and lower a woman’s risk of having a heart attack later in life. However, that is not so clear, as Dr. Robert Eckel points out in the competing NPR story. More supporting evidence is needed before such statements can be made.
It is unfortunate that the role of berries described in this piece was not balanced by a brief discussion about the other preventive measures young women can take (e.g., (exercise, avoid overweight/obesity and don’t smoke), particularly with 1/3 of the population overweight or obese.
Not applicable. Cost of berries not discussed, but we can assume most readers know the ballpark costs.
The piece mentions that “women who ate three or more servings of blueberries and strawberries per week reduced their risk of heart attack by up to one third.” Again, this is the figure associated with anthocyanin, after adjustment of multiple variables. The limited understanding of anthocyanin and its levels in the body introduces an important limitation in the study. The protective effect may have been due to other factors, which is something the researchers acknowledge in their journal article.
Finally, the story did not make a clear statement about this study’s ability only to point to a statistical association – not to establish cause-and-effect – something we describe more in the “Evidence” criterion below.
Like both HealthDay and NPR, TIME also did not discuss potential harms. But all health interventions have harms, as well as benefits and costs.
We looked the other way and gave a N/A score for no discussion of costs, but we can’t do so with harms.
Like HealthDay, this story failed to identify any of the study’s limitations.
The biggest oversight was the failure to explain that an observational study like this – based on participants keeping a diary and self-reporting habits, has fundamental limitations. Moreso, such a study cannot establish cause-and-effect – only a statistical association. That’s still a valid piece of information – especially with such a strong statistical association in such a large sample. But it is inaccurate for a story about such a study to say that this “confirms and quantifies” the benefit. It can’t prove a benefit. Period.
Even though researchers tried to account for multiple factors in their analysis, it is impossible to account for all of them. They acknowledge in their study: “…it is impossible to disentangle the relative influence of all the constituents of fruits and vegetables.”
There is no disease mongering.
The story quotes one independent expert, preventive cardiologist Dr. Suzanne Steinbaum, who is the same doctor quoted in the HealthDay article. (Hmm, why is that?) We wish that she could have talked more on the limitations of the study, although her comment on benefits later in life more of an endorsement than a critical analysis: “…even if you are eating these early in life, you’re getting benefits that last for life.”
Nonethless, because an independent expert was quoted, we’ll give the story the benefit of the doubt.
Like the other two stories, no alternatives are mentioned. To prevent heart attacks, patients can either take medications, such as blood-thinning and cholesterol-lowering drugs, or make lifestyle changes, like maintaining a healthy weight, exercising and not smoking.
The availability of strawberries and blueberries is not in question.
The story does mention that previous studies have tried to analyze the effects of flavonoids, such as on arterial health. So it just barely makes the grade.
The Time story does not seem to rely solely on a press release, and there is evidence of original reporting with the independent comment from Dr. Suzanne Steinbaum.