Starting with the headline, this story is careful to explain that the study observed fewer strokes in those who ate more chocolate; it doesn’t suggest that the chocolate prevented strokes. It also features excellent use of statistics, a more explicit description of potential harms, and mentions alternative approaches to prevention. The only major shortcoming was a lack of an independent perspective on the findings.
Some journalists may balk at our insistence that stories about observational studies include appropriate discussion of the limitations of the evidence. In only 378 words, this story provides another example that this can be done – and it doesn’t require the length of a full medical journal article to do so.
We’ll rule this not applicable because, in general, most people have ballpark knowledge of how much chocolate costs. The story did not mention that dark chocolate is typically more expensive than milk chocolate — especially for the premium brands with very high concentrations of cocoa solids. A brief explanation would have been helpful.
The story went the extra mile here, providing the absolute rates of stroke seen in the groups consuming the lowest and highest quantities of chocolate. “Among those with the highest weekly chocolate intake — more than 45 grams — there were 2.5 strokes per 1,000 women per year. That figure was 7.8 per 1,000 among women who ate the least (less than 8.9 grams per week).” These statistics weren’t provided in the study text, suggesting that the writer made the calculations based on data contained in one of the study tables. We applaud the extra effort made to provide meaningful statistics to readers!
Close call here, but the story goes a step further than WebMD when discussing the possible adverse effects of consuming too much chocolate. In addition to warning that chocolate has a lot of fat, sugar and calories, it explicitly notes that eating too much of it “could be counterproductive.” WebMD offers no comparable warning and suggests that eating more chocolate than was consumed in this study would result in similar health benefits.
This story was much more cautious in its depiction of the findings than the competing WebMD coverage. Most important, it was careful to explain high up that the study found only a correlation between chocolate intake and lower stroke risk. As one of the study authors explains: “Given the observational design of the study, findings from this study cannot prove that it’s chocolate that lowers the risk of stroke.” We also appreciate the story’s more nuanced language regarding which constituents of chocolate might be responsible for possible benefits. Whereas WebMD states unequivocally that flavonoids and antioxidants “deserve the credit” for these benefits, Reuters says more judiciously that flavonoids “may be responsible for chocolate’s apparent effects on health.” [Emphasis ours.] “Whether that theoretical benefit translates into real-life benefits remains to be proven by rigorous studies, however,” Reuters appropriately adds.
There was no disease-mongering.
This was the only major shortcoming — no independent perspective. An expert in epidemiology might have pointed out, for example, that the data on chocolate consumption were collected from subject self-reports, and therefore should be viewed cautiously.
The availability of chocolate is not in question. The story appropriately notes that there is a stronger statistical association with dark chocolate as opposed to milk chocolate.
The story notes that previous research has linked higher levels of chocolate consumption with improved heart health.
The story includes comments attributed to a direct email from one of the study authors, so we can confirm our overall impression that this story wasn’t based on a press release.