The parade of stories about coffee preventing this or that disease continues. We wish there was more skepticism applied to these kinds of studies. And we wish such stories would remind readers that correlation does not equal causation.
The inclusion of some cautious expert comments at the end helped atone for some of the excesses higher up in this piece, but the overall message was still hazy at best. The story gives the same weight to recommendations from one of the study researchers, who advises drinking 3 cups of coffee a day to prevent Alzheimer’s, as it does to the independent expert, who says we can’t recommend coffee for Alzheimer’s prevention until we test it in a clinical trial. Whom should we believe?
Readers of this story who are concerned about mild memory loss in themselves or loved ones will likely come away with an imperative to consume more caffeine. They would have been better served with a balanced piece including limitations of this study and observational research in general.
People don’t have the time, money, or motivation to follow every recommendation they hear about that might benefit their health. Journalists should help guide readers toward solid advice based on quality evidence. If journalists don’t raise the serious questions about efficacy or harm, how will people learn to filter stories such as this?
The cost of coffee is not in question.
The story just had too many unsupported statements about the benefits of coffee to earn a satisfactory here. Examples:
Caffeine can cause anxiety, poor sleep, irritative bladder symptoms, palpitations, and even arrythmia. Older people are at greater risk for each of these problems and should be aware of the adverse effects of caffeine, even at lower levels of intake.
This was a case-control study, a design which sits near the bottom of the hierarchy of medical evidence because it is prone to bias. However, apart from the mild cautionary comments offered by the independent expert at the end of the story (“the jury is still out on how or if caffeine affects risk for Alzheimer’s”), there was no critical analysis of the study or possible limitations of the data. The story also repeatedly used cause-and-effect language (“Drinking Coffee May Delay Alzheimer’s Disease”) to describe the benefits of coffee for prevention of Alzheimer’s and other diseases, when the available evidence doesn’t support these assertions.
No disease-mongering of Alzheimer’s disease.
An independent expert injects some important cautionary notes, We wish this perspective had been featured more prominently, and that more experts had been consulted.
There aren’t any proven strategies to reduce Alzheimer’s risk. However, there are a number of lifestyle factors — exercise, healthy diet, etc.– that have at least as much evidence to support them as coffee. The story could have mentioned these.
The availability of coffee is not in question.
The independent expert notes that there are other studies supporting a possible beneficial effect of coffee on Alzheimer’s disease.
The story did not rely excessively on this press release put out by the University of South Florida.