Better Health: Smart Health Commentary Better Health (TM): smart health commentary

Article Comments

Coffee And Prostate Cancer: The Quality Of News Reports Varies Significantly

We simply don’t know why more news organizations can’t do an adequate job of explaining the limitations of observational studies – most notably, that they can’t prove cause and effect.

Yes, they can show strong associations. But they can’t prove cause and effect.

NBC Nightly News, as one example recently, inadequately explained the latest suggestion that coffee consumption can lower the risk of prostate cancer. In the anchor lead, Brian Williams framed this as another case of flip-flopping science, lightheartedly talking about what they say about “all those medical studies…if you don’t like the findings, wait for the next study.”

The story seemed puzzled at how the same “lab” 30 years ago reported that coffee was linked to an increase in pancreatic cancer. NBC said the researchers later said they got it wrong. This time – with the prostate cancer link – they say they got it right.

There was not one word in the story about the limitations of observational studies – and that it’s not a black-and-white issue of “wrong” or “right.” In fact, it’s often a matter of how researchers and journalists communicate and translate the findings.

To worsen the problem, NBC’s science correspondent asked about the new finding, “If not caffeine, what is the cause?” But that implies that a causal link – or the absence of a causal link – was established in this study.

All in all, it was not a good job. It ended with unwarranted and unsupported advice:

“At the very least men can enjoy a daily cup or more of coffee.”

Meantime, a story on easily and clearly reported:

“As with other questionnaire-based studies of coffee consumption and disease, the results do not prove that coffee directly prevents aggressive prostate cancer. The study shows only an association, although it is a relatively strong one.”

Shiuan Chen, Ph.D., director of tumor cell biology at the City of Hope Cancer Center in Duarte, California, says the evidence isn’t compelling enough for doctors to recommend that middle-aged men up their coffee intake. “I don’t think it’s any reason for changing habits in the immediate moment,” he says.

That’s markedly different than what NBC reported.

HealthDay did a good job in explaining:

A definite cause-and-effect link is still far from proven, experts say, and just how coffee might help thwart prostate malignancy isn’t clear.

“It’s probably too early to tell someone that [he or she] should go out and start drinking coffee just because of this study.”

Any consumer or any journalist could learn from some of the tips we give in our primer on the difference between causation and association.

And, by the way, it is possible to do a better job on such studies even on TV. CBS’ Jennifer Ashton emphasized association – not causation – throughout this segment.

*This blog post was originally published at Gary Schwitzer's HealthNewsReview Blog*

You may also like these posts

    None Found

Read comments »

Comments are closed.

Return to article »

Latest Interviews

IDEA Labs: Medical Students Take The Lead In Healthcare Innovation

It’s no secret that doctors are disappointed with the way that the U.S. healthcare system is evolving. Most feel helpless about improving their work conditions or solving technical problems in patient care. Fortunately one young medical student was undeterred by the mountain of disappointment carried by his senior clinician mentors…

Read more »

How To Be A Successful Patient: Young Doctors Offer Some Advice

I am proud to be a part of the American Resident Project an initiative that promotes the writing of medical students residents and new physicians as they explore ideas for transforming American health care delivery. I recently had the opportunity to interview three of the writing fellows about how to…

Read more »

See all interviews »

Latest Cartoon

See all cartoons »

Latest Book Reviews

Book Review: Is Empathy Learned By Faking It Till It’s Real?

I m often asked to do book reviews on my blog and I rarely agree to them. This is because it takes me a long time to read a book and then if I don t enjoy it I figure the author would rather me remain silent than publish my…

Read more »

The Spirit Of The Place: Samuel Shem’s New Book May Depress You

When I was in medical school I read Samuel Shem s House Of God as a right of passage. At the time I found it to be a cynical yet eerily accurate portrayal of the underbelly of academic medicine. I gained comfort from its gallows humor and it made me…

Read more »

Eat To Save Your Life: Another Half-True Diet Book

I am hesitant to review diet books because they are so often a tangled mess of fact and fiction. Teasing out their truth from falsehood is about as exhausting as delousing a long-haired elementary school student. However after being approached by the authors’ PR agency with the promise of a…

Read more »

See all book reviews »

Commented - Most Popular Articles