9,125 cups of coffee a year still good for you?

By | July 15, 2019

Posted By


Gary Schwitzer is the founder and publisher of HealthNewsReview.org.  He tweets as @garyschwitzer, or as @HealthNewsRevu.

As crazy as our headline sounds, it is merely taking CNN’s headline, below, and spreading it out over a year.

CNN quoted one of the researchers:

The main message for people to take away from this is that coffee can be enjoyed as part of a healthy lifestyle, and coffee lovers can be reassured by this result in terms of blood vessel stiffness outcomes. (emphasis added)

Note that they didn’t report fewer heart attacks or fewer cases of heart disease.  “In terms of blood vessel stiffness” was the endpoint.  A surrogate endpoint, which, as our helpful primer points out, often doesn’t tell the whole story.

Seeking independent perspectives to analyze studies helps get at the bigger picture.

The Huffington Post reported:

“This is rather silly and irresponsible reporting in my view,” Dr. David Katz, a director at the Yale-Griffin Prevention Research center, told HuffPost. …

“This study does not prove that 25 cups of coffee a day are reliably safe,” Katz said. “It simply shows lack of one very specific harm in a population where some few self-selected to drink that much, quite possibly suggesting an extreme tolerance the rest of us do not enjoy.”

Fox News was among those reporting a quote from an official of the British Heart Foundation (which helped fund the study), claiming that the study “will hopefully put some of the media reports in perspective, as it rules out one of the potential detrimental effects of coffee on our arteries.” Earlier in the Fox story, one of the researchers admitted, “We can’t prove a causal link in this study.”  So, you see, it didn’t rule out anything because it didn’t prove anything – except that the coffee craziness continues.

Read More:  A Staggering Number of Athletes Collapsed This Past Year


Meantime, blood vessel stiffness was also at the center of hyperbolic heart health claims at the New York Times this week. Another all-too-brief Times story of 200 words and some change.

At the end, the story acknowledged that “The study received support from the U.S. Highbush Blueberry Council.” But it still allowed the lead researcher, whose work was supported by this blueberry industry money, to project the benefits that would come “If everyone ate more fruits and berries…”  There was no independent expert perspective in the story, only that promotional quote from a conflicted researcher.

But let’s take a closer look at the evidence. The story reported:

The authors estimate that eating a cup of blueberries a day reduced the risk of any cardiovascular event by 13 percent and the risk of coronary heart disease by 11.4 to 14.5 percent.

Really?  How did they estimate reduced risk of cardiovascular events or coronary heart disease? The story continues:

But compared with the half-cup consumers and the placebo group, the full-cup group had reduced arterial stiffness (emphasis added) and increased levels of HDL (the “good” cholesterol). Those eating lots of blueberries also had increased levels of anthocyanin, a type of antioxidant found in plant pigments, and increased levels of cyclic guanosine monophosphate, a substance that relaxes smooth muscle cells and improves blood flow.

There’s that arterial stiffness again, along with other surrogate endpoints such as levels of HDL, anthocyanin and cyclic guanosine monophosphate. Should we really devote “all the news that’s fit to print” attention to these surrogates, suggesting that readers become fixated on more and deeper concerns about what silent killers may be lurking inside them?  Or should we educate them about the outcomes that really matter when they hear about research? These surrogates are legitimate research pursuits, but news stories that elevate them to the level of heightened consumer concern – without explaining the limitations of such surrogates – are useless.

Read More:  Casting Believable Characters for Your Story or Screenplay

Can’t you just imagine the subway conversations as people read the Times?  “Yo, how’s your arterial stiffness today?”

As we’ve noted before regarding unhelpful briefs from the Times, smart reader comments demonstrate that this kind of news is turning off a lot of people.  Some examples of comments left by readers on the Times website:

  • But what else were the study participants eating? Judging from the fact that they were overweight or obese, and at high risk for cardiovascular disease, I would guess it’s a Standard American Diet (SAD), high in processed and ultraprocessed foods, as well as animal products (meat, dairy, eggs).
  • So the people who grow and sell blueberries paid for a study that concluded blueberries are good for us. Yeah, Yeah.
  • Perhaps daily stories like this produce more harm than good when recommending impossible to sustain daily eating habits.

You might also like