Thursday, August 04, 2011

Journalism, salt and ethics.

First, some background.

In early July, the well respected Cochrane Review folks put out a piece on dietary salt reduction and cardiovascular disease. Their review basically had three non-overlapping and somewhat contradictory conclusions. The first (gleaned from their plain language summary) was,

"Cutting down on the amount of salt has no clear benefits in terms of likelihood of dying or experiencing cardiovascular disease"
The second was,
"Our findings are consistent with the belief that salt reduction is beneficial in normotensive and hypertensive people"
While the third was,
"The challenge for clinical and public health practice is to find more effective interventions for reducing salt intake that are both practicable and inexpensive"
The media pretty much only reported on that first bit, with headlines screaming, "It's Time to End the War on Salt", "Review says salt not responsible for heart attacks", "Study Denies Any Link between Sodium Intake and Heart Risk", and "Now salt is safe to eat — Health fascists proved wrong after lecturing us all for years".

I blogged about how it seemed to me, many of the journalists who wrote about the Cochrane Review, must not have bothered reading it, given the message it contained, truly wasn't the message they conveyed. Of course I'm just some doc with a blog, and admittedly, I'm not a statistician, nor am I a hypertension researcher, maybe I misread something?

Well, Drs. Feng J. He and Graham A MacGregor are hypertension researchers (and certainly their likely confirmation bias' are that salt's bad), and they decided to pen a commentary on the Cochrane Review that was published this past week in the Lancet.

Summarizing their commentary - if you exclude the one paper in the Cochrane Review's analysis that was poorly designed (the one on patients with heart failure whose diuretic medications weren't adjusted when patients were placed on low-salt diets (a bad plan) which had negative outcomes for salt reduction), the remaining 6 papers, when combined to increase power, demonstrated a statistically significant reduction in cardiovascular events with salt reduction, and a non-statistically significant reduction in all cause mortality.

It's a very compelling little commentary, as confirmation bias or not, their arguments seem quite rational, and while it received some play in the press, it didn't receive near the same play as what seems to be the preferred new controversial narrative, that salt's no longer a worrisome thing.

So that leads me to my question, one I've posed before, is the ultimate responsibility of the journalist to the public, or to the press?

My idealism has me on the side of the public, but my cynicism (realism?) has me on the side of the press, knowing full well that telling the public what they want to hear will trump evidence more often than not.

Too bad too, think of the immense public health benefits of a unified press corps that preferentially reported science over hype, truth over contrarianism, and thoughtful discussion over grabby headlines.