May 14, 2013

salt

The NY Times has a piece up on salt intake. Specifically it is about a report done by the Institute of Medicine of the National Academies titled, "Sodium Intake in Populations: Assessment of Evidence.".

I have read the entire report.

The purpose of the report is to determine if health advisories suggesting people consume less than 2,300 mg of salt or even as low as 1,500 mg of salt, especially those over 51 does anything. Currently the average US person consumes 3,400 mg of salt.

The report was pushed forward by the CDC and it recommended the Institute convene an expert committee to run it. The committee looks legit. Health professionals as well as statistical experts. There were no funny food companies behind the research.

It was kind of a meta-analysis of other studies but technically not a meta-analysis.

For outcomes related to CVD, stroke and mortality the studies were ALL observational. Translated? They were worthless.

For outcomes related to heart failure there were some randomized clinical trials (RCTs). Translated? These are all that matter.

So what did they find?

First and most interesting was they basically deemed the entire set of salt research to be crap. Poorly done, poorly designed, and ultimately worthless.  I love that. In particular they cited the use of observational studies as useless and the measurement of salt intake to be pathetic (e.g., people reported how much salt they ate.). They caveated the whole report. To such an extent that the conclusions almost read like they had to force them because they couldn't put out a report that said, "We don't know anything." And frankly as a result of that we should stop reading there. But let's see what they say.

Basically they say that yes salt is correlated with CVD risk but that the 2,300 mg per day recommendation has no basis. And in fact the effect of salt on CVD risk (as in how much does the risk go up) was completely unquantifiable. I read that to mean it is minimal at best. They went on to say that there was evidence however from RCTs that low salt intake (defined as 1,840 mg per day) can lead to an INCREASED risk of adverse effects for people who have heart problems. And that this probably extends to people who don't have heart problems.

No comments: