The debate over salt and health continues to wallow at low levels of evidence: opinion or, at best, only observational outcomes studies (with one exception: a randomized trial showing that heart failure patients put on low salt diets suffered worse outcomes).
As a result, the Salt Institute, Grocery Manufacturers Association and many leading researchers are calling for a controlled trial of the health outcomes of the current policy of promoting salt reduction for everybody.
But while the salt controversy simmers, medical scientists are "moving on," recognizing that even well-designed randomized trials (RCTs) can produce results that can mislead policy decisions. TheHeart.org recently carried Sue Hughes' admonition to insist on "clinically significant" RCTs. Hughes summarizes an article in the February 2 issue of the Journal of the American College of Cardiology by Drs. Sanjay Kaul and George Diamond. That issue of JACC also contains an instructive article by Gregg W. Stone and Stuart J. Pocock on the same subject: the clinical significance of RCTs.
So, while salt reduction advocates want us to turn a blind eye to the conceded fact that six of the eight subgroups in the DASH-Sodium trial had no statistically-significant blood pressure improvement (and those subgroups would represent the overwhelming majority of the general public), the discussion in JACC is that statistical significance is not even enough: the findings also need to make a clinical difference. We read "clinical difference" to mean improved outcomes, not simply plausible theoretical modeling results.
Something public health nutrition policy-makers should consider.
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