Maybe Salt Isn’t So Bad For You?

Aren’t you getting rather tired of the ‘good news, bad news’ see-saw when it comes to what we like to eat and drink?  Coffee causes cancer, but prevents diabetes; alcohol helps your heart and brain, but damages your liver; fish is brain-food, but you risk mercury poisoning; and so on.  Here’s a new one.  After salt has been demonized for the last decade (or even longer), a new Cochrane Review brings some better news for salt-lovers.  The anticipated cardiovascular benefits of salt restriction remain unproven, based on currently available evidence.  

The authors selected randomized controlled trials with follow-up of at least 6 months that compared dietary salt reduction to no such intervention.  The 7 trials chosen had some 6,300 adult participants.  They included subjects with normal blood pressure (3,500), high blood pressure (750), a mixed population (2,000), and 232 patients with heart failure.  The longest follow-up was 12½ years.

Salt reduction was associated with an average decrease in systolic blood pressure between 1 and 4 mm Hg.  Mortality rates and cardiovascular events were reduced, but not statistically significantly, i.e. these effects might have occurred by chance alone.   And among the heart failure patients there was an increased risk for all-cause mortality after salt restriction.

The authors conclude that the antihypertensive effects of salt restriction in both normal and hypertensive subjects are present, but they are small and insufficient to produce significant clinical benefits in the populations measured in these trials.  Obviously, ‘more studies are needed’, as we always say.  Meanwhile, it’s probably a little safer to use the salt cellar than we thought - even if you have heart failure.  But make sure your high blood pressure is under control.