Would someone tell the know-nothing busybodies over at the Center for Science in the Public Interest to please shut up about banning salt? The CSPI's anti-salt scare campaign claims:
Salt, at the levels present in the diets of most people around the world, is probably the single most harmful substance in the food supply. Salt is used liberally in many processed foods and restaurant meals, with some meals containing far more than a day's worth of sodium.
Reducing sodium consumption by half would save an estimated 150,000 lives per year. That in turn would reduce medical care and other costs by roughly $1.5 trillion over 20 years.
Not really. Yet another study—this time a review in the American Journal of Hypertension of seven randomized controlled trials by the respected Cochrane Collaboration—does not find consuming salt to be all that much of a health problem:
Relative risks (RRs) for all-cause mortality in normotensives (longest follow-up—RR: 0.90, 95% confidence interval (CI): 0.58–1.40, 79 deaths) and hypertensives (longest follow-up RR 0.96, 0.83–1.11, 565 deaths) showed no strong evidence of any effect of salt reduction CVD [cardiovascular disease] morbidity in people with normal BP (longest follow-up:RR 0.71, 0.42–1.20, 200 events) and raised BP at baseline (end of trial: RR 0.84, 0.57–1.23, 93 events) also showed no strong evidence of benefit. Salt restriction increased the risk of all-cause mortality in those with heart failure (end of trial RR 2.59, 1.04–6.44, 21 deaths). …
Our estimates of benefits from dietary salt restriction are consistent with the predicted small effects on clinical events attributable to the small BP reduction achieved.
Just take a look at the size of those confidence intervals. As MedPage Today described the results:
The seven studies included in the review consisted of three involving 3,518 normotensive participants; two involving 758 hypertensive participants; one with a mixed population of 1,981 participants; and one involving 232 patients with heart failure.
End-of-trial follow-up ranged from seven to 36 months and the longest period of observational follow-up was 12.7 years.
An analysis of normotensive participants showed that salt restriction was associated with a 33% reduction in the risk of death during the trial, declining to 10% at the end of observation. Both outcomes were associated with overlapping confidence intervals that precluded statistical significance.
The analysis of hypertensive participants showed even smaller effects of salt restriction on mortality: a 3% reduction at the end of the trial and 4% at end of observation.
Salt restriction was associated with a 29% lower risk of cardiovascular events among normotensive individuals and a 16% reduction in hypertensive participants. Neither difference achieved statistical significance.
In the trial involving patients with heart failure, salt restriction significantly increased the mortality risk more than twofold as compared with the control group (RR 2.59, 95% CI 1.04 to 6.44).
In May, my colleague Jacob Sullum, in a blogpost entitled "Could Eating Less Salt Be Deadly," cited new research showing the inconsequential health benefits of restricting salt consumption. Sullum makes the right point:
Whether or not eating less salt is dangerous, there is no reason to expect the entire population to adopt a diet that even its advocates concede they will not like if it benefits only a minority.
Food nanny motto: If some must suffer bland food, then all must suffer bland food!
Disclosure: At a check up last month, my blood pressure was 108/60.
Start your day with Reason. Get a daily brief of the most important stories and trends every weekday morning when you subscribe to Reason Roundup.