Cutting Salt “Works as Well” as Blood Pressure Medicines?
Please. We don’t need fake controversies and false comparative claims. But in reporting on an excellent new study of the effects of cutting salt on blood pressure, we’re getting a little bit of both. The study that is generating this frenzy simply doesn’t line up with the headlines that reporters are spinning out of it.
Researchers published a report this weekend in JAMA and presented it at the American Heart Association Scientific Sessions, comparing the effect of a low-sodium diet to a high-sodium diet. But headline writers wanted to make a comparison to blood pressure medicines. “Cutting one teaspoon of salt works as well as blood pressure meds,” they wrote.
The only trouble is that this study was in no way a study of the effects of blood pressure medicines. So the comparison is bogus. An overreach.
A Carefully Designed Crossover Study
The study itself is excellent. A total of 213 individuals with diverse clinical presentations regarding blood pressure enrolled. Some had normal blood pressure or controlled hypertension. Others had uncontrolled or untreated hypertension. They randomly received either a high-sodium or low-sodium diet for a week and at the end of that week, crossed over to a week of the other diet.
The results provide us clear evidence that a cutting salt reduced blood pressure in roughly three quarters of this patient population. Not everyone, but most people benefitted. The authors noted that the magnitude of change is similar to the benefit seen with a diuretic commonly prescribed for high blood pressure. But that was not their primary conclusion and this was not a study comparing sodium reduction to medicines for hypertension. The real conclusion is this:
“Dietary sodium reduction significantly lowered blood pressure in the majority of middle-aged to elderly adults. The decline in blood pressure from a high- to low-sodium diet was independent of hypertension status and antihypertensive medication use, was generally consistent across subgroups, and did not result in excess adverse events.”
Puffery and Salty Controversies
It does seem that cutting back on sodium in the food supply, as FDA is aiming to do, is a reasonable approach to improving cardiovascular health across the population by nudging the prevalence of hypertension a little lower. There’s no need for hyperbolic comparisons of sodium reduction to hypertension meds. Each of these approaches has its place.
Dogmatic advocates for sodium reduction suggest that people who disagree with their ideas “support food and beverage industry’s vested interests in the use of excessive amounts of salt to preserve food, enhance taste, and increase thirst.”
But there is room for a diversity of views. Indeed, not everyone will benefit from sodium reduction. Some will see an increase in their blood pressure, which the authors of this new study note in their own data and acknowledge as an issue to consider.
Issues of public health deserve public discourse that is full, fair, and truthful.
Click here for the study from JAMA, then here, here, and here for perspective on the issues that arise in conversations about dietary sodium.
Salt Meadow in October, painting by John Frederick Kensett / WikiArt
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November 14, 2023
