Salt substitutes, unlike regular salt, contain reduced amounts of sodium chloride (table salt) and have potassium chloride as a supplement. Table (regular) salt is 100% sodium chloride: salt substitutes contain 75% sodium chloride and 25% potassium chloride.
Several studies have linked high salt intake to increased risks of hypertension, stroke, chronic kidney disease, and myocardial infarction. Studies have shown that salt substitutes are associated with lower risks of stroke and other modifiable cardiovascular events like heart attacks (myocardial infarction). However, most of the studies used observational data and followed participants for a short duration.
In a new study, Bruce Neal et al. evaluated the effect of salt substitution on cardiovascular events and death, with fascinating results. In an open-label, cluster-randomised trial with an intention-to-treat, Bruce Neal and colleagues recruited 20,995 persons from 600 villages in rural China between 2014 and 2015. They then divided them into two groups in a 1:1 ratio. In one group, participants were to use prespecified salt substitutes. In the other group, participants were to use table (regular) salt. They then followed them up for five years with a primary outcome of stroke. The secondary effects were major cardiovascular events and death from any cause. They also monitored the participants for symptomatic elevated potassium levels.
Another interesting article!
By the end of the study, the salt substitute group had lower rates of stroke, major cardiovascular events and death compared to the regular salt group. Both groups registered adverse events due to elevated potassium levels (hyperkalaemia), but they were no significant differences. It was evident that salt substitution reduces the risk of stroke, major cardiovascular events like myocardial infarction, and death.
Theoretically, Reduced salt intake leads to reduced water retention within the blood vasculature. It culminates in lower blood pressure which in turn reduces the risk of myocardial infarction and stroke. Reduced salt intake is protective to the heart, as well as the kidneys. Potassium supplements potentiate this protective effect.
Much as several studies had delineated the protective effects of salt substitutes, none of them had gathered data about their safety profile until Bruce Neal et al. pulled off practice-changing research. We applaud them for such a feat.
Their trial data and results are available in the New England Journal of Medicine. You can read or download the paper from here. Enjoy the reading.