Salt substitution associated with lower mortality
A systematic review and meta-analysis found that salt substitutes may be associated with lower risk for all-cause and cardiovascular mortality but noted that most of the evidence is from older populations and those eating an Asian diet.
Salt substitution in food preparation was associated with a lower risk for both all-cause and cardiovascular mortality, according to a recent study.
Researchers conducted a systematic review and meta-analysis of 16 randomized controlled trials (RCTs) of people using regular table salt or salt substitutions for at least six months. The results were published April 9 by Annals of Internal Medicine.
According to the findings, salt substitution may reduce risk for all-cause mortality (six RCTs; 27,710 participants; rate ratio [RR], 0.88 [95% CI, 0.82 to 0.93]; low-certainty evidence) and cardiovascular mortality (four RCTs; 25,050 participants; RR, 0.83 [95% CI, 0.73 to 0.95]; low-certainty evidence). In addition, salt substitutes may result in a slight reduction in major adverse cardiac events (three RCTs; 23,215 participants; RR, 0.85 [95% CI, 0.71 to 1.00]; very low-certainty evidence). However, the evidence of the effect of salt substitution on serious adverse events is very uncertain (six RCTs; 27,995 participants; risk ratio, 1.04 [95% CI, 0.87 to 1.25]).
The authors concluded that salt substitution may reduce all-cause or cardiovascular mortality but that the evidence that it reduces cardiovascular events and doesn't increase serious adverse events is uncertain.
Eight of the 16 included RCTs studied primary outcomes, but seven of these were from China or Taiwan, where salt intake is high, the authors noted. In addition, they said, most of the evidence came from one large trial, and seven of the 16 studies included older persons, who are at higher risk for cardiovascular disease. Because of these factors, generalizability to populations with average cardiovascular disease risk or following a Western diet is limited.
"Although progress to reduce sodium intake has been achieved in several Western countries, this has primarily been through system-level policies to lower sodium targets in processed foods," the study authors wrote. "However, sodium intake is still high, and there is still room for improvement. Salt substitution may be a simple approach to help achieve reductions in salt intake, particularly where most salt is added during cooking at home."
An accompanying editorial noted that one-third of countries worldwide continue to adopt only voluntary measures of sodium reduction. Only 22% of countries have adopted at least one mandatory measure, and only 5% implement the World Health Organization's guidance. No country is on track to achieve the World Health Organization's global target of 30% reduction in sodium intake by 2025, the editorial said. The authors suggested that the widespread use of salt substitutions provides an achievable, accessible means to reaching that goal for the global food production industry.
"Given the high rates of nonadherence to antihypertensive medication, nonpharmacologic measures at the population level to improve blood pressure control are required," the editorial stated. "Expanding the routine use of potassium-enriched salts across households and the food industry would benefit not only persons with existing hypertension but all members of the household and communities. An entire shift of the population's blood pressure curve is possible."