A recent review, which debuted online in the Annals of Internal Medicine on April 9th, indicates a potential avenue for reducing the risk of all-cause or cardiovascular mortality through salt substitution. This implies that salt substitution could be a simple but promising strategy of improving cardiovascular health.

Salt substitution improves cardiovascular health outcomes

This comprehensive analysis, led by Hannah Greenwood and her team at Bond University in Queensland, Australia, delved into 16 randomized controlled trials to explore the enduring impact of salt substitution on cardiovascular health. Within this pool of trials, eight furnished data on primary outcomes, encompassing mortality, major cardiovascular events (MACE), and adverse events spanning six months or more.

Notably, seven of the analyzed trials targeted populations of older age or individuals with an elevated risk of cardiovascular issues. Within these demographics, the researchers unearthed promising evidence suggesting that salt substitution could potentially lower the likelihood of all-cause mortality and cardiovascular mortality. Specifically, the rate ratios for all-cause mortality and cardiovascular mortality were calculated at 0.88 (95 percent confidence interval: 0.82 to 0.93) and 0.83 (95 percent confidence interval: 0.73 to 0.95), respectively. Despite these encouraging findings, the certainty surrounding them was assessed to be relatively low.

Salt substitution leads to marginal decrease in MACE

Additionally, a marginal decrease in MACE was observed with salt substitution, with a rate ratio of 0.85 (95 percent confidence interval, 0.71 to 1.00), although the certainty of this evidence was very low. Moreover, there was very low-certainty evidence regarding serious adverse events, with a risk ratio of 1.04 (95 percent confidence interval, 0.87 to 1.25).

In conclusion, the authors assert that salt substitution presents itself as a promising intervention for lowering mortality rates, offering a low-cost and scalable alternative to pharmacological interventions. Despite the promising findings related to mortality outcomes, the evidence regarding the reduction of MACE is characterized by very low certainty, and there appears to be no increased risk of serious harms associated with salt substitution.