Salt substitute reduces risk of heart attack, stroke, and death

Cardiovascular disease is the leading cause of death worldwide and hypertension is a major risk factor for premature death. A lack of dietary potassium and an excess of dietary sodium are common causes of hypertension.

study: Effects of salt substitutes on clinical outcomes: a systematic review and meta-analysis. Image credit: Andrey_Popov / Shutterstock.com

Background

Several previous randomized trials have reported that potassium supplementation and reduced sodium intake can lower blood pressure. is found in reduced-salt and potassium-enriched salt substitutes in which potassium chloride (KCl) replaces

Recently, the Salt Substitute and Stroke Study (SSaSS), a 5-year cluster-randomised trial in 600 villages in China, provided evidence that salt substitutes can protect against death, cardiovascular events, and stroke. provided. The SSaSS also addressed concerns about the adverse effects of dietary potassium supplementation and the risk of hyperkalemia. The improved clinical outcome observed with SSaSS is primarily mediated by a reduction in blood pressure.

new heart A journal study provides a systematic review of the effects of salt substitutes on clinical outcomes and blood pressure for all available trials. Researchers also sought to determine the consistency of findings across different regions and populations.

About research

In this study, we searched Embase, Cochrane, and MEDLINE databases for keywords such as low-sodium salt, alternative salt, potassium salt, and low-salt salt through August 31, 2021.

All studies in which clusters or adults were randomly assigned to regular or alternative salts were included. Mortality, blood pressure, cardiovascular events, and cardiovascular mortality were the most common outcomes.

Study titles and abstracts were screened by a single author to assess eligibility, whereas full-text versions were independently reviewed by the authors. Differences between reviewers were resolved through referencing with third-party authors.

Participant and study characteristics, and all results were extracted from the records. Risk of bias for all studies was also determined independently.

Survey results

The current analysis included 3 cluster randomized trials, 17 individual randomized trials and 1 stepwedge randomized trial. Of the included studies, 11 were conducted in the World Health Organization (WHO) Western Pacific Region, 5 in the WHO European Region, 1 in the WHO Southeast Asia Region, and 4 in the WHO Americas Region.

Intervention duration ranged from 1 to 60 months. The proportion of NaCl in the salt substitutes varied from 33% to 75% and the proportion of KCl varied from 25% to 65%.

Mean baseline systolic blood pressure (SBP) was between 113 mm Hg and 177 mm Hg, and mean baseline diastolic blood pressure (DBP) was within the range of 71 mm Hg to 105 mm Hg.

Baseline mean 24-h urinary sodium excretion ranged from 2.9 g to 5.5 g, and daily mean 24-h urinary potassium excretion ranged from 0.8 g to 3.6 g. Overall risk of bias was high in two studies, of some concern in eight studies, and low in 11 studies.

An overall −4.61 mm Hg decrease in SBP and a −1.61 mm Hg decrease in DBP was observed for salt substitutes compared to controls. A study duration of less than 12 months was associated with greater reductions in DBP and SBP.

We observed that DBP decreased significantly with lower percentages of NaCl in the salt substitute and higher potassium intake at baseline. Moreover, these results were found to be consistent across different geographic regions and populations.

In addition, five studies reported effects on mortality, two on major cardiovascular events, and three on cardiovascular mortality. However, six studies reported no serious adverse events related to hyperkalemia, while two studies reported no effect of salt replacement on serum potassium levels.

Salt substitutes also decreased urinary sodium excretion by -0.48 g/day and increased urinary potassium excretion by 0.45 g/day.The effects on potassium excretion were highest in the European region and lowest in the Southeast Asian region. Furthermore, the increase in urinary potassium secretion was higher in men.

Conclusion

The current study demonstrated that salt substitutes can provide consistent blood pressure-lowering effects across diverse populations and geographies without causing severe adverse events.

Salt substitutes can be employed in public health policy and clinical practice to reduce dietary sodium intake. Additionally, these substitutes increase dietary potassium intake, ultimately lowering blood pressure and preventing serious cardiovascular disease.

Limitations

Complete data were not available for many studies and no gray literature was searched. An additional limitation was the relatively small number of trials available.

Limited data on non-hypertensives make it difficult to draw definite conclusions. Finally, data on clinical outcomes are primarily from one of his trials.