Dietary salt intake and cardiovascular outcomes: an umbrella review of meta-analyses and dose-response evidence.

Fanjing Kong, Qian Liu, Qing Zhou, Pengyang Xiao, Yiling Bai, Tianyu Wu, Lina Xia

Journal: Annals of medicine 2025;57(1):2582065

PMID: 41243115

Plain Language Summary

Cardiovascular disease, which includes heart attacks and strokes, is one of the leading causes of death worldwide. High blood pressure is a major risk factor for these conditions, and dietary salt (sodium) intake plays an important role in regulating blood pressure. However, there has been ongoing debate about how much salt people should consume and whether very low sodium intake might also carry risks. The aim of this umbrella review of 21 meta-analyses was to assess the overall strength, consistency, and dose–response relationship between sodium intake and cardiovascular outcomes.

The review found strong evidence that higher salt intake is associated with increased blood pressure and a higher risk of cardiovascular disease and stroke. Lower sodium intake was generally associated with reduced cardiovascular mortality and improved blood vessel function. It was also shown that as sodium intake increases, cardiovascular risk also increases. However, the authors noted variability between studies and highlighted that extremely low sodium intake remains an area of scientific discussion.

In conclusion, the overall evidence supports reducing excessive salt intake to lower blood pressure and reduce cardiovascular risk. Healthcare professionals can use this information to reinforce public health guidance aimed at limiting dietary sodium, particularly in individuals with high blood pressure or elevated cardiovascular risk. The findings strengthen existing recommendations to reduce high salt consumption as part of a heart-healthy dietary pattern.

Abstract

BACKGROUND

Excessive salt intake is a known cardiovascular disease (CVD) risk factor, but the health impacts of both high and low sodium intake remain debated. This study synthesize meta-analytic evidence on dietary salt intake and cardiovascular outcomes, including subgroup and dose-response analyses.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library were searched through August 28, 2024, for meta-analyses of randomized controlled trials and observational studies.

RESULTS

21 meta-analyses comprising 91 outcomes were included. Low sodium intake was associated with reduced risks of CVD mortality (RR = 0.83, 95% CI: 0.73-0.95), stroke mortality (RR = 0.74, 95% CI: 0.57-0.95), and all-cause mortality (RR = 0.88, 95% CI: 0.82-0.93), as well as systolic blood pressure (MD = -3.39 mmHg) and diastolic blood pressure (MD = -1.54 mmHg), improved vascular elasticity, and increased heart rate. Urinary sodium excretion and Na/K ratio decreased, while urinary potassium, calcium, and serum potassium increased. No adverse effects on lipid profiles were observed. High salt intake was associated with increased risks of CVD (RR = 1.13, 95% CI: 1.06-1.20), hypertension (OR = 1.33, 95% CI: 1.24-1.42), stroke (OR = 1.34, 95% CI: 1.19-1.51), and stroke mortality (OR = 1.40, 95% CI: 1.21-1.63). Each 1 g/day sodium increase raised systolic blood pressure by 0.60 mmHg and CVD and stroke risks by 4% and 6%, respectively.

CONCLUSION

High salt intake increases cardiovascular risk, while moderate reduction provides protective benefits without adverse lipid effects. Tailored strategies are needed based on regional, sex-specific, and methodological differences.

Address: School of Health Preservation and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China.; School of Acupuncture-Moxibustion and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China.

DOI: 10.1080/07853890.2025.2582065