REDUCTION IN BLOOD-PRESSURE WITH A LOW-SODIUM, HIGH POTASSIUM, HIGH MAGNESIUM SALT IN OLDER SUBJECTS WITH MILD-TO-MODERATE HYPERTENSION

Objective-To examine the effect of a reduced sodium and increased potassium and magnesium intake on blood pressure. Design-Randomised double blind placebo controlled trial. Setting-General population of a suburb of Rotterdam. Subjects-100 men and women between 55 and 75 years of age with untreated mild to moderate hypertension. Interventions-During 24 weeks the intervention group received a mineral salt (sodium: potassium: magnesium 8:6:1) and foods prepared with the mineral salt. Controls received common salt and foods. Main outcome measure-Change in blood pressure. Results-Complete follow up was achieved for 97 of the 100 randomised subjects. Systolic blood pressure (mean of measurements at weeks 8, 16, and 24) fell by 7.6 mm Hg (95% confidence interval 4.0 to 11.2) and diastolic blood pressure by 3.3 mm Hg (0.8 to 5.8) in the mineral salt group compared with the controls, with a 28% decrease in urinary sodium excretion and a 22% increase in urinary potassium excretion. Twenty five weeks after the study the difference in blood pressure between the groups was no longer detectable. Conclusion-Replacing common sodium salt by a low sodium, high potassium, high magnesium mineral salt could offer a valuable non-pharmacological approach to lowering blood pressure in older people with mild to moderate hypertension.