VERLAGING VAN DE BLOEDDRUK DOOR GEBRUIK VAN EEN MINERAALZOUT MET EEN VERLAAGD NATRIUMGEHALTE EN EEN VERHOOGD KALIUM- EN MAGNESIUMGEHALTE BIJ OUDEREN MET MILDE TOT MATIGE HYPERTENSIE

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, the Netherlands. Method. Of 100 men and women between 55 and 75 years of age with untreated mild to moderate hypertension, the intervention group received a mineral salt, consisting of 41% sodium chloride, 41% potassium chloride, 17% magnesium salts and 1% trace elements, and foods prepared with the mineral salt, during 24 weeks. Controls received common salt and foods. 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) decreased by 7.6 mmHg (95% confidence interval 4.0 to 11.2; p < 0.001) and diastolic blood pressure by 3.3 mmHg (0.8 to 5.8; p = 0.009) 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.