The effects of a combined low-sodium, high-potassium, high-calcium diet on blood pressure in patients with mild hypertension

Nutritional sodium, potassium and calcium are considered to be: important regulators of blood pressure (BP). The present study evaluates the effects of combined low-sodium (LS), high-potassium (HK), high-calcium (HCa) diet on BP in patients with mild essential hypertension. Thirty-six patients (26 M, 10 F), 24-67 years of age(mean 46 +/- 8), participated in the study. Patients were divided into three groups and given a diet consisting of three 1-month segments, which they followed in different order. Group 1 (n = 11) received LS diet followed by the addition of HCa and then HK. The order in Group 2 (n = 12) was HK-LS-HCa; and in Group 3 (n = 13) it was HCa-HK-LS. The third month of the study all patients were eating a combined LS, HK and HCa diet. Urinary electrolytes were measured to confirm compliance with the diets. After 1 month of the LS diet urinary sodium excretion decreased significantly by 25 mmols/day (95% CI, 1-48 mmols/day); (P< 0.05). Eighteen patients did not comply with the diet. Systolic BP (SBP) only slightly decreased, from 142 mm Hg (95% CI, 137-146 mm Hg) to 138 mm Hg (95% CI, 133-142 mm Hg); (P = 0.11). The change in SBP was related to the change in urinary sodium excretion (R = 0.46; P = 0.006). After 1 month of the HK diet, urinary potassium excretion increased by only 5 mmols/day (P = NS). BP was unaffected by HK and HCa diet. At the end of the study, urinary sodium excretion decreased from 183 mmols/day (95% CI, 155-211 mmols/day) to 148 mmols/day (95% CI, 131-165 mmols/day); (P < 0.05), urinary potassium excretion slightly increased from 75 mmols/day (95% CI, 68-82 mmols/day) to 85 mmols/day (95% CT, 76-94 mmols/day); (P = 0.09), and urinary calcium excretion remained unchanged. BP did not decrease. It is concluded that only the LS diet may be advantageous in patients with mild essential hypertension.