In adults with high-normal BP or grade 1 hypertension, the DASH and Mediterranean diets with salt restriction similarly reduced 24-hour urinary sodium excretion (MD -9.1 mmol/24 h; P=0.72).
RCT (n=240)
randomly assigned
Does the DASH or Mediterranean diet combined with salt restriction improve 24-hour urine electrolyte indices in adults with high-normal blood pressure or grade 1 hypertension?
Both DASH and Mediterranean diets combined with salt restriction effectively improve sodium and potassium excretion, while the DASH diet is superior for increasing calcium and phosphorus excretion.
Mean Difference: -9.1
p-value: p=0.72
Objective: We aimed to assess the effects of a 3-month intensive dietary intervention implementing salt restriction, either alone or combined with the Dietary Approaches to Stop Hypertension (DASH) or the Mediterranean diet (MedDiet) on diet-related indices in 24-hour urine samples in adults with high-normal blood pressure (BP) or grade 1 hypertension. Design and method: We randomly assigned individuals to the control group (CG, n = 60), salt restriction group (SRG, n = 60), DASH diet with salt restriction group (DDG, n = 60), or MedDiet with salt restriction group (MDG, n = 60). All patients were followed monthly for 3 months. The goal for the patients in the three intervention groups was to restrict sodium intake to 2,000 mg/ day, either alone or combined with the assigned diet. The study outcomes included the attained between-group differences at 3 months post-intervention regarding sodium, potassium, calcium, and phosphorus levels in the 24-h urine samples, which were evaluated pre- and post-intervention to measure patients’ adherence to salt restriction and the assigned dietary patterns. Results: Of the 240 enrolled patients, 204 (85%) completed the study. According to the intention-to-treat analysis, compared to the CG, all three intervention groups had reduced mean sodium levels in the 24-hour urine samples at the 3-month evaluation (SRG vs. CG: mean difference = -41.1 mmol/ 24 h; DDG vs. CG: mean difference = -48.2 mmol/ 24 h, and MDG vs. CG: mean difference = -57.3 mmol/ 24 h, all P-values <0.001). The DDG and the MDG did not differ post-intervention concerning the amount of excreted sodium (MDG vs. DDG: mean difference = -9.1 mmol/ 24 h, P-value = 0.72). The DDG and the MDG had increased potassium levels in the 24-hour urine samples compared to both the CG and the SRG, whereas greater increases in the mean calcium and phosphorus levels were observed in the DDG compared to all other study groups. Conclusions: On a background of salt restriction, the DASH diet was superior in increasing calcium and phosphorus levels in the 24-hour urine samples, but the DASH and MedDiet improved sodium and potassium excretion to the same extent.
Filippou et al. (2026) conducted an RCT in High-normal blood pressure or grade 1 hypertension (n=240). DASH diet or Mediterranean diet with salt restriction vs. Control group or salt restriction alone was evaluated on 24-hour urine sodium levels at 3 months (MD -9.1 mmol/24 h, p=0.72). In adults with high-normal BP or grade 1 hypertension, the DASH and Mediterranean diets with salt restriction similarly reduced 24-hour urinary sodium excretion (MD -9.1 mmol/24 h; P=0.72).