DASH vs. Mediterranean diet on a salt restriction background in adults with high normal blood pressure or grade 1 hypertension: A randomized controlled trial

Background & aims: Non-pharmacological measures are recommended as the first-line treatment for individuals with high-normal blood pressure (BP) or mild hypertension. Studies directly comparing the BP effects of the Dietary Approaches to Stop Hypertension (DASH) vs. the Mediterranean diet (MedDiet) on a salt restriction background are currently lacking. Thus, our purpose was to assess the BP effects of a 3-month intensive dietary intervention implementing salt restriction either alone or in the context of the DASH, and the MedDiet compared to no/minimal intervention in adults with high normal BP or grade 1 hypertension. Methods: We randomly assigned never drug-treated individuals to a control group (CG, n = 60), a salt restriction group (SRG, n = 60), a DASH diet with salt restriction group (DDG, n = 60), or a MedDiet with salt restriction group (MDG, n = 60). The primary outcome was the attained office systolic BP difference among the randomized arms during follow-up. Results: A total of 240 patients were enrolled, while 204 (85%) completed the study. According to the intention-to-treat analysis, compared to the CG, office and 24 h ambulatory systolic and diastolic BP were reduced in all intervention groups. A greater reduction in the mean office systolic BP was observed in the MDG compared to all other study groups (MDG vs. CG: mean difference = -15.1 mmHg; MDG vs. SRG: mean difference = -7.5 mmHg, and MDG vs. DDG: mean difference = -3.2 mmHg, all P-values <0.001). The DDG and the MDG did not differ concerning the office diastolic BP and the 24 h ambulatory systolic and diastolic BP; however, both diets were more efficient in BP-lowering compared to the SRG. Conclusions: On a background of salt restriction, the MedDiet was superior in office systolic BP-lowering, but the DASH and MedDiet reduced BP to an extent higher than salt restriction alone. (c) 2023 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Automated summary

This study compared the effects of the DASH diet and the Mediterranean diet on blood pressure under a salt restriction background. The results showed that the Mediterranean diet was more effective in lowering office systolic blood pressure, while both the DASH diet and the Mediterranean diet were more effective in lowering blood pressure compared to salt restriction alone.