Effect of DASH vs. mediterranean diet accompanied by a salt restriction on metabolic syndrome and cardiometabolic risk factors in adults with high normal blood pressure or grade 1 hypertension: secondary analyses of a randomized controlled trial

Objective: Lifestyle interventions are recommended as the first-line treatment to control metabolic syndrome components and improve cardiometabolic risk factors. However, studies directly comparing the cardiometabolic effects of the Dietary Approaches to Stop Hypertension (DASH) vs. the Mediterranean diet (MedDiet) accompanied by salt restriction are currently lacking. Thus, with the present secondary analyses of a randomized trial, we aimed to assess the cardiometabolic effects of a 3-month intensive dietary intervention implementing salt restriction alone or on top of the DASH and MedDiet compared to no/minimal intervention in never drug-treated adults with high normal blood pressure (BP) or grade 1 hypertension.

Methods: 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).

Results: According to the intention-to-treat analysis, the DDG and the MDG had lower odds ratio (OR) (95% CI) of metabolic syndrome [0.29 (0.12, 0.72), and 0.15 (0.06, 0.41), respectively] compared to the CG. Moreover, the MDG had lower odds of metabolic syndrome compared to the SRG and lower odds of elevated BP levels than the DDG and the SRG. Moreover, total and LDL-cholesterol, fasting glucose, HbA1c, and systolic/diastolic BP were reduced in all three intervention groups compared to the CG.

Conclusion: On a background of salt restriction, the MedDiet was superior in BP reduction, but the DASH and MedDiet reduced the prevalence of metabolic syndrome to the same extent.