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.

Mediterranean diet and blood pressure reduction in adults with and without hypertension: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND & AIMS: It is unclear whether the Mediterranean diet (MedDiet) has a favorable effect on blood pressure (BP) levels because among randomized controlled trials (RCTs) investigating the MedDiet-mediated BP reduction significant methodological and clinical differences are observed. The purpose of this study was to comprehensively assess the MedDiet BP-effect compared to the usual diet or another dietary intervention (e.g. low-fat diet) in adults with and without hypertension, accounting for methodological and clinical confounders. METHODS: We systematically searched Medline and the Cochrane Collaboration Library databases and identified 35 RCTs (13,943 participants). Random-effects model was used to calculate the mean attained systolic BP (SBP) and diastolic BP (DBP) differences during follow-up. Subgroup and meta-regression analyses were also conducted. RESULTS: Compared to the usual diet and all other active intervention diets the MedDiet reduced SBP and DBP (difference in means: -1.5 mm Hg; 95% CI: -2.8, -0.1; P = 0.035, and -0.9 mm Hg; 95% CI: -1.5, -0.3; P = 0.002, respectively). Compared only to the usual diet the MedDiet reduced SBP and DBP, while compared to all other active intervention diets or only to the low-fat diet the MedDiet did not reduce SBP and DBP. The MedDiet reduced DBP levels to a higher extent in trials with mean baseline SBP ≥130 mm Hg, while both SBP and DBP were reduced more in trials with a mean follow-up period ≥16 weeks. The quality of evidence was rated as moderate for both outcomes according to the grading of recommendations, assessment, development and evaluation (GRADE) approach. CONCLUSIONS: The adoption of the MedDiet was accompanied by a relatively small, but yet significant BP reduction, while higher baseline SBP levels and longer follow-up duration enhanced the BP-lowering effect of the intervention. This meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42020167308. REGISTRY NUMBER: CRD42020167308.

Dietary Approaches to Stop Hypertension (DASH) Diet and Blood Pressure Reduction in Adults with and without Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

The Dietary Approaches to Stop Hypertension (DASH) diet is recognized as an effective dietary intervention to reduce blood pressure (BP). However, among randomized controlled trials (RCTs) investigating the DASH diet-mediated BP reduction, there are significant methodological and clinical differences. The purpose of this study was to comprehensively assess the DASH diet effect on BP in adults with and without hypertension, accounting for underlying methodological and clinical confounders. We systematically searched Medline and the Cochrane Collaboration Library databases and identified 30 RCTs (n = 5545 participants) that investigated the BP effects of the DASH diet compared with a control diet in hypertensive and nonhypertensive adults. Both random-effects and fixed-effect models were used to calculate the mean attained systolic BP (SBP) and diastolic BP (DBP) differences during follow-up. Subgroup and meta-regression analyses were also conducted. Compared with a control diet, the DASH diet reduced both SBP and DBP (difference in means: -3.2 mm Hg; 95% CI: -4.2, -2.3 mm Hg; P < 0.001, and -2.5 mm Hg; 95% CI: -3.5, -1.5 mm Hg; P < 0.001, respectively). Hypertension status did not modify the effect on BP reduction. The DASH diet compared with a control diet reduced SBP levels to a higher extent in trials with sodium intake >2400 mg/d than in trials with sodium intake ≤2400 mg/d, whereas both SBP and DBP were reduced more in trials with mean age <50 y than in trials of older participants. The quality of evidence was rated as moderate for both outcomes according to the Grading of Recommendations, Assessment, Development, and Evaluation approach. The adoption of the DASH diet was accompanied by significant BP reduction in adults with and without hypertension, although higher daily sodium intake and younger age enhanced the BP-lowering effect of the intervention. This meta-analysis was registered at www.crd.york.ac.uk/prospero as CRD42019128120.