Effects of the DASH diet on blood pressure in patients with and without metabolic syndrome: results from the DASH trial

The Efficacy of Dietary Approaches to Stop Hypertension (DASH) Diet on Lipid Profile: A Systematic Review and Meta-analysis of Clinical Controlled Trials

BACKGROUND

Dyslipidemia is considered a causal risk factor for coronary heart disease and stroke. Plant-based diets such as dietary approaches to stop hypertension (DASH) have beneficial effects on cardiovascular health. This meta-analysis was conducted to assess the effects of the DASH diet on lipid profiles based on clinical controlled trials.

METHODS

An inclusive online search was performed in medical databases including Web of Science, PubMed, Scopus, and Google Scholar up to October 2021 to identify trials assessing the effect of the DASH diet on lipid profiles.

RESULTS

Seventeen studies comprising 2218 individuals were included in this meta-analysis. In comparison to the control group, following the DASH diet resulted in a significant reduction in serum triglycerides (WMD: -5.539 mg/dl; 95% CI: -8.806, -2.272) and low-density lipoprotein cholesterol (WMD: -6.387 mg/dl; 95% CI: -12.272, -0.501). However, DASH diet could not reduce serum total cholesterol (WMD: -5.793 mg/dl; 95% CI: -12.84, 1.254), high-density lipoprotein cholesterol (WMD: 0.631 mg/dl; 95% CI: -0.749, 2.011), and total cholesterol/high-density lipoprotein cholesterol ratio (WMD: -0.11 mg/dl; 95% CI: -0.27, 0.05).

CONCLUSION

Findings of this meta-analysis showed that following the DASH diet had beneficial effects on serum triglycerides and low-density lipoprotein cholesterol, however, it had no effect on serum total cholesterol and high-density lipoprotein cholesterol levels. Based on these results, the DASH diet can be considered a strategy for the prevention and complementary management of dyslipidemia.

Effectiveness of DASH Diet versus Other Diet Modalities in Patients with Metabolic Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Metabolic syndrome refers to the coexistence of several known cardiovascular risk factors, including insulin resistance, obesity, atherogenic dyslipidemia, and hypertension. These conditions are interrelated and share underlying mediators, mechanisms, and pathways. Improvement in dietary habits has been shown to improve metabolic parameters in patients undergoing treatment with different diets.

METHODS

A systematic search in different databases was realized using the keywords "Metabolic syndrome", "X syndrome", "Dash dietary" and "Dash diet". Finally, six studies were included in this meta-analysis.

RESULTS

All articles comparing the DASH diet vs. other diet modalities reported significant differences in favor of the DASH diet on Systolic blood pressure (SBP) (standardized mean difference [SMD] = -8.06, confidence interval [CI] = -9.89 to -7.32, and p < 0.00001), Diastolic blood pressure (SMD = -6.38, CI = -7.62 to -5.14, and p < 0.00001), Cholesterol HDL (SMD = 0.70, CI = 0.53 to 0.88, and p < 0.00001) and Cholesterol LDL (SMD = -1.29, CI = -1.73 to -0.85, and p < 0.00001) scales.

CONCLUSIONS

The DASH diet has been shown to be beneficial in altered parameters in patients with MS, and the resulting improvements can significantly affect the daily health of these patients. We therefore recommend that professionals who manage these pathologies promote the use of the DASH diet for the management of specific symptoms.

Effects of the Chinese Heart-Healthy Diet (Sichuan Cuisine Version) on the 10-year CVD risk and vascular age: a randomised controlled feeding trial

Sichuan cuisine was previously fitted into the Chinese Heart-Healthy Diet (CHH) trial to verify the antihypertensive effect. Whether the modified Sichuan diet lessens cardiovascular disease (CVD) is not fully explored. We aimed to estimate the effects of the Sichuan version of CHH diet (CHH diet-SC) on the 10-year risk of CVD and vascular age. A single-blinded randomised controlled feeding trial was conducted. General CVD prediction model was used in manners of intention-to-treat and per-protocol set. After a 7-d run-in period, fifty-three participants with pre- and grade I hypertension from local communities were randomised and provided with either CHH diet-SC (n 27) or a control diet (n 26) for 4 weeks. Mean absolute and relative estimated CVD risks were reduced by 4·5 % and 27·9 % in the CHH diet-SC group, and the between-group relative risk reduction was 19·5 % (P < 0·001) using linear mixed-effects models. The sensitivity analysis with datasets and models showed consistent results, and pre-specified factors were not associated with the intervention effects. The vascular age of CHH-SC group was theoretically 4·4 years younger than that of the control group after intervention. Compared with a typical diet, adopting the CHH diet-SC over 1 month significantly reduced 10-year CVD risks and vascular ages among local adults with mild hypertension.

Native opportunities to stop hypertension: study protocol for a randomized controlled trial among urban American Indian and Alaska Native adults with hypertension

Introduction

American Indian and Alaska Native (AI/AN) adults experience disproportionate cardiovascular disease (CVD) morbidity and mortality compared to other races, which may be partly attributable to higher burden of hypertension (HTN). Dietary Approaches to Stop Hypertension (DASH) is a high-impact therapeutic dietary intervention for primary and secondary prevention of CVD that can contribute to significant decreases in systolic blood pressure (BP). However, DASH-based interventions have not been tested with AI/AN adults, and unique social determinants of health warrant independent trials. This study will assess the effectiveness of a DASH-based intervention, called Native Opportunities to Stop Hypertension (NOSH), on systolic BP among AI/AN adults in three urban clinics.

Methods

NOSH is a randomized controlled trial to test the effectiveness of an adapted DASH intervention compared to a control condition. Participants will be aged ≥18 years old, self-identify as AI/AN, have physician-diagnosed HTN, and have elevated systolic BP (≥ 130 mmHg). The intervention includes eight weekly, tailored telenutrition counseling sessions with a registered dietitian on DASH eating goals. Intervention participants will be provided $30 weekly and will be encouraged to purchase DASH-aligned foods. Participants in the control group will receive printed educational materials with general information about a low-sodium diet and eight weekly $30 grocery orders. All participants will complete assessments at baseline, after the 8-week intervention, and again 12 weeks post-baseline. A sub-sample of intervention participants will complete an extended support pilot study with assessments at 6- and 9-months post-baseline. The primary outcome is systolic BP. Secondary outcomes include modifiable CVD risk factors, heart disease and stroke risk scores, and dietary intake.

Discussion

NOSH is among the first randomized controlled trials to test the impact of a diet-based intervention on HTN among urban AI/AN adults. If effective, NOSH has the potential to inform clinical strategies to reduce BP among AI/AN adults.

Clinical trials registration

https://clinicaltrials.gov/ct2/show/NCT02796313, Identifier NCT02796313.

A High-Quality Diet, as Measured by the DASH Score, Is Associated with a Lower Risk of Metabolic Syndrome and Visceral Obesity

The current study was designed to examine the relationship between diet quality, as measured by the Dietary Approaches to Stop Hypertension (DASH) score, and the prevalence of metabolic syndrome (MetS) and its components. The study was cross-sectional in design and enrolled 535 people, including 215 with MetS and 320 without MetS. Using a validated food frequency questionnaire, the DASH diet quality score was counted. The mean age of the MetS group and control subjects was 58.48 ± 14.65 and 58.33 ± 9.26 years, respectively. The study showed that the MetS group had a significantly lower mean total DASH score than the control group (23.13 ± 5.44 vs. 24.62 ± 5.07, p = 0.0023). In addition, it was found that an increase in the total DASH score was associated with a lower risk of MetS (odds ratio [OR] = 0.95, 95% confidence interval [CI] = 0.91-0.99, p = 0.009). In the correlation analysis of the total population, a better-quality diet (higher DASH score) was positively correlated with high-density lipoprotein cholesterol (HDL-c), and negatively correlated with triglyceride (TG) concentration and waist circumference. It was also found that an increase in the total DASH score was associated with a lower risk of abdominal obesity (OR = 0.93, 95% CI = 0.88-0.99, p = 0.017). The results from the analyzed data highlight the potential benefits of following a healthy diet such as DASH.

Food as medicine? Exploring the impact of providing healthy foods on adherence and clinical and economic outcomes

Background

Methods

Results

Conclusion

Strong and Bitter Vegetables from Traditional Cultivars and Cropping Methods Improve the Health Status of Type 2 Diabetics: A Randomized Control Trial

Vegetables rich in bitter-tasting phytochemicals may exert enhanced beneficial effects against key factors associated with type two diabetes (T2D). This study investigates whether selected cultivars of bitter and strong-tasting (BST) Brassica and root vegetables exert greater health benefits on T2D patients compared to equivalent modern mild and sweet tasting (MST) vegetables. A 12-week randomized, controlled, parallel intervention study involved 92 T2D patients, who were allocated three different diets: (1) 500 g daily of bitter and strong-tasting (BST) vegetables; (2) 500 g daily of mild and sweet-tasting (MST) vegetables; (3) 120 g daily MST normal diet (control). Both vegetable diets contained root vegetables and cabbages selected based on sensory differences and content of phytochemicals. Prior to and after the study, all participants underwent an oral glucose tolerance test (OGTT), 24 h blood pressure measurements, DEXA scans, and fasted blood samples. Both diets high in vegetables significantly reduced the participants' BMI, total body fat mass, and HbA1c levels compared to control, but in the BST group, significant differences were also found regarding incremental area under the curve glucose 240 min (OGTT) and fasting glucose levels. A high daily intake of root vegetables and cabbages showed significant health improvements in both vegetable groups. BST vegetables had the greatest impact on insulin sensitivity, body fat mass, and blood pressure compared to control; moreover, they further improved glycemic control compared to MST vegetables.

Role of Dietary Approaches to Stop Hypertension Diet in Risk of Metabolic Syndrome: Evidence from Observational and Interventional Studies

Background:

This systematic review was conducted to review the studies investigating the role of dietary approach to stop hypertension (DASH) diet in prevalence and progression of the metabolic syndrome (MetS) in children, adolescents, and adults.

Methods:

Electronic searches for included studies were performed in MEDLINE, SCOPUS, EMBASE, Cochrane Trial Register, and ISI Web of Science until 30 March 2020. Study selection, data extraction, and quality assessment were fulfilled independently by two reviewers using predefined criteria. Studies were included if they assessed the role of adherence to DASH diet in risk of incidence, prevalence, and development of MetS.

Results:

Twelve eligible studies (eight observational studies and four clinical trials) were identified. Despite methodological heterogeneity, limited statistical power, and the cross-sectional nature of most of observational studies, greater adherence to DASH diet was associated with reduced risk of MetS. However, results for change in metabolic characteristics based on dietary intervention with DASH diet in some interventional studies were somewhat controversial.

Conclusions:

The current study demonstrates that, based on observational studies, greater adherence to a DASH diet is inversely associated with MetS presence and progression. However, more interventional studies are needed in this regard to clarify the exact effect of DASH diet on MetS.

Diet Quality, Saturated Fat and Metabolic Syndrome

Indices reflecting overall diet quality are used globally in research to predict the risk of various diseases and metabolic disorders such as metabolic syndrome (MetS). Such indices are built to measure adherence to current dietary guidelines or to best assess the diet-disease relationship. Although mostly food-based, dietary guidelines often include recommendations to limit saturated fatty acid (SFA) intake in order to prevent cardiovascular diseases. However, not all diet quality indices consider SFA in their definition of diet quality. Additionally, the relationship between SFA consumption and the development of MetS remains unclear. The purpose of this short review was to explore the association between MetS and various diet quality indices and dietary patterns, with a focus on how SFA contributes to these associations.

Nonpharmacologic Interventions for Reducing Blood Pressure in Adults With Prehypertension to Established Hypertension

Background

Nonpharmacologic interventions that modify lifestyle can lower blood pressure (BP) and have been assessed in numerous randomized controlled trials and pairwise meta‐analyses. It is still unclear which intervention would be most efficacious.

Methods and Results

Bayesian network meta‐analyses were performed to estimate the comparative effectiveness of different interventions for lowering BP. From 60 166 potentially relevant articles, 120 eligible articles (14 923 participants) with a median follow‐up of 12 weeks, assessing 22 nonpharmacologic interventions, were included. According to the surface under the cumulative ranking probabilities and Grading of Recommendations Assessment, Development and Evaluation (GRADE) quality of evidence, for adults with prehypertension to established hypertension, high‐quality evidence indicated that the Dietary Approach to Stop Hypertension (DASH) was superior to usual care and all other nonpharmacologic interventions in lowering systolic BP (weighted mean difference, 6.97 mm Hg; 95% credible interval, 4.50–9.47) and diastolic BP (weighted mean difference, 3.54 mm Hg; 95% credible interval, 1.80–5.28). Compared with usual care, moderate‐ to high‐quality evidence indicated that aerobic exercise, isometric training, low‐sodium and high‐potassium salt, comprehensive lifestyle modification, breathing‐control, and meditation could lower systolic BP and diastolic BP. For patients with hypertension, moderate‐ to high‐quality evidence suggested that the interventions listed (except comprehensive lifestyle modification) were associated with greater systolic BP and diastolic BP reduction than usual care; salt restriction was also effective in lowering both systolic BP and diastolic BP. Among overweight and obese participants, low‐calorie diet and low‐calorie diet plus exercise could lower more BP than exercise.

Conclusions

DASH might be the most effective intervention in lowering BP for adults with prehypertension to established hypertension. Aerobic exercise, isometric training, low‐sodium and high‐potassium salt, comprehensive lifestyle modification, salt restriction, breathing‐control, meditation and low‐calorie diet also have obvious effects on BP reduction.

Association of a traditional Mediterranean diet and non-Mediterranean dietary scores with all-cause and cause-specific mortality: prospective findings from the Moli-sani Study

PURPOSE

To evaluate in an Italian general population, the association with mortality of a traditional Mediterranean diet (MD) and non-Mediterranean dietary (non-MD) patterns, and their combined effect, and to test some biomarkers of cardiovascular (CVD) risk as potential mediators of such associations.

METHODS

Longitudinal analysis on 22,849 men and women aged ≥ 35 years, recruited in the Moli-sani Study (2005-2010), followed up for 8.2 years (median). The MD was assessed by the Mediterranean diet score (MDS). The Dietary  Approaches to Stop Hypertension (DASH), the Palaeolithic diet, and the Nordic diet were chosen as reportedly healthy non-MD patterns. Hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated by multivariable Cox regression.

RESULTS

Participants reaching higher MDS or DASH diet score experienced lower risk of both all-cause (HR 0.77; 95% CI 0.66-0.90 and 0.81; 0.69-0.96, respectively, highest vs lowest quartile) and CVD (0.77; 0.59-1.00 and 0.81; 0.69-0.96, respectively) death risk; risk reduction associated with the Palaeolithic diet was limited to total and other cause death, whereas the Nordic diet did not alter risk of mortality. Increasing adherence to MD was associated with higher survival in each stratum of non-MD diets. Biomarkers of glucose metabolism accounted for 7% and 21.6% of the association between either MDS or DASH diet, respectively, with total mortality risk.

CONCLUSIONS

Both the traditional MD and DASH diet may reduce risk of all-cause mortality among Italians, as well as risk of dying from cardiovascular causes. The Palaeolithic diet did not appear to reduce cardiovascular risk, while the Nordic eating pattern was unlikely to be associated with any substantial health advantage.

The effect of dietary approaches to stop hypertension (DASH) diet on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND

Dietary approaches to stop hypertension (DASH) diet is rich in foods that are proposed to be inversely associated with obesity. Therefore, DASH might better affect body weight; however, published data are conflicting.

OBJECTIVE

To assess the effect of DASH on body weight and composition in adults.

METHODS

PubMed, EMBASE, Scopus and Google scholar were searched up to December 2015, for relevant randomized controlled clinical trials. Mean changes in body weight, body mass index (BMI) and waist circumference (WC) were extracted.

RESULTS

Thirteen articles (ten for body weight, six for BMI and two for WC) were eligible. Meta-analysis revealed that adults on DASH diet lose more weight (weighted mean difference [WMD] = -1.42 kg, 95% confidence interval [95%CI]: -2.03, -0.82) in 8-24 weeks, BMI (WMD = -0.42 kg m(-2) , 95%CI: -0.64, -0.20) in 8-52 weeks and WC (WMD = -1.05 cm, 95%CI: -1.61, -0.49) in 24 weeks compared with controls. Low caloric DASH led to even more weight reduction when compared with other low-energy diets. In addition, the effect was greater in overweight/obese participants and when compared with typical (Western or population's usual) diets.

CONCLUSION

DASH diet is a good choice for weight management particularly for weight reduction in overweight and obese participants.

Metabolic syndrome update

The metabolic syndrome is a multiplex risk factor for atherosclerotic cardiovascular disease and type 2 diabetes. It is composed of atherogenic dyslipidemia, elevated blood pressure, insulin resistance and elevated glucose, a pro-thrombotic state, and a pro-inflammatory state. Excess energy intake and concomitant obesity are the major drivers of the syndrome. Lifestyle intervention can reverse metabolic risk factors, but at times, drug therapies or bariatric surgery may be required to control more overt risk factors.

Dietary contributors to hypertension in adults reviewed

Recent national surveys which measured respondents' blood pressure (BP) levels have shown a high prevalence of hypertension amongst the Irish population, with approximately two-thirds of men and over half of women aged 45 years and over affected. Higher prevalence rates are observed with advancing age. Established diet- and lifestyle-related risk factors for hypertension such as high salt intake, high alcohol consumption and physical inactivity are pervasive in Ireland and are believed to contribute significantly to the high national prevalence of this condition. Additional dietary deficits have been implicated in the development of hypertension, however, including low fruit and vegetable intake, low dairy food consumption and low intake of oily fish. Deficiencies of single micro-nutrients such as folate, riboflavin, vitamin C and vitamin D have also been recently recognised as risk factors for hypertension. For each of these factors, there is evidence that the food and nutrient intakes of many Irish adults fall short of the ideal. These dietary and nutritional deficits, when superimposed on Ireland's existing health-subversive behaviours and escalating rates of obesity, constitute a potent constellation of risk factors for hypertension. However, they also represent viable and potentially effective targets for health promotion initiatives. This review aims to describe the main nutritional, dietary and lifestyle contributors to hypertension in Ireland with a view to informing future interventions aimed at alleviating Ireland's burden of hypertensive disease.