Dietary Interventions on Blood Pressure: The Dietary Approaches to Stop Hypertension (DASH) Trials

The Dietary Approaches to Stop Hypertension (DASH) diet may improve health in new ways other than the obviously beneficial cardiovascular effects. The DASH diet may also reduce the risk of some cancers, and the calcium in the dairy products would help to lower the risk of osteoporosis. One of the key things that has been promoted in the DASH studies is that it is made up of regular foods that are available at most grocery stores. Additionally, the DASH diet is consistent with many of the recommendations made by organizations in the United States: the Dietary Guidelines for Americans, the National Cholesterol Education Program's Step 2 Diet, and the National Cancer Institute.     

The DASH diet may have beneficial effects on bone health

Recent data from an ancillary study to the Dietary Approaches to Stop Hypertension (DASH)-Sodium trial suggest that while sodium intake had very little effect on bone metabolism, the DASH diet (over 30 days) significantly reduced markers of bone turnover. This DASH diet-induced reduction in bone turnover, if sustained, may improve bone mineral status.     

The DASH Diet and Cardiometabolic Health and Chronic Kidney Disease: A Narrative Review of the Evidence in East Asian Countries

The rising incidence of cardiometabolic diseases and chronic kidney disease (CKD) is a leading public health problem in East Asia. Diet is an important modifiable risk factor; thus, adopting a healthy diet such as the Dietary Approaches to Stop Hypertension (DASH) diet may help combat these chronic diseases. The DASH diet was originally developed in a U.S. population, and East Asia is demographically and culturally different from the U.S. Therefore, it is important to examine the evidence regarding the DASH diet and chronic disease in this unique population. This narrative review summarizes the evidence on the DASH diet and cardiometabolic health and CKD in East Asia. Culturally-modified DASH diets have been developed in some East Asian countries. Studies suggest the DASH diet is effective at lowering blood pressure in this population, though the long-term benefits remain unclear. Evidence also suggests the DASH diet may reduce the risk of type 2 diabetes and metabolic syndrome. Further research indicates the DASH diet and its components may reduce CKD risk. However, recommending the DASH diet in those who already have CKD is controversial, as it conflicts with current CKD dietary guidelines, especially in advanced CKD. Notably, current intakes in the general population differ from the DASH dietary pattern, suggesting public health efforts would be needed to encourage adoption of the DASH diet.     

Dietary Approaches to Stop Hypertension (DASH) intervention reduces blood pressure among hypertensive African American patients in a neighborhood health care center

The purpose of this study was to pilot-test DASH-Dinner with Your Nutritionist, a university-neighborhood health care center intervention to promote the Dietary Approaches to Stop Hypertension (DASH) diet. Study participants were low-income African American adults (N = 82) with poorly controlled blood pressure. Six groups, each consisting of 12 to 15 participants taking antihypertensive medications, met for 1 to 2 hours per week for 8 weeks. The intervention followed constructs of Social Cognitive Theory and featured dinners based on the DASH diet plan. Blood pressure was significantly lowered (P < .05) among participants who missed no more than 2 of 8 sessions. Extension of the DASH-Dinner model could improve blood pressure control among low-income hypertensive African Americans and reduce health disparities.     

DASH without the dash (of salt) can lower blood pressure

While the debate regarding the effectiveness of dietary sodium restriction raged, the Dietary Approaches to Stop Hypertension (DASH) research group showed that a diet rich in fruits, vegetables, and low-fat dairy products can reduce blood pressure in the general population and people with Stage I hypertension. The original DASH diet did not require either sodium restriction or weight loss--the two traditional dietary tools to control blood pressure--to be effective. A recent study from the DASH research group now finds that coupling the original DASH diet with sodium restriction is more effective than either dietary manipulation alone.     

Effect of Nutritional Status and Dietary Patterns on Human Serum C-Reactive Protein and Interleukin-6 Concentrations

The inflammatory process plays an important role in the pathogenesis of many chronic diseases, such as cardiovascular diseases, diabetes mellitus type 2, and metabolic syndrome. Serum C-reactive protein (CRP) and interleukin-6 (IL-6) are widely tested inflammatory markers involved in the development of these diseases. Several studies indicate a relation between nutritional status and the concentrations of human high-sensitivity CRP and IL-6. Similarly, the role of diet in reducing inflammation and thereby modulating the risk of non-communicable diseases is supported by numerous studies. This review focuses on the effects of the selected nutrition models in humans on the concentrations of CRP and IL-6. It seems that the Mediterranean diet model is most effective in inhibiting inflammation. The Dietary Approaches to Stop Hypertension model and the plant nutrition model also have proven to be beneficial. The data on low-fat and low-carbohydrate diets are inconclusive. Comprehensive studies are necessary, taking into account the cumulative effect of dietary and other factors on the inflammatory process.     

Adherence to the Dietary Approaches to Stop Hypertension (DASH) and risk of Nonalcoholic Fatty Liver Disease

This case–control study was conducted to examine the association between adherence to the Dietary Approaches to Stop Hypertension (DASH) diet and risk of Nonalcoholic Fatty Liver Disease (NAFLD) development in 102 patients with newly diagnosed NAFLD and 204 controls. Adherence to DASH-style diet was assessed using a validated food frequency questionnaire, and a DASH diet score based on food and nutrients emphasized or minimized in the DASH diet. Participants in the top quartile of DASH diet score were 30% less likely to have NAFLD (OR: 0.0.70; 95%?CI: 0.61, 0.80); however, more adjustment for dyslipidemia and body mass index changed the association to non-significant (OR: 0.92; 95%?CI: 0.73, 1.12). In conclusion, we found an inverse relationship between the DASH-style diet and risk of NAFLD. Prospective studies are needed to confirm this association.     

Dietary Pattern and Hypertension: The DASH Study

A recent multicenter study, Dietary Approaches to Stop Hypertension (DASH), demonstrates that a diet emphasizing fruits, vegetables, and low-fat dairy products that provides calcium, magnesium, and potassium at the 75th percentile of American intake produces an antihypertensive effect comparable to that achieved with many pharmacologic interventions.     

Clinical inquiries: What is the dietary treatment for low HDL cholesterol?

Low-carbohydrate diets raise high-density lipoprotein (HDL) cholesterol levels by approximately 10%; soy protein with isoflavones raises HDL by 3% (strength of recommendation [SOR]: C, based on meta-analysis of physiologic parameters). The Dietary Approaches to Stop Hypertension (DASH) diet and multivitamin supplementation raise HDL 21% to 33% (SOR: C, based on single randomized trial each measuring physiologic parameters). No other dietary interventions studied raise HDL (SOR: C, based on meta-analysis of physiologic parameters).     

Adherence to DASH Dietary Pattern and Its Association with Incident Hyperuricemia Risk: A Prospective Study in Chinese Community Residents

Hyperuricemia represents a great burden on global public health, and it is important to provide effective guidance at the level of dietary patterns. We evaluated the association between the Dietary Approaches to Stop Hypertension (DASH) diet and the risk of hyperuricemia in a large-scale, community-based cohort in East China. In total, 45,853 participants that did not have either hyperuricemia nor gout were included and assigned a DASH dietary score based on their baseline dietary intake. They were then divided into five quintiles (Q1–Q5) according to their score, followed by cross-linkages with local health information systems and in-person surveys. Cox proportional hazards models were adopted to calculate hazard ratio (HR) and 95% confidence intervals (CIs). During a median follow-up of 4.54 years, 2079 newly diagnosed hyperuricemia cases were documented. Compared to the DASH Q1 group, the risk of incident hyperuricemia for the Q5 group was significantly reduced by 16% (HR: 0.84; 95% CIs: 0.72–0.97) in the adjusted model. The associations of DASH diet with hyperuricemia appeared stronger (P for interaction <0.001) among participants with 3–4 cardiometabolic diseases at baseline, compared with their counterparts. Our results suggest that the DASH diet could be taken into account in the recognition of risk population and the prevention of hyperuricemia.     

Dietary patterns and blood pressure in African Americans

Hypertension is a highly prevalent risk factor for vascular disease, particularly among African Americans. The Dietary Approaches to Stop Hypertension (DASH) study demonstrated that providing diets with 8-10 fruits and vegetables and 2-3 low-fat dairy foods per day significantly lowered blood pressure. A recent reanalysis showed even stronger effects for African Americans. Studies are needed to translate these findings into methods of effecting dietary change in high-risk populations.     

Reducing hypertensive cardiovascular disease risk of African Americans with diet: focus on the facts

Hypertension is more common and more severe in African Americans than in other population groups in the United States, placing them at increased risk of cardiovascular disease, stroke, and end-stage renal disease. Whereas past efforts to reduce blood pressure (BP) via the diet centered on manipulating isolated nutrients, there are now conclusive data demonstrating that it is not single dietary components but the overall dietary pattern that has the greatest influence on BP. A nutritionally complete diet rich in fruits, vegetables, and low-fat dairy foods has been clearly proven to significantly lower BP in all population groups. This diet, commonly referred to as the Dietary Approaches to Stop Hypertension (DASH) diet, has been tested in randomized, controlled trials emphasizing African American populations and documented the greatest beneficial effects in hypertensive African Americans. Improving diet quality has been shown to be simply implemented without adverse effects such as symptoms of lactose maldigestion. It is also known to beneficially affect other cardiovascular risk factors and is in keeping with dietary recommendations for prevention of some cancers and osteoporosis. This paper reviews the current data relating dietary patterns to BP control, and advocates dietary recommendations that can accomplish their intended objective of enhancing the health of Americans by promoting safe, feasible, and proven-effective means of doing so. In the case of hypertension prevention and treatment, and thus the reduction of cardiovascular disease risk, overall diet quality should be the primary focus of nutritional recommendations.     

Dietary Approaches to Stop Hypertension (DASH) diet: applicability and acceptability to a UK population

Background:  The Dietary Approaches to Stop Hypertension (DASH) diet is widely promoted in the USA for the prevention and treatment of high blood pressure. It is high in fruit and vegetables, low-fat dairy and wholegrain foods and low in saturated fat and refined sugar. To our knowledge, the use of this dietary pattern has not been assessed in a free-living UK population.
Methods:  The DASH diet was adapted to fit UK food preferences and portion sizes. Fourteen healthy subjects followed the adapted DASH diet for 30 days in which they self-selected all food and beverages. Dietary intake was assessed by 5-day food diaries completed before and towards the end of the study. Blood pressure was measured at the beginning and end of the study to assess compliance to the DASH style diet.
Results:  The DASH diet was easily adapted to fit with UK food preferences. Furthermore, it was well tolerated and accepted by subjects. When on the DASH style diet, subjects reported consuming significantly ( P  <   0.01) more carbohydrate and protein and less total fat (5%, 6% and 9% total energy, respectively). Sodium intakes decreased by 860 mg day⁻¹ ( P  <   0.001). Systolic and diastolic blood pressure decreased significantly ( P  <   0.05) by 4.6 and 3.9 mmHg, respectively when on the DASH style diet.
Conclusions:  The DASH style diet was well accepted and was associated with a decrease in blood pressure in normotensive individuals and should be considered when giving dietary advice to people with elevated blood pressure in the UK.     

Dietary AGEs as Exogenous Boosters of Inflammation

Most chronic modern non-transmissible diseases seem to begin as the result of low-grade inflammation extending over prolonged periods of time. The importance of diet as a source of many pro-inflammatory compounds that could create and sustain such a low-grade inflammatory state cannot be ignored, particularly since we are constantly exposed to them during the day. The focus of this review is on specific components of the diet associated with inflammation, specifically advanced glycation end products (AGEs) that form during thermal processing of food. AGEs are also generated in the body in normal physiology and are widely recognized as increased in diabetes, but many people are unaware of the potential importance of exogenous AGEs ingested in food. We review experimental models, epidemiologic data, and small clinical trials that suggest an important association between dietary intake of these compounds and development of an inflammatory and pro-oxidative state that is conducive to chronic diseases. We compare dietary intake of AGEs with other widely known dietary patterns, such as the Mediterranean and the Dietary Approaches to Stop Hypertension (DASH) diets, as well as the Dietary Inflammation Index (DII). Finally, we delineate in detail the pathophysiological mechanisms induced by dietary AGEs, both direct (i.e., non-receptor-mediated) and indirect (receptor-mediated).     

Genome-Wide Association Analysis of Over 170,000 Individuals from the UK Biobank Identifies Seven Loci Associated with Dietary Approaches to Stop Hypertension (DASH) Diet

Diet is a modifiable risk factor for common chronic diseases and mental health disorders, and its effects are under partial genetic control. To estimate the impact of diet on individual health, most epidemiological and genetic studies have focused on individual aspects of dietary intake. However, analysing individual food groups in isolation does not capture the complexity of the whole diet pattern. Dietary indices enable a holistic estimation of diet and account for the intercorrelations between food and nutrients. In this study we performed the first ever genome-wide association study (GWA) including 173,701 individuals from the UK Biobank to identify genetic variants associated with the Dietary Approaches to Stop Hypertension (DASH) diet. DASH was calculated using the 24 h-recall questionnaire collected by UK Biobank. The GWA was performed using a linear mixed model implemented in BOLT-LMM. We identified seven independent single-nucleotide polymorphisms (SNPs) associated with DASH. Significant genetic correlations were observed between DASH and several educational traits with a significant enrichment for genes involved in the AMP-dependent protein kinase (AMPK) activation that controls the appetite by regulating the signalling in the hypothalamus. The colocalization analysis implicates genes involved in body mass index (BMI)/obesity and neuroticism (ARPP21, RP11-62H7.2, MFHAS1, RHEBL1). The Mendelian randomisation analysis suggested that increased DASH score, which reflect a healthy diet style, is causal of lower glucose, and insulin levels. These findings further our knowledge of the pathways underlying the relationship between diet and health outcomes. They may have significant implications for global public health and provide future dietary recommendations for the prevention of common chronic diseases.     

PREMIER--a trial of lifestyle interventions for blood pressure control: intervention design and rationale

Interventions encouraging adoption of healthy diets and increased physical activity are needed to achieve national goals for preventing and treating hypertension, cardiovascular disease, diabetes, and other chronic diseases. PREMIER was a multicenter clinical trial testing the effects of two lifestyle interventions on blood pressure control, compared with advice only. Both interventions implemented established national guidelines for blood pressure control (weight loss, reduced sodium and alcohol intake, and increased physical activity), and one intervention also included the Dietary Approaches to Stop Hypertension (DASH) diet. Both interventions focused on behavioral self-management, motivational enhancement, and personalized feedback. This article describes the design and evaluation approaches for these interventions. Evaluation of multicomponent lifestyle change interventions can help us understand the benefits and difficulties of making multiple lifestyle changes concurrently and the effects such changes can have on blood pressure, particularly in minorities at higher risk for hypertension.     

Chronic Kidney Disease: Role of Diet for a Reduction in the Severity of the Disease

Chronic kidney disease affects ~37 million adults in the US, and it is often undiagnosed due to a lack of apparent symptoms in early stages. Chronic kidney disease (CKD) interferes with the body’s physiological and biological mechanisms, such as fluid electrolyte and pH balance, blood pressure regulation, excretion of toxins and waste, vitamin D metabolism, and hormonal regulation. Many CKD patients are at risk of hyperkalemia, hyperphosphatemia, chronic metabolic acidosis, bone deterioration, blood pressure abnormalities, and edema. These risks may be minimized, and the disease’s progression may be slowed through careful monitoring of protein, phosphorus, potassium, sodium, and calcium, relieving symptoms experienced by CKD patients. In this review, the current Kidney Disease Outcomes Quality Initiative (KDOQI) recommendations are highlighted, reflecting the 2020 update, including explanations for the pathophysiology behind the recommendations. The Dietary Approaches to Stop Hypertension, the Mediterranean diet, and the whole foods plant-based diet are currently being examined for their potential role in delaying CKD progression. Biological explanations for why the whole foods plant-based diet may benefit CKD patients compared to diets that include animal products are examined. Strong evidence continues to support the importance of diet meeting the daily requirement in the prevention and progression of kidney disease, and medical nutrition therapy with a registered dietitian is a critical aspect in medical intervention for CKD.     

Urine and Plasma Metabolome of Healthy Adults Consuming the DASH (Dietary Approaches to Stop Hypertension) Diet: A Randomized Pilot Feeding Study

We aimed to identify plasma and urine metabolites altered by the Dietary Approaches to Stop Hypertension (DASH) diet in a post-hoc analysis of a pilot feeding trial. Twenty adult participants with un-medicated hypertension consumed a Control diet for one week followed by 2 weeks of random assignment to either Control or DASH diet. Non-missing fasting plasma (n = 56) and 24-h urine (n = 40) were used to profile metabolites using untargeted gas chromatography/mass spectrometry. Linear models were used to compare metabolite levels between the groups. In urine, 19 identifiable untargeted metabolites differed between groups at p < 0.05. These included a variety of phenolic acids and their microbial metabolites that were higher during the DASH diet, with many at false discovery rate (FDR) adjusted p < 0.2. In plasma, eight identifiable untargeted metabolites were different at p < 0.05, but only gamma-tocopherol was significantly lower on DASH at FDR adjusted p < 0.2. The results provide insights into the mechanisms of benefit of the DASH diet.     

Diet Quality Is Associated with Glucose Regulation in a Cohort of Young Adults

Young-onset type 2 diabetes and prediabetes is a growing epidemic. Poor diet is a known risk factor for T2D in older adults, but the contribution of diet to risk factors for T2D is not well-described in youth. Our objective was to examine the relationship of diet quality with prediabetes, glucose regulation, and adiposity in young adults. A cohort of young adults (n = 155, age 17–22) was examined between 2014–2018, and 89 underwent a follow-up visit from 2020–2022. At each visit, participants completed diet and body composition assessments and an oral glucose tolerance test. Adherence to four dietary patterns was assessed: Dietary Approaches to Stop Hypertension (DASH), Healthy Eating Index (HEI), Mediterranean diet, and Diet Inflammatory Index (DII). Regression analyses were used to determine adjusted associations of diet with risk for prediabetes and adiposity. Each one-point increase in DASH or HEI scores between visits reduced the risk for prediabetes at follow-up by 64% (OR, 95% CI: 0.36, 0.17–0.68) and 9% (OR, 95% CI: 0.91, 0.85–0.96), respectively. The DASH diet was inversely associated with adiposity, while DII was positively associated with adiposity. In summary, positive changes in HEI and DASH scores were associated with reduced risk for prediabetes in young adults.     

Dietary quality assurance processes of the DASH-Sodium controlled diet study

A thorough quality assurance (QA) program upholds the integrity of nutrition research studies by yielding reliable data and results. Continually evaluating the implementation of a procedure against a goal and making adjustments when needed enhance the quality of a study's conduct and outcomes. Controlled diet studies require QA processes at various steps beginning with the screening of study participants, through diet preparation and delivery to data collection. Staff training and observations with monitoring activities, are important so tasks are completed according to protocol. When several clinical sites participate as partners in a controlled diet study, uniform procedures must be followed and a formal standardized QA program will assist. The Dietary Approaches to Stop Hypertension (DASH)-Sodium study employed such a program, described in this article, that included training staff, observing procedures, monitoring data for completeness and accuracy, evaluating processes, giving feedback, and documenting that tasks were done according to protocol. Furthermore, QA processes were used in the areas of participant screening, orientation, diet adherence, food procurement and preparation, and exit interviews. Other researchers may implement similar activities to ensure quality in their nutrition research programs.