Altered Metabolic Profile With Sodium-Restricted Dietary Approaches to Stop Hypertension Diet in Hypertensive Heart Failure With Preserved Ejection Fraction

Potential Mechanisms of Precision Nutrition-Based Interventions for Managing Obesity

Precision nutrition (PN) considers multiple individual-level and environmental characteristics or variables to better inform dietary strategies and interventions for optimizing health, including managing obesity and metabolic disorders. Here, we review the evidence on potential mechanisms-including ones to identify individuals most likely to respond-that can be leveraged in the development of PN interventions addressing obesity. We conducted a review of the literature and included laboratory, animal, and human studies evaluating biochemical and genetic data, completed and ongoing clinical trials, and public programs in this review. Our analysis describes the potential mechanisms related to 6 domains including genetic predisposition, circadian rhythms, physical activity and sedentary behavior, metabolomics, the gut microbiome, and behavioral and socioeconomic characteristics, i.e., the factors that can be leveraged to design PN-based interventions to prevent and treat obesity-related outcomes such as weight loss or metabolic health as laid out by the NIH 2030 Strategic Plan for Nutrition Research. For example, single nucleotide polymorphisms can modify responses to certain dietary interventions, and epigenetic modulation of obesity risk via physical activity patterns and macronutrient intake have also been demonstrated. Additionally, we identified limitations including questions of equitable implementation across a limited number of clinical trials. These include the limited ability of current PN interventions to address systemic influences such as supply chains and food distribution, healthcare systems, racial or cultural inequities, and economic disparities, particularly when designing and implementing PN interventions in low- and middle-income communities. PN has the potential to help manage obesity by addressing intra- and inter-individual variation as well as context, as opposed to "one-size fits all" approaches though there is limited clinical trial evidence to date.

Heart failure symptom burden, dietary intake, and inflammation: An integrative review of the literature

Heart failure (HF) is characterized by high symptom burden including, but not limited to fatigue, dyspnea, and edema. Up to 21.5% of HF patients experience significant depressive symptoms, much higher than 7.1% in adults without HF. Diet, metabolites, and other inflammatory mechanisms have gained notable attention in recent studies for contributions to symptoms in HF. Symptoms for black adults (B/As) with HF are often influenced by lifestyle factors, which may influence their higher mortality rates; few studies address these factors. Distinguishing the links between key elements with diet, inflammation, and symptoms may bring clarity for new dietary strategies in HF clinical care. The purpose of this integrative review is to examine the existing literature regarding relationships among physiologic pathways in HF along with physical and emotional symptoms in the context of inflammation, dietary intake, tumor necrosis factor-alpha (TNF-α), a biomarker of inflammation, and trimethylamine-N-Oxide (TMAO). Based on available evidence, inflammation may be a key link between physical symptoms, diet, depression, TMAO, and TNF-α in persons with HF and warrants further examination to clarify pathological links to solidify evidence for better guidance with dietary modifications. The literature reviewed in this study demonstrates that more work is needed to examine dietary planning, social support, and differences between men and women in the B/A community. Results of this literature review call attention to the essential, personalized care needs related to symptom monitoring and dietary planning which is expected to decrease symptom burden in the HF population.

Metabolomic profiling of the Dietary Approaches to Stop Hypertension diet provides novel insights for the nutritional epidemiology of type 2 diabetes mellitus

Adherence to the Dietary Approaches to Stop Hypertension (DASH) diet is inversely associated with type 2 diabetes mellitus (T2DM) risk. Metabolic changes due to DASH adherence and their potential relationship with incident T2DM have not been described. The objective is to determine metabolite clusters associated with adherence to a DASH-like diet in the Insulin Resistance Atherosclerosis Study cohort and explore if the clusters predicted 5-year incidence of T2DM. The current study included 570 non-diabetic multi-ethnic participants aged 40–69 years. Adherence to a DASH-like diet was determined a priori through an eighty-point scale for absolute intakes of the eight DASH food groups. Quantitative measurements of eighty-seven metabolites (acylcarnitines, amino acids, bile acids, sterols and fatty acids) were obtained at baseline. Metabolite clusters related to DASH adherence were determined through partial least squares (PLS) analysis using R. Multivariable-adjusted logistic regression was used to explore the associations between metabolite clusters and incident T2DM. A group of acylcarnitines and fatty acids loaded strongly on the two components retained under PLS. Among strongly loading metabolites, a select group of acylcarnitines had over 50 % of their individual variance explained by the PLS model. Component 2 was inversely associated with incident T2DM (OR: 0·89; (95 % CI 0·80, 0·99), P-value = 0·043) after adjustment for demographic and metabolic covariates. Component 1 was not associated with T2DM risk (OR: 1·02; (95 % CI 0·88, 1·19), P-value = 0·74). Adherence to a DASH-type diet may contribute to reduced T2DM risk in part through modulations in acylcarnitine and fatty acid physiology.

Adherence to the Dietary Approaches to Stop Hypertension (DASH) diet is associated with low levels of insulin resistance among heart failure patients

BACKGROUND AND AIMS

Heart failure (HF) patients are at risk of developing type 2 diabetes. This study examined the association between adherence to the Dietary Approaches to Stop Hypertension (DASH) diet and insulin resistance among U.S. adults with HF.

METHODS AND RESULTS

Using data from National Health and Nutrition Examination Survey 1999-2016 cycles, we included 348 individuals aged 20+ years with HF and no history of diabetes. DASH diet adherence index quartile 1 indicated the lowest and quartile 4 indicated the highest adherence. The highest level of insulin resistance was defined by the upper tertile of the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). Associations between level of insulin resistance and DASH diet adherence and its linear trends were examined using logistic regressions. Trend analyses showed that participants in upper DASH diet adherence index quartiles were more likely older, female, non-Hispanic White, of normal weight, and had lower levels of fasting insulin than those in lower quartiles. Median values of HOMA-IR from lowest to highest DASH diet adherence index quartiles were 3.1 (interquartile range, 1.8-5.5), 2.9 (1.7-5.6), 2.1 (1.1-3.7), and 2.1 (1.3-3.5). Multivariable logistic analyses indicated that participants with the highest compared to the lowest DASH adherence showed 77.1% lower odds of having the highest level of insulin resistance (0.229, 95% confidence interval: 0.073-0.716; p = 0.017 for linear trend).

CONCLUSION

Good adherence to the DASH diet was associated with lower insulin resistance among community-dwelling HF patients. Heart healthy dietary patterns likely protect HF patients from developing type 2 diabetes.

Dietary Management of Heart Failure: DASH Diet and Precision Nutrition Perspectives

Heart failure (HF) is a major health care burden increasing in prevalence over time. Effective, evidence-based interventions for HF prevention and management are needed to improve patient longevity, symptom control, and quality of life. Dietary Approaches to Stop Hypertension (DASH) diet interventions can have a positive impact for HF patients. However, the absence of a consensus for comprehensive dietary guidelines and for pragmatic evidence limits the ability of health care providers to implement clinical recommendations. The refinement of medical nutrition therapy through precision nutrition approaches has the potential to reduce the burden of HF, improve clinical care, and meet the needs of diverse patients. The aim of this review is to summarize current evidence related to HF dietary recommendations including DASH diet nutritional interventions and to develop initial recommendations for DASH diet implementation in outpatient HF management. Articles involving human studies were obtained using the following search terms: Dietary Approaches to Stop Hypertension (DASH diet), diet pattern, diet, metabolism, and heart failure. Only full-text articles written in English were included in this review. As DASH nutritional interventions have been proposed, limitations of these studies are the small sample size and non-randomization of interventions, leading to less reliable evidence. Randomized controlled interventions are needed to offer definitive evidence related to the use of the DASH diet in HF management.

Mitochondrial complex II in intestinal epithelial cells regulates T cell-mediated immunopathology

Intestinal epithelial cell (IEC) damage by T cells contributes to graft-versus-host disease, inflammatory bowel disease and immune checkpoint blockade-mediated colitis. But little is known about the target cell-intrinsic features that affect disease severity. Here we identified disruption of oxidative phosphorylation and an increase in succinate levels in the IECs from several distinct in vivo models of T cell-mediated colitis. Metabolic flux studies, complemented by imaging and protein analyses, identified disruption of IEC-intrinsic succinate dehydrogenase A (SDHA), a component of mitochondrial complex II, in causing these metabolic alterations. The relevance of IEC-intrinsic SDHA in mediating disease severity was confirmed by complementary chemical and genetic experimental approaches and validated in human clinical samples. These data identify a critical role for the alteration of the IEC-specific mitochondrial complex II component SDHA in the regulation of the severity of T cell-mediated intestinal diseases.

Metabolomic Biomarkers of Healthy Dietary Patterns and Cardiovascular Outcomes

PURPOSE OF REVIEW

Healthy dietary patterns are recommended for prevention of CVD. Recently, metabolomics has been used to identify biomarkers of healthy dietary patterns and elucidate mechanisms underlying diet-disease associations. This review provides an overview of approaches to define healthy dietary patterns, discusses important issues related to using metabolomics to describe healthy dietary patterns, and summarizes studies identifying blood metabolites associated with hypothesis-driven healthy dietary patterns and cardiovascular risk factors and incident CVD.

RECENT FINDINGS

We identified 17 studies which reported on blood metabolomic signatures of 5 healthy dietary patterns (Healthy Eating Index, Alternative Healthy Eating Index, the Dietary Approaches to Stop Hypertension diet, Mediterranean diet, vegetarian diet). Four of these studies evaluated associations between diet-related metabolites and cardiovascular outcomes. Many metabolites replicated across different healthy dietary patterns, which suggest that they may represent biomarkers of generally healthy diets. Unsaturated lipids positively associated with healthy dietary patterns were inversely associated with incident CVD, suggesting that they may be a pathway through which diet is associated with a lower risk of CVD. Although many metabolites replicated across cross-sectional studies, few metabolites identified as candidate biomarkers of healthy diets in feeding studies replicated in observational studies. Additionally, limited evidence exists on the ability of diet-related metabolites to predict cardiovascular outcomes. Replication of candidate biomarkers of dietary patterns in different study designs and more studies evaluating the associations between diet-related metabolites and cardiovascular outcomes are needed.

Nutrition as Treatment Modality in Heart Failure

PURPOSE OF REVIEW

This review aims to discuss recent evidence and controversies regarding nutrition as a treatment modality for heart failure (HF) patients.

RECENT FINDINGS

Adequate nutrition is known to promote health-related quality of life by addressing malnutrition and promoting optimal functioning among older adults and has an established role in the prevention of HF; however, evidence is limited on the effects of nutrition as a treatment modality in HF. While guidance of sodium restriction to address fluid overload is an ongoing debate among experts, evidence from case studies and small clinical trials suggest a positive impact of plant-based and Dietary Approaches to Stop Hypertension (DASH) dietary patterns on HF-related pathophysiology, quality of life, hospital admissions, and mortality. More clinical trials are needed to establish an evidence base to support dietary management strategies for patients with HF. Clinical and Translational Science Alliances (CTSAs) may provide infrastructure to overcome enrollment barriers.

Gut microbiota-derived short-chain fatty acids and hypertension: Mechanism and treatment

Hypertension (HTN) is an growing emerging health issue around across the world. In recent years, increasing attention has been paid to the role of dysbacteriosis in HTN and its underlying mechanism. Short-chain fatty acids (SCFAs), which are novel metabolites of intestinal flora, exert substantial regulatory effects on HTN, providing an exciting avenue for novel therapies for this disease. They function primarily by activating transmembrane G protein-coupled receptors and inhibiting histone acetylation. In this review, we discuss the mechanisms underlying the complex interaction between SCFAs and gut microbiota composition to lower blood pressure by regulating the brain-gut and kidney-gut axes, and the role of high-salt diet, immune system, oxidative stress, and inflammatory mechanism in the development of HTN. Furthermore, we also discuss the various treatment strategies for HTN, including diet, antibiotics, probiotics, fecal microflora transplantation, and traditional Chinese medicine. In conclusion, manipulation of SCFAs opens new avenues to improve treatment of HTN.

Clinical significance of nutritional status in patients with chronic heart failure-a systematic review

Chronic heart failure (CHF) and nutritional disorders are recognized as major challenges for contemporary medicine. This study aims to estimate the role of nutritional disorders as risk factors for CHF development and prognostic factors for CHF patients and the outcome of nutritional intervention in CHF. Full-text English articles published between January 2013 and February 2019 available in the PubMed and Scopus databases were considered. Seventy-five prospective, retrospective, and cross-sectional studies as well as meta-analyses on patients with CHF, reporting correlation of their nutritional status with the risk and prognosis of CHF and the outcome of nutritional interventions in CHF were all included. Higher BMI increases the risk of CHF by 15-70%, especially when associated with severe, long-lasting and abdominal obesity. Overweight and obesity are associated with the reduction of mortality in CHF by 24-59% and 15-65%, respectively, and do not affect the outcome of invasive CHF treatment. Malnutrition increases the risk of mortality (by 2- to 10-fold) and the risk of hospitalization (by 1.2- to 1.7-fold). Favorable outcome of nutritional support in CHF patients was reported in a few studies. Nutritional disorders are prevalent in patients with CHF and play a significant role in the incidence, course, and prognosis of the disease. The existence of an "obesity paradox" in patients with CHF was confirmed. Further studies on the effect of nutritional support and body weight reduction in patients with CHF are necessary.

Dietary metabolism, the gut microbiome, and heart failure

Advances in our understanding of how the gut microbiota contributes to human health and diseases have expanded our insight into how microbial composition and function affect the human host. Heart failure is associated with splanchnic circulation congestion, leading to bowel wall oedema and impaired intestinal barrier function. This situation is thought to heighten the overall inflammatory state via increased bacterial translocation and the presence of bacterial products in the systemic blood circulation. Several metabolites produced by gut microorganisms from dietary metabolism have been linked to pathologies such as atherosclerosis, hypertension, heart failure, chronic kidney disease, obesity, and type 2 diabetes mellitus. These findings suggest that the gut microbiome functions like an endocrine organ by generating bioactive metabolites that can directly or indirectly affect host physiology. In this Review, we discuss several newly discovered gut microbial metabolic pathways, including the production of trimethylamine and trimethylamine N-oxide, short-chain fatty acids, and secondary bile acids, that seem to participate in the development and progression of cardiovascular diseases, including heart failure. We also discuss the gut microbiome as a novel therapeutic target for the treatment of cardiovascular disease, and potential strategies for targeting intestinal microbial processes.

Therapy for heart failure with preserved ejection fraction: current status, unique challenges, and future directions

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF. Among elderly women, HFpEF comprises more than 80% of incident HF cases. Adverse outcomes-exercise intolerance, poor quality of life, frequent hospitalizations, and reduced survival-approach those of classic HF with reduced EF (HFrEF). However, despite its importance, our understanding of the pathophysiology of HFpEF is incomplete, and despite intensive efforts, optimal therapy remains uncertain, as most trials to date have been negative. This is in stark contrast to management of HFrEF, where dozens of positive trials have established a broad array of effective, guidelines-based therapies that definitively improve a range of clinically meaningful outcomes. In addition to providing an overview of current management status, we examine evolving data that may help explain this paradox, overcome past challenges, provide a roadmap for future success, and that underpin a wave of new trials that will test novel approaches based on these insights.

Malnutrition in pulmonary arterial hypertension: a possible role for dietary intervention

PURPOSE OF REVIEW

The last decade's progress has been made in the pharmacological treatment of pulmonary arterial hypertension (PAH). The role of nutrition in relation to quality of life in this group of patients is not investigated yet. In addition to avoiding salt and high-fluid intake based on left heart failure diet, there is no evidence-based diet recommendation for PAH.

RECENT FINDINGS

It was recently demonstrated that patients with PAH suffer from malnutrition resulting in iron and vitamin D deficiency and glucose/insulin resistance. Recent experimental studies suggest that besides reduced malabsorption of important nutrients, the microbiome of the gut is also less diverse in PAH. In this review, we summarize the current knowledge on malnutrition and dietary intake in PAH. We discuss the possible underlying mechanisms and discuss novel therapeutic interventions validated in patients with left heart failure.

SUMMARY

Large-scaled studies on dietary interventions are needed in PAH.

Nutritional Interventions in Heart Failure: Challenges and Opportunities

PURPOSE OF REVIEW

There is a growing body of evidence that nutritional factors influence the incidence of heart failure (HF). The current manuscript aims to collate evidence relating to nutritional intervention in the treatment of HF as well as to provide context regarding challenges and opportunities in the field.

RECENT FINDINGS

Despite the accepted importance of nutritional factors relating to cardiovascular disease severity, there is surprisingly little human intervention research regarding dietary intake and HF. Further, existing nutritional interventions in HF were mostly pilot studies with small samples and short follow-up. There is consistent evidence that nutritional factors majorly influence HF. Despite limited research, there is evidence that nutritional modification can rapidly and profoundly influence multiple aspects of HF. There is an urgent need for well-conducted research to ascertain if nutritional modification can alter the long-term course of HF.

Dietary pattern and incidence of chronic kidney disease among adults: a population-based study

Background & Aims

Although dietary patterns have been linked to chronic diseases such as cardiovascular disease, sparse data are available for a relationship between dietary patterns and incident chronic kidney disease (CKD) in West Asian populations. The aim of this study was to evaluate the association of population-based dietary pattern with the risk of incident CKD after 6.1 years of follow-up.

Methods

At baseline, habitual dietary intakes of 1630 participants of the Tehran Lipid and Glucose Study (TLGS) who were free of CKD was assessed by a valid and reliable food-frequency questionnaire. The following three major dietary patterns were identified using a principal components analysis: Lacto-vegetarian dietary pattern, traditional Iranian dietary pattern, and high fat, high sugar dietary pattern. Estimated glomerular filtration rate (eGFR) was calculated, using the Modification of Diet in Renal Disease (MDRD) Study equation and CKD was defined as eGFR < 60 mL/min/1.73m². Odds ratio (OR) using multivariable logistic regression was calculated for the association of incident CKD with the extracted dietary patterns.

Results

After adjusting for age, sex, smoking, total energy intake, physical activity, body mass index, diabetes, and hypertension the OR for participants in the highest compared with those in the lowest tertile of the lacto-vegetarian dietary pattern was 0.57 (95% confidence interval [CI]: 0.41 to 0.80, P-trend = 0.002). In contrast, the high fat, high sugar dietary pattern was positively associated with the incidence of CKD (OR for the third tertile compared with first tertile: 1.46; 95% CI: 1.03-2.09; P-trend = 0.036). Traditional Iranian dietary pattern was not associated with incident CKD.

Conclusion

The high fat, high sugar dietary pattern was associated with significantly increased (46%) odds of incident CKD, whereas a lacto-vegetarian dietary pattern may be protective against the occurrence of CKD by 43%.

Dietary patterns and components to prevent and treat heart failure: a comprehensive review of human studies

Growing evidence has emerged about the role of dietary patterns and components in heart failure (HF) incidence and severity. The objective here is to provide a comprehensive summary of the current evidence regarding dietary patterns/components and HF. A comprehensive search of online databases was conducted using multiple relevant keywords to identify relevant human studies. The Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets have consistently been associated with decreased HF incidence and severity. Regarding specific dietary components, fruit, vegetables, legumes and whole grains appear beneficial. Current evidence suggests that red/processed meats, eggs and refined carbohydrates are harmful, while fish, dairy products and poultry remain controversial. However, there is a notable lack of human intervention trials. The existing but limited observational and interventional evidence from human studies suggests that a plant-based dietary pattern high in antioxidants, micronutrients, nitrate and fibre but low in saturated/trans-fat and Na may decrease HF incidence/severity. Potential mechanisms include decreased oxidative stress, homocysteine and inflammation but higher antioxidant defence and NO bioavailability and gut microbiome modulation. Randomised, controlled trials are urgently required.

Serum untargeted metabolomic profile of the Dietary Approaches to Stop Hypertension (DASH) dietary pattern

Background

The Dietary Approaches to Stop Hypertension (DASH) dietary pattern is recommended for cardiovascular disease risk reduction. Assessment of dietary intake has been limited to subjective measures and a few biomarkers from 24-h urine collections.

Objective

The aim of the study was to use metabolomics to identify serum compounds that are associated with adherence to the DASH dietary pattern.

Design

We conducted untargeted metabolomic profiling in serum specimens collected at the end of 8 wk following the DASH diet (n = 110), the fruit and vegetables diet (n = 111), or a control diet (n = 108) in a multicenter, randomized clinical feeding study (n = 329). Multivariable linear regression was used to determine the associations between the randomized diets and individual log-transformed metabolites after adjustment for age, sex, race, education, body mass index, and hypertension. Partial least-squares discriminant analysis (PLS-DA) was used to identify a panel of compounds that discriminated between the dietary patterns. The area under the curve (C statistic) was calculated as the cumulative ability to distinguish between dietary patterns. We accounted for multiple comparisons with the use of the Bonferroni method (0.05 of 818 metabolites = 6.11 × 10-5).

Results

Serum concentrations of 44 known metabolites differed significantly between participants randomly assigned to the DASH diet compared with both the control diet and the fruit and vegetables diet, which included an amino acid, 2 cofactors and vitamins (n = 2), and lipids (n = 41). With the use of PLS-DA, component 1 explained 29.4% of the variance and component 2 explained 12.6% of the variance. The 10 most influential metabolites for discriminating between the DASH and control dietary patterns were N-methylproline, stachydrine, tryptophan betaine, theobromine, 7-methylurate, chiro-inositol, 3-methylxanthine, methyl glucopyranoside, β-cryptoxanthin, and 7-methylxanthine (C statistic = 0.986).

Conclusions

An untargeted metabolomic platform identified a broad array of serum metabolites that differed between the DASH diet and 2 other dietary patterns. This newly identified metabolite panel may be used to assess adherence to the DASH dietary pattern. This trial was registered at http://www.clinicaltrials.gov as NCT03403166.

An Overview of Metabolic Phenotyping in Blood Pressure Research

PURPOSE OF THE REVIEW

This review presents the analytical techniques, processing and analytical steps used in metabolomics phenotyping studies, as well as the main results from epidemiological studies on the associations between metabolites and high blood pressure.

RECENT FINDINGS

A variety of metabolomic approaches have been applied to a range of epidemiological studies to uncover the pathophysiology of high blood pressure. Several pathways have been suggested in relation to blood pressure including the possible role of the gut microflora, inflammatory, oxidative stress, and lipid pathways. Metabolic changes have also been identified associated with blood pressure lowering effects of diets high in fruits and vegetables and low in meat intake. However, the current body of literature on metabolic profiling and blood pressure is still in its infancy, not fully consistent and requires careful interpretation. Metabolic phenotyping is a promising approach to uncover metabolic pathways associated with high blood pressure and throw light into the complex pathophysiology of hypertension.

Heart failure with preserved ejection fraction in hypertension

PURPOSE OF REVIEW

Hypertension is the most prevalent risk factor in heart failure with preserved ejection fraction (HFpEF) and plays a key role in the disease. The continued lack of effective therapies to improve outcomes in HFpEF underscores the knowledge gaps regarding the pathophysiology of HFpEF. This review builds on fundamental concepts in pressure overload-induced left ventricular modeling, and summarizes recent knowledge gained regarding the mechanisms underlying the transition from hypertensive heart disease to HFpEF.

RECENT FINDINGS

The pathophysiology of hypertensive HFpEF extends beyond the development of left ventricular hypertrophy and diastolic dysfunction to myocardial contractile dysfunction, beyond left atrial structural dilatation to left atrial functional decline, beyond macrovascular stiffening to microvascular dysfunction, beyond central cardiac triggers to systemic endothelial inflammation, beyond fibrosis to titin changes, and beyond collagen deposition to qualitative changes in collagen. The central paradigm involves a systemic proinflammatory state triggering a downstream cascade of cardiac microvascular endothelial activation, oxidative stress, and abnormal myocardial cyclic guanosine monophosphate signaling, leading to microvascular rarefaction, chronic ischemia, fibrosis and progression to HFpEF.

SUMMARY

Recent advances have provided insights into the pathophysiology of HFpEF in hypertension. Such knowledge provides novel opportunities for therapeutic strategies in the treatment of hypertensive HFpEF.

A Review of Plant-based Diets to Prevent and Treat Heart Failure

Evidence supporting the role of nutrition in heart failure (HF) incidence and severity is growing. A comprehensive search of online databases was conducted using relevant keywords to identify human studies including diet and HF. Several plant-based diets have consistently been associated with decreased HF incidence and severity, notably the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets. Several other plant-based dietary patterns, including low-fat diets and the rice diet, also show promise. Higher dietary quality, as assessed using different scores, seems to provide protective qualities. Fruit, vegetables, legumes and wholegrains appear to be beneficial, whereas red/processed meats, eggs and refined carbohydrates appear harmful. Some evidence suggests detrimental effects of dairy products and poultry, but more research is needed. There is observational and interventional evidence that a plant-based diet high in antioxidants, micronutrients, nitrate and fibre but low in saturated/trans fats may decrease the incidence and severity of HF. Potential mechanisms for this include decreased oxidative stress, homocysteine and inflammation levels, as well as higher antioxidant defence and nitric oxide bioavailability with gut microbiome modulation. Well-designed randomised, controlled nutrition intervention trials specific to HF are urgently required.

The association between Dietary Approaches to Stop Hypertension and incidence of chronic kidney disease in adults: the Tehran Lipid and Glucose Study

Background

This study was conducted to examine the association of adherence to the Dietary Approaches to Stop Hypertension (DASH)-style diet with incident chronic kidney disease (CKD) among an Iranian population.

Methods

We followed-up 1630 participants (50.5% women, mean age: 42.8 years) of the Tehran Lipid and Glucose Study for 6.1 years, who were initially free of CKD. Baseline diet was assessed using a valid and reliable 168-item food frequency questionnaire. A DASH-style diet, based on scoring eight components (fruits, vegetables, whole grains, nuts and legumes, low-fat dairy, red and processed meats, sweetened beverages and sodium) was used. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease Study equation and CKD was defined as eGFR <60 mL/min/1.73 m2. Odds ratio (OR) using multivariable logistic regression was reported for the association of incident CKD with DASH-style diet score.

Results

The incidence of CKD among those in the top quintile of the DASH-style diet was 30%, 18% lower than those in the bottom quintile. After controlling for age, sex, smoking, total energy intake, body mass index, eGFR, triglycerides, physical activity, hypertension and diabetes, adherence to the DASH-style diet was found to be inversely associated with incident CKD (OR: 0.41; 95% confidence interval: 0.24-0.70). In addition, higher scores of fruits, whole grains, nuts and legumes, sweetened beverages and sodium were inversely associated with incidence of CKD.

Conclusion

Results revealed that after 6.1 years of follow-up, adherence to the DASH-style diet was associated with a lower risk of incident CKD among adults.

Effects of dietary sodium on metabolites: the Dietary Approaches to Stop Hypertension (DASH)-Sodium Feeding Study

Background: High sodium intake is known to increase blood pressure and is difficult to measure in epidemiologic studies.Objective: We examined the effect of sodium intake on metabolites within the DASH (Dietary Approaches to Stop Hypertension Trial)-Sodium Trial to further our understanding of the biological effects of sodium intake beyond blood pressure.Design: The DASH-Sodium Trial randomly assigned individuals to either the DASH diet (low in fat and high in protein, low-fat dairy, and fruits and vegetables) or a control diet for 12 wk. Participants within each diet arm received, in random order, diets containing high (150 nmol or 3450 mg), medium (100 nmol or 2300 mg), and low (50 nmol or 1150 mg) amounts of sodium for 30 d (crossover design). Fasting blood samples were collected at the end of each sodium intervention. We measured 531 identified plasma metabolites in 73 participants at the end of their high- and low-sodium interventions and in 46 participants at the end of their high- and medium-sodium interventions (N = 119). We used linear mixed-effects regression to model the relation between each log-transformed metabolite and sodium intake. We also combined the resulting P values with Fisher's method to estimate the association between sodium intake and 38 metabolic pathways or groups.Results: Six pathways were associated with sodium intake at a Bonferroni-corrected threshold of 0.0013 (e.g., fatty acid, food component or plant, benzoate, γ-glutamyl amino acid, methionine, and tryptophan). Although 82 metabolites were associated with sodium intake at a false discovery rate ≤0.10, only 4-ethylphenylsufate, a xenobiotic related to benzoate metabolism, was significant at a Bonferroni-corrected threshold (P < 10^-5). Adjustment for coinciding change in blood pressure did not substantively alter the association for the top-ranked metabolites.Conclusion: Sodium intake is associated with changes in circulating metabolites, including gut microbial, tryptophan, plant component, and γ-glutamyl amino acid-related metabolites. This trial was registered at clinicaltrials.gov as NCT00000608.

Modified Mediterranean Diet for Enrichment of Short Chain Fatty Acids: Potential Adjunctive Therapeutic to Target Immune and Metabolic Dysfunction in Schizophrenia?

Growing interest in gut and digestive processes and their potential link to brain and peripheral based inflammation or biobehavioral phenotypes has led to an increasing number of basic and translational scientific reports focused on the role of gut microbiota within the context of neuropsychiatric disorders. However, the effect of dietary modification on specific gut metabolites, in association with immune, metabolic, and psychopathological functioning in schizophrenia spectrum disorders has not been well characterized. The short chain fatty acids (SCFA) acetate, butyrate, and propionate, major metabolites derived from fermentation of dietary fibers by gut microbes, interact with multiple immune and metabolic pathways. The specific pathways that SCFA are thought to target, are dysregulated in cardiovascular disease, type II diabetes, and systemic inflammation. Most notably, these disorders are consistently linked to an attenuated lifespan in schizophrenia. Although, unhealthy dietary intake patterns and increased prevalence of immune and metabolic dysfunction has been observed in people with schizophrenia; dietary interventions have not been well utilized to target immune or metabolic illness. Prior schizophrenia patient trials primarily focused on the effects of gluten free diets. Findings from these studies indicate that a diet avoiding gluten benefits a limited subset of patients, individuals with celiac disease or non-celiac gluten sensitivity. Therefore, alternative dietary and nutritional modifications such as high-fiber, Mediterranean style, diets that enrich the production of SCFA, while being associated with a minimal likelihood of adverse events, may improve immune and cardiovascular outcomes linked to premature mortality in schizophrenia. With a growing literature demonstrating that SCFA can cross the blood brain barrier and target key inflammatory and metabolic pathways, this article highlights enriching dietary intake for SCFA as a potential adjunctive therapy for people with schizophrenia.

Nutrition and Cardiovascular Disease: Finding the Perfect Recipe for Cardiovascular Health

The increasing burden of cardiovascular disease (CVD) despite the progress in management entails the need of more effective preventive and curative strategies. As dietary-associated risk is the most important behavioral factor influencing global health, it appears the best target in the challenge against CVD. Although for many years, since the formulation of the cholesterol hypothesis, a nutrient-based approach was attempted for CVD prevention and treatment, in recent years a dietary-based approach resulted more effective in reducing cardiovascular risk worldwide. After the publication of randomized trials on the remarkable effects of the Mediterranean diet and the Dietary Approach to Stop Hypertension (DASH) diet on CVD, new efforts were put on research about the effects of complex dietary interventions on CVD. The purpose of this paper is to review the evidence on dietary interventions in the prevention and disease modification of CVD, focusing on coronary artery disease and heart failure, the main disease responsible for the enormous toll taken by CVD worldwide.

Gut microbiome-derived metabolites modulate intestinal epithelial cell damage and mitigate graft-versus-host disease

The effect of alterations in intestinal microbiota on microbial metabolites and on disease processes such as graft-versus-host disease (GVHD) is not known. Here we carried out an unbiased analysis to identify previously unidentified alterations in gastrointestinal microbiota-derived short-chain fatty acids (SCFAs) after allogeneic bone marrow transplant (allo-BMT). Alterations in the amount of only one SCFA, butyrate, were observed only in the intestinal tissue. The reduced butyrate in CD326(+) intestinal epithelial cells (IECs) after allo-BMT resulted in decreased histone acetylation, which was restored after local administration of exogenous butyrate. Butyrate restoration improved IEC junctional integrity, decreased apoptosis and mitigated GVHD. Furthermore, alteration of the indigenous microbiota with 17 rationally selected strains of high butyrate-producing Clostridia also decreased GVHD. These data demonstrate a heretofore unrecognized role of microbial metabolites and suggest that local and specific alteration of microbial metabolites has direct salutary effects on GVHD target tissues and can mitigate disease severity.