Effects of dark chocolate on endothelial function in patients with non-alcoholic steatohepatitis

Beverage consumption in patients with metabolic syndrome and its association with non-alcoholic fatty liver disease: a cross-sectional study

Introduction

Previous research has examined the association between coffee and tea consumption and non-alcoholic fatty liver disease (NAFLD). Preclinical studies have indicated the potential hepatoprotective properties of cocoa/chocolate. However, clinical research on the consumption of cocoa/chocolate and soft drinks and their relation to NAFLD, particularly among individuals with metabolic syndrome, is limited. This study primarily aimed to assess the association between beverage consumption and NAFLD in these patients.

Methods

This cross-sectional study enrolled adult patients with metabolic syndrome visited the Medicine Outpatient Department at Siriraj Hospital, Thailand, from November 2011 to January 2013. The exclusion criteria were secondary causes of hepatic steatosis, such as excessive alcohol use, viral hepatitis, or drug-induced hepatitis. Participants completed a 23-item self-administered questionnaire covering their beverage consumption habits, including type, frequency, volume, duration, and additives in drinks, namely, coffee, tea, cocoa/chocolate, and soft drinks. To ensure accurate responses, these questionnaires were supplemented by face-to-face interviews. Ultrasonography was employed early in the methodology to diagnose NAFLD. Univariable analyses were used to compare the beverage consumption behaviors of participants with and without NAFLD. Multivariable logistic regression was used to adjust for potential confounders, including total beverage energy intake, age, anthropometric data, laboratory results, and comorbidities.

Results

This study included 505 patients with metabolic syndrome. Of these, 341 (67.5%, 95%CI: 63.2-71.6%) were diagnosed with NAFLD. The consumption rates of coffee, cocoa/chocolate, and soft drinks were similar between the two groups. However, tea consumption was significantly more common in patients with NAFLD (68.3% vs. 51.8%, p < 0.001). The groups had no significant differences in caffeine intake or total energy intake from beverages. Notably, daily intake of three or more cups of coffee was correlated with a reduced prevalence of NAFLD, with an adjusted odds ratio of 0.35 (95%CI: 0.14-0.89).

Conclusion

This study revealed that patients with metabolic syndrome, irrespective of NAFLD status, exhibited similar patterns of beverage consumption. While no definitive associations were identified between the intake of coffee, tea, cocoa/chocolate, or soft drinks and NAFLD, a notable exception was observed. A higher consumption of coffee (≥3 cups daily) was associated with a lower prevalence of NAFLD.

Non-alcoholic fatty liver disease and compromised endothelial function in people with type 2 diabetes

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) frequently coexists with type 2 diabetes mellitus (T2DM) and synergistically contributes to the development of atherosclerosis. Flow-mediated dilation (FMD) is a commonly used noninvasive test for assessing endothelial function. The main objective of this study was to explore FMD in patients with T2DM with and without NAFLD.

METHODS

In this cross-sectional study, conducted on people with T2DM, NAFLD was defined as controlled attenuation parameter (CAP) score > 302 dB/m. Endothelial dysfunction was detected when arterial FMD of brachial artery was equal or less than 0.7%. Regression analyses were applied to assess factors associated with impaired FMD.

RESULT

A total of 147 patients (72 with NAFLD and 75 without NAFLD) were included in the final analysis. Patients with NAFLD were more likely to develop FMD ≤ 7% (77.8% vs. 58.7%, P = 0.01). In multivariate analysis, NAFLD (OR = 2.581, 95% CI (1.18-5.62), P = 0.017) and hypertension (HTN) (OR = 3.114, 95% CI (1.31-7.35), P = 0.010) were associated with an increased risk of impaired FMD. However, female sex was associated with a decreased risk of impaired FMD (OR = 0.371, 95% CI (0.15-0.87), P = 0.024).

CONCLUSION

NAFLD is associated with endothelial dysfunction in people with T2DM. This risk is comparable with the risk imposed by HTN, highlighting the importance of screening and management of NAFLD in these patients.

Can Chocolate Be Classified as an Ultra-Processed Food? A Short Review on Processing and Health Aspects to Help Answer This Question

Chocolate is a confectionery product whose consumption has increased, particularly dark chocolate. Chocolate is produced with varying amounts of cocoa liquor (CL), cocoa butter (CB) and cocoa powder (CP). The main chocolate types are dark, milk and white. Processing steps for chocolate production are described, and nutritional compositions examined for benefits and risks to health. Chocolate processing comprises steps at farm level, initial industrial processing for production of CL, CB and CP (common for all chocolate types) and mixing with other ingredients (like milk and sugar differing according to chocolate type) for industrial chocolate processing. All chocolate types present similar processing levels, and none involve chemical processing. Nutritional profiles of chocolate products differ according to composition, e.g., dark chocolate contains more CL, and so a higher antioxidant capacity. Chocolate is an energy-dense food rich in bioactive compounds (polyphenols, alkaloids, amino acids). Studies have demonstrated benefits of moderate consumption in reducing cardiovascular risk and oxidative and inflammatory burden, improving cognitive functions, maintaining diversity in gut microbiota, among others. In our view, chocolate should not be classified as an ultra-processed food because of simple processing steps, limited ingredients, and being an important part of a healthy diet when consumed in moderation.

Non-pharmacological management options for MAFLD: a practical guide

Lifestyle changes should be the main basis for any treatment for metabolic dysfunction-associated fatty liver disease (MAFLD), aiming to increase energy expenditure, reduce energy intake and improve the quality of nutrients consumed. As it is a multifactorial disease, approaches such as physical exercise, a better dietary pattern, and possible pharmacological intervention are shown to be more efficient when used simultaneously to the detriment of their applications. The main treatment for MAFLD is a lifestyle change consisting of diet, activity, exercise, and weight loss. The variables for training prescription such as type of physical exercise (aerobic or strength training), the weekly frequency, and the intensity most indicated for the treatment of MAFLD remain uncertain, that is, the recommendations must be adapted to the clinical conditions comorbidities, and preferences of each subject in a way individual. This review addresses recent management options for MAFLD including diet, nutrients, gut microbiota, and physical exercise.

Cocoa seeds and chocolate products interaction with gut microbiota; mining microbial and functional biomarkers from mechanistic studies, clinical trials and 16S rRNA amplicon sequencing

In recent years, gut microbiome has evolved as a focal point of interest with growing recognition that a well-balanced gut microbiota is highly relevant to an individual's health status. The present review provides a mechanistic insight on the effects of cocoa chemicals on the gut microbiome and further reveals in silico biomarkers, taxonomic and functional features that distinguish gut microbiome of cocoa consumers and controls by using 16S rRNA gene sequencing data. The polyphenols in cocoa can change the gut microbiota either by inhibiting the growth of pathogenic bacteria in the gut such as Clostridium perfringens or by increasing the growth of beneficial microbiota in the gut such as Lactobacillus and Bifidobacterium. This paper demonstrates the holistic effect of gut microbiota on cocoa chemicals and how it impacts human health. We present herein the first comprehensive review and analysis of how raw and roasted cocoa and its products can specifically influence gut homeostasis, and likewise, how microbiota metabolizes cocoa chemicals. In addition to that, our 16S rRNA amplicon sequencing analysis revealed that the flavone and flavonols metabolism, aminobenzoate degradation and fatty acid elongation pathways represent the three most important signatures of microbial functions associated with cocoa consumption.

Endothelial Cell Dysfunction and Nonalcoholic Fatty Liver Disease (NAFLD): A Concise Review

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide. It is strongly associated with obesity, type 2 diabetes (T2DM), and other metabolic syndrome features. Reflecting the underlying pathogenesis and the cardiometabolic disorders associated with NAFLD, the term metabolic (dysfunction)-associated fatty liver disease (MAFLD) has recently been proposed. Indeed, over the past few years, growing evidence supports a strong correlation between NAFLD and increased cardiovascular disease (CVD) risk, independent of the presence of diabetes, hypertension, and obesity. This implies that NAFLD may also be directly involved in the pathogenesis of CVD. Notably, liver sinusoidal endothelial cell (LSEC) dysfunction appears to be implicated in the progression of NAFLD via numerous mechanisms, including the regulation of the inflammatory process, hepatic stellate activation, augmented vascular resistance, and the distortion of microcirculation, resulting in the progression of NAFLD. Vice versa, the liver secretes inflammatory molecules that are considered pro-atherogenic and may contribute to vascular endothelial dysfunction, resulting in atherosclerosis and CVD. In this review, we provide current evidence supporting the role of endothelial cell dysfunction in the pathogenesis of NAFLD and NAFLD-associated atherosclerosis. Endothelial cells could thus represent a "golden target" for the development of new treatment strategies for NAFLD and its comorbid CVD.

Flavanol-Rich Cocoa Supplementation Inhibits Mitochondrial Biogenesis Triggered by Exercise

The potential role of cocoa supplementation in an exercise context remains unclear. We describe the effects of flavanol-rich cocoa supplementation during training on exercise performance and mitochondrial biogenesis. Forty-two male endurance athletes at the beginning of the training season received either 5 g of cocoa (425 mg of flavanols) or maltodextrin (control) daily for 10 weeks. Two different doses of cocoa (equivalent to 5 g and 15 g per day of cocoa for a 70 kg person) were tested in a mouse exercise training study. In the athletes, while both groups had improved exercise performance, the maximal aerobic speed increased only in the control group. A mitochondrial DNA analysis revealed that the control group responded to training by increasing the mitochondrial load whereas the cocoa group showed no increase. Oxidative stress was lower in the cocoa group than in the control group, together with lower interleukin-6 levels. In the muscle of mice receiving cocoa, we corroborated an inhibition of mitochondrial biogenesis, which might be mediated by the decrease in the expression of nuclear factor erythroid-2-related factor 2. Our study shows that supplementation with flavanol-rich cocoa during the training period inhibits mitochondrial biogenesis adaptation through the inhibition of reactive oxygen species generation without impacting exercise performance.

Reactive Oxygen Species/Reactive Nitrogen Species as Messengers in the Gut: Impact on Physiology and Metabolic Disorders

Significance: The role of reactive oxygen/nitrogen species as "friend" or "foe" messengers in the whole body is well characterized. Depending on the concentration in the tissue considered, these molecular actors exert beneficial or deleterious impacts leading to a pathological state, as observed in metabolic disorders such as type 2 diabetes and obesity. Recent Advances: Among the tissues impacted by oxidation and inflammation in this pathological state, the intestine is a site of dysfunction that can establish diabetic symptoms, such as alterations in the intestinal barrier, gut motility, microbiota composition, and gut/brain axis communication. In the intestine, reactive oxygen/nitrogen species (from the host and/or microbiota) are key factors that modulate the transition from physiological to pathological signaling. Critical Issues: Controlling the levels of intestinal reactive oxygen/nitrogen species is a complicated balance between positive and negative impacts that is in constant equilibrium. Here, we describe the synthesis and degradation of intestinal reactive oxygen/nitrogen species and their interactions with the host. The development of novel redox-based therapeutics that alter these processes could restore intestinal health in patients with metabolic disorders. Future Directions: Deciphering the mode of action of reactive oxygen/nitrogen species in the gut of obese/diabetic patients could result in a future therapeutic strategy that combines nutritional and pharmacological approaches. Consequently, preventive and curative treatments must take into account one of the first sites of oxidative and inflammatory dysfunctions in the body, that is, the intestine. Antioxid. Redox Signal. 37, 394-415.

Modulation of Oxidative Stress-Induced Senescence during Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease is characterized by disturbed lipid metabolism and increased oxidative stress. These conditions lead to the activation of different cellular response mechanisms, including senescence. Cellular senescence constitutes an important response to injury in the liver. Recent findings show that chronic oxidative stress can induce senescence, and this might be a driving mechanism for NAFLD progression, aggravating the disturbance of lipid metabolism, organelle dysfunction, pro-inflammatory response and hepatocellular damage. In this context, the modulation of cellular senescence can be beneficial to ameliorate oxidative stress-related damage during NAFLD progression. This review focuses on the role of oxidative stress and senescence in the mechanisms leading to NAFLD and discusses the possibilities to modulate senescence as a therapeutic strategy in the treatment of NAFLD.

Endothelial Dysfunction in Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Individuals with nonalcoholic fatty liver disease (NAFLD) are characterized by increased cardiovascular risk. Endothelial dysfunction, a mechanism implicated in those processes, may constitute the missing link in this interaction. Therefore, this systematic review and meta-analysis aims to evaluate the association of endothelial dysfunction, assessed by flow-mediated dilation (FMD) of the brachial artery, with NAFLD. We conducted a systematic literature search for studies assessing the difference in FMD between patients with NAFLD and controls. Exclusion criteria consisted of preclinical studies, studies in children/adolescents, no FMD assessment, and the absence of an NAFLD/control group. The database search identified 96 studies. Following the application of the exclusion criteria, 22 studies were included in the meta-analysis (NAFLD: 2164 subjects; control: 3322 subjects). Compared with controls, patients with NAFLD had significantly lower FMD% values (SMD: −1.37, 95% CI −1.91 to −0.83, p < 0.001, I2: 98%). Results remained unaffected after exclusion of any single study. Subgroup analysis revealed significantly decreased FMD in NAFLD subjects diagnosed with liver ultrasound or liver biopsy compared with method combination or other methods, while no differences were observed according to the chosen cuff inflation threshold, the presence of a significant difference in obesity measures between the groups, or the type of the control group (age- and sex-matched vs. other). Funnel plot asymmetry was not observed. Finally, compared with patients with pure steatosis, individuals with nonalcoholic steatohepatitis had significantly lower FMD (SMD: −0.81, 95% CI −1.51 to −0.31, p = 0.003, I2: 81%). In conclusion, FMD of the brachial artery, indicative of endothelial dysfunction, was significantly reduced in subjects with nonalcoholic fatty liver disease. Patients with nonalcoholic steatohepatitis might be facing a more pronounced endothelial impairment.

Coagulation and Endothelial Dysfunction Associated with NAFLD: Current Status and Therapeutic Implications

Non-alcoholic fatty liver disease (NAFLD) is closely related to insulin resistance, type 2 diabetes mellitus and obesity. It is considered a multisystem disease and there is a strong association with cardiovascular disease and arterial hypertension, which interfere with changes in the coagulation system. Coagulation disorders are common in patients with hepatic impairment and are dependent on the degree of liver damage. Through a review of the literature, we consider and discuss possible disorders in the coagulation cascade and fibrinolysis, endothelial dysfunction and platelet abnormalities in patients with NAFLD.

Cardiovascular Effects of Chocolate and Wine-Narrative Review

The consumption of food for pleasure is mainly associated with adverse health effects. This review was carried out to verify recent reports on the impact of chocolate and wine consumption on cardiovascular health, with a particular focus on atherosclerosis. On one side, these products have proven adverse effects on the cardiovascular system, but on the other hand, if consumed in optimal amounts, they have cardiovascular benefits. The submitted data suggest that the beneficial doses are 30–50 g and 130/250 mL for chocolate and wine, respectively, for women and men. The accumulated evidence indicates that the active ingredients in the products under consideration in this review are phenolic compounds, characterized by anti-inflammatory, antioxidant, and antiplatelet properties. However, there are also some reports of cardioprotective properties of other compounds such as esters, amines, biogenic amines, amino acids, fatty acids, mineral ingredients, and vitamins. Our narrative review has shown that in meta-analyses of intervention studies, consumption of chocolate and wine was positively associated with the beneficial outcomes associated with the cardiovascular system. In contrast, the assessment with the GRADE (Grading of Recommendations Assessment, Development and Evaluation) scale did not confirm this phenomenon. In addition, mechanisms of action of bioactive compounds present in chocolate and wine depend on some factors, such as age, sex, body weight, and the presence of additional medical conditions. Patients using cardiovascular drugs simultaneously with both products should be alert to the risk of pharmacologically relevant interactions during their use. Our narrative review leads to the conclusion that there is abundant evidence to prove the beneficial impact of consuming both products on cardiovascular health, however some evidence still remains controversial. Many authors of studies included in this review postulated that well-designed, longitudinal studies should be performed to determine the effects of these products and their components on atherosclerosis and other CVD (Cardiovascular Disease) disease.

Systematic Bioinformatic Analyses of Nutrigenomic Modifications by Polyphenols Associated with Cardiometabolic Health in Humans-Evidence from Targeted Nutrigenomic Studies

Cardiometabolic disorders are among the leading causes of mortality in the human population. Dietary polyphenols exert beneficial effects on cardiometabolic health in humans. Molecular mechanisms, however, are not completely understood. Aiming to conduct in-depth integrative bioinformatic analyses to elucidate molecular mechanisms underlying the protective effects of polyphenols on cardiometabolic health, we first conducted a systematic literature search to identify human intervention studies with polyphenols that demonstrate improvement of cardiometabolic risk factors in parallel with significant nutrigenomic effects. Applying the predefined inclusion criteria, we identified 58 differentially expressed genes at mRNA level and 5 miRNAs, analyzed in peripheral blood cells with RT-PCR methods. Subsequent integrative bioinformatic analyses demonstrated that polyphenols modulate genes that are mainly involved in the processes such as inflammation, lipid metabolism, and endothelial function. We also identified 37 transcription factors that are involved in the regulation of polyphenol modulated genes, including RELA/NFKB1, STAT1, JUN, or SIRT1. Integrative bioinformatic analysis of mRNA and miRNA-target pathways demonstrated several common enriched pathways that include MAPK signaling pathway, TNF signaling pathway, PI3K-Akt signaling pathway, focal adhesion, or PPAR signaling pathway. These bioinformatic analyses represent a valuable source of information for the identification of molecular mechanisms underlying the beneficial health effects of polyphenols and potential target genes for future nutrigenetic studies.

Role of liver sinusoidal endothelial cells in liver diseases

Liver sinusoidal endothelial cells (LSECs) form the wall of the hepatic sinusoids. Unlike other capillaries, they lack an organized basement membrane and have cytoplasm that is penetrated by open fenestrae, making the hepatic microvascular endothelium discontinuous. LSECs have essential roles in the maintenance of hepatic homeostasis, including regulation of the vascular tone, inflammation and thrombosis, and they are essential for control of the hepatic immune response. On a background of acute or chronic liver injury, LSECs modify their phenotype and negatively affect neighbouring cells and liver disease pathophysiology. This Review describes the main functions and phenotypic dysregulations of LSECs in liver diseases, specifically in the context of acute injury (ischaemia-reperfusion injury, drug-induced liver injury and bacterial and viral infection), chronic liver disease (metabolism-associated liver disease, alcoholic steatohepatitis and chronic hepatotoxic injury) and hepatocellular carcinoma, and provides a comprehensive update of the role of LSECs as therapeutic targets for liver disease. Finally, we discuss the open questions in the field of LSEC pathobiology and future avenues of research.

Redox-related biomarkers in human cardiovascular disease - classical footprints and beyond

Global epidemiological studies show that chronic non-communicable diseases such as atherosclerosis and metabolic disorders represent the leading cause of premature mortality and morbidity. Cardiovascular disease such as ischemic heart disease is a major contributor to the global burden of disease and the socioeconomic health costs. Clinical and epidemiological data show an association of typical oxidative stress markers such as lipid peroxidation products, 3-nitrotyrosine or oxidized DNA/RNA bases with all major cardiovascular diseases. This supports the concept that the formation of reactive oxygen and nitrogen species by various sources (NADPH oxidases, xanthine oxidase and mitochondrial respiratory chain) represents a hallmark of the leading cardiovascular comorbidities such as hyperlipidemia, hypertension and diabetes. These reactive oxygen and nitrogen species can lead to oxidative damage but also adverse redox signaling at the level of kinases, calcium handling, inflammation, epigenetic control, circadian clock and proteasomal system. The in vivo footprints of these adverse processes (redox biomarkers) are discussed in the present review with focus on their clinical relevance, whereas the details of their mechanisms of formation and technical aspects of their detection are only briefly mentioned. The major categories of redox biomarkers are summarized and explained on the basis of suitable examples. Also the potential prognostic value of redox biomarkers is critically discussed to understand what kind of information they can provide but also what they cannot achieve.

The effect of barberry (Berberis vulgaris) consumption on flow-mediated dilation and inflammatory biomarkers in patients with hypertension: A randomized controlled trial

Hypertension is considered as an important cardiovascular risk factor and evidence suggests that hypertension and endothelial dysfunction reinforce each other. Polyphenol-rich foods, such as barberry can reduce the risk of cardiovascular disease. Our aim was to investigate the effects of barberry consumption on vascular function and inflammatory markers in hypertensive subject. In this randomized controlled parallel trial, 84 hypertensive subjects of both genders (aged 54.06 ± 10.19 years; body mass index 28.02 ± 2.18 kg/m2 ) were randomly allocated to consume barberry (10 g/day dried barberry) or placebo for 8 weeks. Before and after the intervention, changes in brachial flow-mediated dilation (FMD) and plasma macrophage/monocyte chemo-attractant protein-1 (MCP-1), vascular cellular adhesion molecule-1, and intracellular adhesion molecule-1 (ICAM-1) were measured. An intention-to-treat analysis was performed. Compared to placebo (n = 42), barberry consumption (n = 42) improved FMD (B [95% CI] was 6.54% [4.39, 8.70]; p < .001) and decreased plasma ICAM-1 (B [95% CI] was -1.61 ng/ml [-2.74, -0.48]; p = .006). MCP-1 was significantly lower in the barberry group compared with the placebo group (B [95% CI] was -37.62 pg/ml [-72.07, -3.17]; p = .033). Our results indicate that barberry consumption improves FMD and has a beneficial effect on plasma ICAM-1 and MCP-1 in hypertensive patients. This trial was registered at the Iranian Registry of Clinical Trial (IRCT) with number IRCT20160702028742N8.

Food and Nutrition in the Pathogenesis of Liver Damage

The liver is an important organ and plays a key role in the regulation of metabolism and in the secretion, storage, and detoxification of endogenous and exogenous substances. The impact of food and nutrition on the pathophysiological mechanisms of liver injury represents a great controversy. Several environmental factors including food and micronutrients are involved in the pathogenesis of liver damage. Conversely, some xenobiotics and micronutrients have been recognized to have a protective effect in several liver diseases. This paper offers an overview of the current knowledge on the role of xenobiotics and micronutrients in liver damage.

Influence of cardiometabolic comorbidities on myocardial function, infarction, and cardioprotection: Role of cardiac redox signaling

The morbidity and mortality from cardiovascular diseases (CVD) remain high. Metabolic diseases such as obesity, hyperlipidemia, diabetes mellitus (DM), non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) as well as hypertension are the most common comorbidities in patients with CVD. These comorbidities result in increased myocardial oxidative stress, mainly from increased activity of nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, mitochondria as well as downregulation of antioxidant defense systems. Oxidative and nitrosative stress play an important role in ischemia/reperfusion injury and may account for increased susceptibility of the myocardium to infarction and myocardial dysfunction in the presence of the comorbidities. Thus, while early reperfusion represents the most favorable therapeutic strategy to prevent ischemia/reperfusion injury, redox therapeutic strategies may provide additive benefits, especially in patients with heart failure. While oxidative and nitrosative stress are harmful, controlled release of reactive oxygen species is however important for cardioprotective signaling. In this review we summarize the current data on the effect of hypertension and major cardiometabolic comorbidities such as obesity, hyperlipidemia, DM, NAFLD/NASH on cardiac redox homeostasis as well as on ischemia/reperfusion injury and cardioprotection. We also review and discuss the therapeutic interventions that may restore the redox imbalance in the diseased myocardium in the presence of these comorbidities.

The Impact of Dietary Patterns and Nutrition in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become one of the most common causes of chronic liver disease worldwide. The prevalence of NAFLD has grown proportionally with the rise in obesity, sedentary lifestyle, unhealthy dietary patterns, and metabolic syndrome. Currently, in the absence of approved pharmacologic treatment, the keystone of treatment is lifestyle modification focused on achieving a weight loss of 7%-10%, cardiovascular exercise, and improving insulin sensitivity. The primary aim of this review is to outline the effect of different dietetic approaches against NAFLD and highlight the important micronutrient components in the management of NAFLD.

Linking biomarkers of oxidative stress and disease with flavonoid consumption: From experimental models to humans

Identification of the links among flavonoid consumption, mitigation of oxidative stress and improvement of disease in humans has significantly advanced in the last decades. This review used (−)-epicatechin (EC) as an example of dietary flavonoids, and inflammation, endothelial dysfunction/hypertension and insulin resistance/diabetes as paradigms of human disease. In these pathologies, oxidative stress is part of their development and/or their perpetuation. Evidence from both, rodent studies and characterization of mechanisms in cell cultures are encouraging and mostly support indirect antioxidant actions of EC and EC metabolites in endothelial dysfunction and insulin resistance. Human studies also show beneficial effects of EC on these pathologies based on biomarkers of disease. However, there is limited available information on oxidative stress biomarkers and flavonoid consumption to allow establishing conclusive associations. The evolving discovery of metabolites that could serve as reliable markers of intake of specific flavonoids constitutes a powerful tool to link flavonoid consumption to disease and prevention of oxidative stress in human populations.

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Flavonoid’s metabolism and concentration determine their antioxidant mechanisms.

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Except for the GI tract, flavonoids are relevant indirect antioxidants in organs and tissues.

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Flavonoid's health effects are not always linked to biomarkers of oxidative stress.

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(‒)-Epicatechin mitigates the redox deregulation involved in hypertension/T2D pathogenesis.

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More human studies will strength links among flavonoids, oxidative stress, and disease.

Impact of Lifestyles (Diet and Exercise) on Vascular Health: Oxidative Stress and Endothelial Function

Healthy lifestyle and diet are associated with significant reduction in risk of obesity, type 2 diabetes, and cardiovascular diseases. Oxidative stress and the imbalance between prooxidants and antioxidants are linked to cardiovascular and metabolic diseases. Changes in antioxidant capacity of the body may lead to oxidative stress and vascular dysfunction. Diet is an important source of antioxidants, while exercise offers many health benefits as well. Recent findings have evidenced that diet and physical factors are correlated to oxidative stress. Diet and physical factors have debatable roles in modulating oxidative stress and effects on the endothelium. Since endothelium and oxidative stress play critical roles in cardiovascular and metabolic diseases, dietary and physical factors could have significant implications on prevention of the diseases. This review is aimed at summarizing the current knowledge on the impact of diet manipulation and physical factors on endothelium and oxidative stress, focusing on cardiovascular and metabolic diseases. We discuss the friend-and-foe role of dietary modification (including different diet styles, calorie restriction, and nutrient supplementation) on endothelium and oxidative stress, as well as the potential benefits and concerns of physical activity and exercise on endothelium and oxidative stress. A fine balance between oxidative stress and antioxidants is important for normal functions in the cells and interfering with this balance may lead to unfavorable effects. Further studies are needed to identify the best diet composition and exercise intensity.

The sweet side of dark chocolate for chronic kidney disease patients

Chocolate is a widely appreciated foodstuff with historical appreciation as a food from the gods. In addition to its highly palatable taste, it is a rich source of (poly)phenolics, which have several proposed salutogenic effects, including neuroprotective anti-inflammatory, anti-oxidant and cardioprotective capabilities. Despite the known benefits of this ancient foodstuff, there is a paucity of information on the effects of chocolate in the context of chronic kidney disease (CKD). This review focusses on the potential salutogenic contribution of chocolate intake, to mitigate inflammatory and oxidative burden in CKD, its potential, for cardiovascular protection and on the maintenance of diversity in gut microbiota, as well as clinical perspectives, on regular chocolate intake by CKD patients.

IMPACT OF CURRENT DIET AT THE RISK OF NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD)

The nonalcoholic fatty liver disease (NAFLD) affects approximately 20%-30% of general population and is even more prevalent among obese individuals. The risk factors mainly associated with NAFLD are diseases related to the metabolic syndrome, genetics and environment. In this review, we provide a literature compilation evaluating the evidence behind dietary components, including calories intake, fat, protein, fibers and carbohydrate, especially fructose which could be a trigger to development and progression of the NAFLD. In fact, it has been demonstrated that diet is an important factor for the development of NAFLD and its association is complex and extends beyond total energy intake.

The effect of cocoa consumption on markers of oxidative stress: A systematic review and meta-analysis of interventional studies

A number of studies have examined the beneficial effects of cocoa consumption on markers of oxidative stress in different population, however, the findings have been inconclusive. Herein, we systematically reviewed available interventional studies to elucidate the overall impact of cocoa consumption on markers of oxidative stress among adult population. PubMed, Cochrane's library, Science Direct, Scopus, Google scholar and ISI web of science databases were searched for all available literature until March 2019 for relevant studies. The Jadad scale was used to assess the quality of each study. A total of 48 studies out of 1402 met the inclusion criteria and were included in our systematic review and 16 of them were entered in meta-analysis. The pooled estimate from the random-effect model showed cocoa consumption significantly reduced malondialdehyde (SMD: -0.71; 95 % CI, -1.41 to -0.01; P = 0.048) and 8-iso-prostaglandin F2α (WMD: -43.76; 95 % CI, -76.25 to -11.28; P = 0.008) but not the other markers of oxidative stress. Our findings support the concept that cocoa consumption plays an important role in the human metabolic pathway through reducing the oxidative stress. In order to draw a firm link between cocoa and oxidative stress, more clinical trials with adequate sample size and sufficient follow-up periods are warranted.

Does Nox2 Overactivate in Children with Nonalcoholic Fatty Liver Disease?

It is unknown whether nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (Nox2) activation is early associated with endotoxemia and liver damage in nonalcoholic fatty liver disease (NAFLD). To address this issue, we evaluated Nox2 activation, oxidative stress, gut permeability, and lipopolysaccharide (LPS) serum levels in 67 children with biopsy-proven NAFLD and 73 controls. Compared with controls, NAFLD patients had higher Nox2 activity, isoprostane, zonulin, and LPS levels. Multivariate linear regression analysis showed that triglycerides, high-density lipoprotein (HDL), homeostatic model assessment-estimated insulin resistance (HOMA-IR), LPS, and isoprostanes were independently associated with Nox2-derivative peptide (sNox2-dp) levels. Within the NAFLD group, patients with nonalcoholic steatohepatitis (NASH) had significant higher levels of sNox2-dp, isoprostanes, LPS, triglycerides, HOMA-IR, fasting glucose and insulin, and lower HDL than those without NASH. Furthermore, sNox2-dp levels were linearly associated with the histological grading of steatosis, inflammation, ballooning, fibrosis, and NAFLD activity score. This study provides evidence that children with NAFLD have Nox2 overactivation compared with controls and significant association with the degree of liver damage. The close relationship between Nox2 and LPS serum levels leads to hypothesize a potential role for gut-derived LPS in eliciting systemic Nox2 activation.

Hazelnut and cocoa spread improves flow-mediated dilatation in smokers

Hazelnut and cocoa spread is an Italian product containing cocoa and hazelnut. Several epidemiological studies suggest that cocoa and hazelnuts cocoa exert beneficial cardiovascular effects. To investigate whether in smokers, hazelnut and cocoa spread elicits artery dilatation via down-regulation of oxidative stress. Flow-mediated dilatation (FMD), oxidative stress (as assessed by serum isoprostanes excretion, Nox2 activation and NO bioavailability) and antioxidant status [as assessed by vitamin E levels, plasma total polyphenols and H₂O₂ breaking down activity (HBA)] were studied in 20 smokers in a crossover, single-blind study. Patients were randomly allocated to 60 g of Hazelnut and cocoa spread or 60 g of milk chocolate (≤ 35% cocoa). FMD, serum isoprostanes, Nox2 activation, NOx, vitamin E, HBA and total polyphenols were assessed at baseline and 2 h after chocolate ingestion. After Hazelnut and cocoa spread intake, FMD and NOx significantly increased (from 4.3 ± 2.8 to 8.0 ± 3.2%, p < 0.001 and from 23.1 ± 5.5 to 32.0 ± 12.6 µM, p = 0.016, respectively); conversely, serum isoprostanes and Nox2 activation significantly decreased (from 302.8 ± 59.8 to 240.7 ± 90.8 pmol/l, p = 0.03 and from 25 ± 4.4 to 22.6 ± 3.2, p = 0.03, respectively). After Hazelnut and cocoa spread intake, serum total polyphenols, vitamin E and HBA significantly increased (from 133.8 ± 49.7 to 202.5 ± 69.5 mg/l GAE, p = 0.001; from 3.56 ± 1.4 to 4.5 ± 1.0 μmol/mmol cholesterol, p = 0.002 and from 63.3 ± 13.2 to 74.2 ± 12.4%, p = 0.003, respectively). No changes in the above variables were observed after milk chocolate intake. A linear correlation analysis shows that Δ (expressed by difference of values between before and after chocolate intake) of FMD correlates with Δ of total polyphenols and Δ of vitamin E. This study shows that Hazelnut and cocoa spread improves FMD with a mechanism potentially involving downregulation of oxidative stress and eventually increased NO generation in smokers.