Mechanisms by which cocoa flavanols improve metabolic syndrome and related disorders

Cocoa flavanol supplementation in optimizing post-exercise glycemic control in rats with normoglycemia or diabetes mellitus: findings from the ECODIA study

OBJECTIVE

This study investigated the acute effects of cocoa flavanol (CF) supplementation on glucose homeostasis, aerobic performance, and lactate concentration in rats with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and normoglycemia (NORM).

MATERIALS AND METHODS

The study included 28 male Wistar rats (220-290 g). Induction of T1DM (n = 8) was achieved through intraperitoneal injection of streptozotocin, while T2DM (n = 10) was induced using an ad libitum high-fat diet combined with a fructose-rich beverage. The rats in the NORM group (n = 10) received a standard diet for 30 days. Two experiments were conducted: (1) T1DM rats performed two successive 30-minute treadmill runs below the anaerobic threshold and (2) T2DM and NORM rats underwent two incremental maximal treadmill running tests, both after CF or placebo supplementation. Blood glucose concentrations were measured from pre-exercise to 60 minutes post-exercise.

RESULTS

Glycemic reduction at 60 minutes post-exercise was significantly potentiated by CF compared with placebo supplementation in T1DM, T2DM, and normoglycemic rats (p < 0.05 for all). In T2DM rats, CF induced a glycemic response comparable to the NORM placebo-supplemented condition. These effects of CF persisted despite variations in aerobic performance or lactate concentration after incremental exercise.

CONCLUSION

Supplementation with CF prior to physical exercise elicited a pronounced post-aerobic exercise glycemic reduction. This represents a promising strategy for mitigating the duration of hyperglycemia exposure after physical exercise.

Dark Chocolate Elevates Resting Energy Expenditure in Postmenopausal Women

Several recent reports have indicated positive health benefits of consuming (-)-epicatechin-rich cocoa products. Postmenopausal women are predisposed to reduced metabolism due to decreased levels and activity of the sex hormones estrogen, progesterone, and estradiol. The purpose of this study was to investigate the influence of dark chocolate consumption on resting and exercise metabolism in postmenopausal women. Using a randomized, double-blind design, 26 postmenopausal participants were assigned to a 30-day supplementation with 20-g per day of 72% dark chocolate (DC) or calorically matched white chocolate (WC). Before supplementation, participants underwent two control trials for assessments (PRE1, PRE2) of resting energy expenditure (REE) and exercise energy expenditure (EEE). Following the PRE2 assessment, participants were randomized and supplemented for 30 days, after which they repeated the assessments for REE and EEE. PRE1 and PRE2 REE and EEE were not significantly different within or between groups (REE: PRE1 DC 1215± 170, WC 1127 ± 174, p=0.662; PRE2 DC 1211 ± 174, WC 1145 ± 165 kcal/d, p=0.720; EEE: PRE1 DC 3.67 ± 0.72, WC 3.40 ± 0.81, p=0.665; PRE2 DC 3.41 ± 0.88, WC 3.39 ± 0.73kcal/min, p=0.373). Post-supplementation REE was significantly increased by 3.2% in the DC group (Pre-Post change: DC 38.6 ± 49, WC -15 ± 31.2 kcal per day, p =0.039, Cohen's d= 0.724 [95% CI: 0.078, 1.513]). These results indicate that DC supplementation in postmenopausal women was associated with a significant 3.2% increase in REE with no significant influence on EEE.

Natural Products and Diabetes: (-)-Epicatechin and Mechanisms Involved in the Regulation of Insulin Sensitivity

Type 2 diabetes (T2D) is a disease that occurs when cells do not respond normally to insulin, a condition called insulin resistance, which leads to high blood glucose levels. Although it can be treated pharmacologically, dietary habits beyond carbohydrate restriction can be highly relevant in the management of T2D. Emerging evidence supports the possibility that natural products (NPs) could contribute to managing blood glucose or counteract the undesirable effects of hyperglycemia and insulin resistance. This chapter summarizes the relevant preclinical evidence involving the flavonoid (-)-epicatechin (EC) in the optimization of glucose homeostasis, reducing insulin resistance and/or diabetes-associated disorders. Major effects of EC are observed on (i) intestinal functions, including digestive enzymes, glucose transporters, microbiota, and intestinal permeability, and (ii) redox homeostasis, including oxidative stress and inflammation. There is still a need for further clinical studies to confirm the in vitro and rodent data, allowing recommendations for EC, particularly in prediabetic and T2D patients. The collection of similar data and the lack of clinical evidence for EC is also applicable to other NPs.

The high-fat diet and low-dose streptozotocin type-2 diabetes model induces hyperinsulinemia and insulin resistance in male but not female C57BL/6J mice

Translation of preclinical findings on the efficacy of dietary interventions for metabolic disease to human clinical studies is challenging due to the predominant use of male rodents in animal research. Our objective was to evaluate a combined high-fat (HF) diet and low-dose streptozotocin (STZ) model for induction of type-2 diabetes (T2D) in male and female C57BL/6J mice. We hypothesized that T2D biomarkers would differ significantly between sexes. Mice were administered either a low-fat (LF) diet (10% kcal from fat), or HF diet (60% kcal from fat) + STZ injections (30 mg/kg/d for 3 days). Both sexes gained weight and developed impaired postprandial oral glucose tolerance on the HF+STZ treatment compared to LF. Only male mice on HF + STZ developed fasting hyperglycemia, fasting hyperinsulinemia and insulin resistance, suggesting that the underlying causes of postprandial hyperglycemia differed between sexes. Principal component analysis of measures such as body weights, glucose and insulin concentrations indicated metabolic derangement for males only on HF+STZ treatment, while LF group males and both groups of females significantly overlapped. Based on our data, we accept our hypothesis that the combined high-fat diet and low-dose STZ model for T2D phenotypes differs significantly in its effect on mice based on sex. The HF diet + low-dose STZ model is not useful for studying insulin resistance in females. Other models are needed to model T2D, and study the effects of dietary interventions in this disease, in females. Sexual dimorphism remains a significant challenge for both preclinical and clinical research.

The Role of Intermittent Fasting on Metabolic Syndrome: A Systematic Review and Meta-Analysis

Intermittent fasting has gained popularity as a dietary intervention to improve metabolic health. Metabolic syndrome may benefit from intermittent fasting by improving weight, cholesterol levels, blood pressure (BP), and glucose control. This study aims to assess the effects of intermittent fasting on weight, BMI, cholesterol levels, BP, and glucose in individuals with metabolic syndrome. This systematic review and meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and included 11 studies examining the effects of intermittent fasting on metabolic syndrome. A comprehensive search of PubMed and Google Scholar identified 6,451 studies, of which 11 met the inclusion criteria. Data on weight, BMI, cholesterol, BP, and glucose levels were extracted, and a random effects meta-analysis was conducted to assess outcomes. Analysis showed significant improvements in weight, with a mean reduction of 3.59 kg (95% CI: -4.59 to -2.59, p < 0.0001) and a decrease in BMI of 1.39 kg/m2 (95% CI: -1.87 to -0.92, p < 0.0001). Low-density lipoprotein (LDL) cholesterol levels dropped by 56.22 mg/dL (95% CI: -80.14 to -32.29, p < 0.0001), and systolic BP decreased by 5.54 mmHg (95% CI: -7.55 to -3.53, p < 0.0001). However, high-density lipoprotein (HDL) cholesterol showed minimal changes, and glucose levels remained stable. Intermittent fasting led to significant reductions in weight, BMI, LDL cholesterol, and BP, making it a promising non-pharmacological strategy for managing metabolic syndrome. Further research is needed to explore long-term effects and optimal fasting protocols for different populations.

Impact of Diet and Nutrition in Patients with Acne Vulgaris

Acne vulgaris is a widespread a chronic inflammatory dermatosis that affects millions of people around the world, which has a significant influence on patients' standard of living. The progression of this dermatosis results in the appearance of inflammatory and non-inflammatory changes, and, in severe cases, disfiguring scars and hyperpigmentation. The aetiopathogenesis of acne is complex. It involves a complex interaction of many different factors, both endo- and exogenous in their effect on the hair and sebaceous unit. Genetic predisposition, hormones, the skin and gut microbiome, psychological stress, air pollutants, aggressive facial products, and certain medications are cited as factors influencing acne formation. The link between nutrition and acne is extensively debated for many years and is still relatively controversial. Diet is commonly recognised to have a direct relationship with certain biochemical markers and the transcription of genes related to sebaceous gland function, and the proliferation of bacteria and inflammation that encourage the progression of the disease. In this review, the authors take a closer look at the existing scientific reports on the involvement of nutrition in the development of acne vulgaris.

Phytochemicals and Vitamin D for a Healthy Life and Prevention of Diseases

A variety of phytocompounds contained in medical plants have been used as medication, including Kampo (traditional Japanese) medicine. Phytochemicals are one category of the chemical compounds mainly known as antioxidants, and recently, their anti-inflammatory effects in preventing chronic inflammation have received much attention. Here, we present a narrative review of the health-promotion and disease-prevention effects of phytochemicals, including polyphenols, the latter of which are abundant in onions, oranges, tea, soybeans, turmeric, cacao, and grapes, along with the synergetic effects of vitamin D. A phenomenon currently gaining popularity in Japan is finding non-disease conditions, so-called ME-BYO (mibyou) and treating them before they develop into illnesses. In addition to lifestyle-related diseases such as metabolic syndrome and obesity, dementia and frailty, commonly found in the elderly, are included as underlying conditions. These conditions are typically induced by chronic inflammation and might result in multiple organ failure or cancer if left untreated. Maintaining gut microbiota is important for suppressing (recently increasing) intestinal disorders and for upregulating immunity. During the COVID-19 pandemic, the interest in phytochemicals and vitamin D for disease prevention increased, as viral and bacterial infection to the lung causes fatal inflammation, and chronic inflammation induces pulmonary fibrosis. Furthermore, sepsis is a disorder inducing severe organ failure by the infection of microbes, with a high mortality ratio in non-coronary ICUs. However, antimicrobial peptides (AMPs) working using natural immunity suppress sepsis at the early stage. The intake of phytochemicals and vitamin D enhances anti-inflammatory effects, upregulates immunity, and reduces the risk of chronic disorders by means of keeping healthy gut microbiota. Evidence acquired during the COVID-19 pandemic revealed that daily improvement and prevention of underlying conditions, in terms of lifestyle-related diseases, is very important because they increase the risk of infectious diseases. This narrative review discusses the importance of the intake of phytochemicals and vitamin D for a healthy lifestyle and the prevention of ME-BYO, non-disease conditions.

The synergistic ramification of insoluble dietary fiber and associated non-extractable polyphenols on gut microbial population escorting alleviation of lifestyle diseases

Most of the pertinent research which aims at exploring the therapeutic effects of polyphenols usually misapprehends a large fraction of non-extractable polyphenols due to their poor aqueous-organic solvent extractability. These polymeric polyphenols (i.e., proanthocyanins, hydrolysable tannins and phenolic acids) possess a unique property to adhere to the food matrix polysaccharides and protein sowing to their structural complexity with high glycosylation, degree of polymerization, and plenty of hydroxyl groups. Surprisingly resistance to intestinal absorption does not hinder its bioactivity but accelerates its functionality manifolds due to the colonic microbial catabolism in the gastrointestinal tract, thereby protecting the body from local and systemic inflammatory diseases. This review highlights not only the chemistry, digestion, colonic metabolism of non-extractable polyphenols (NEPP) but also summarises the synergistic effect of matrix-bound NEPP exerting local as well as systemic health benefits.

Bioavailable Microbial Metabolites of Flavanols Demonstrate Highly Individualized Bioactivity on In Vitro β-Cell Functions Critical for Metabolic Health

Dietary flavanols are known for disease preventative properties but are often poorly absorbed. Gut microbiome flavanol metabolites are more bioavailable and may exert protective activities. Using metabolite mixtures extracted from the urine of rats supplemented with flavanols and treated with or without antibiotics, we investigated their effects on INS-1 832/13 β-cell glucose stimulated insulin secretion (GSIS) capacity. We measured insulin secretion under non-stimulatory (low) and stimulatory (high) glucose levels, insulin secretion fold induction, and total insulin content. We conducted treatment-level comparisons, individual-level dose responses, and a responder vs. non-responder predictive analysis of metabolite composition. While the first two analyses did not elucidate treatment effects, metabolites from 9 of the 28 animals demonstrated significant dose responses, regardless of treatment. Differentiation of responders vs. non-responder revealed that levels of native flavanols and valerolactones approached significance for predicting enhanced GSIS, regardless of treatment. Although treatment-level patterns were not discernable, we conclude that the high inter-individual variability shows that metabolite bioactivity on GSIS capacity is less related to flavanol supplementation or antibiotic treatment and may be more associated with the unique microbiome or metabolome of each animal. These findings suggest flavanol metabolite activities are individualized and point to the need for personalized nutrition practices.

Changes in bioactive compounds during fermentation of cocoa (Theobroma cacao) harvested in Amazonas-Peru

Cocoa (Theobroma cacao) is the main raw material for the production of chocolate; it is considered the food of the gods, as it possesses a diversity of bioactive compounds beneficial to human health. The abundance of bioactive compounds, among others, is conditioned by the post-harvest processing of cocoa beans, and fermentation is a major step in this regard. Consequently, this research evaluated the changes in phenolic compounds and methylxanthines occurred in the fermentation of Criollo and CCN-51 cocoa beans, varieties of great commercial interest for the cocoa-growing areas of Peru. For this purpose, samples were taken every 12 h of cocoa beans under fermentation for 204 h in which phenols (gallic acid, caffeic acid, catechin, and epicatechin) and methylxanthines (theobromine, caffeine and theophylline) were quantified by ultra-high performance liquid chromatography (UHPLC); total polyphenols by Folin Ciocalteu; antioxidant capacity by DPPH free radical capture method; total anthocyanins; pH; titratable acidity; and fermentation rate of beans. We found that during fermentation, phenolic content, antioxidant activity, and methylxanthines of cocoa beans decreased; on the other hand, the anthocyanin content increased slightly. Indeed, at distinctly degree, fermentation influences bioactive compounds in cocoa beans, depending on the variety cultivated.

"An apple a day keeps the doctor away": The potentials of apple bioactive constituents for chronic disease prevention

Apples are rich sources of selected micronutrients (e.g., iron, zinc, vitamins C and E) and polyphenols (e.g., procyanidins, phloridzin, 5′‐caffeoylquinic acid) that can help in mitigating micronutrient deficiencies (MNDs) and chronic diseases. This review provides an up‐to‐date overview of the significant bioactive compounds in apples together with their reported pharmacological actions against chronic diseases such as diabetes, cancer, and cardiovascular diseases. For consumers to fully gain these health benefits, it is important to ensure an all‐year‐round supply of highly nutritious and good‐quality apples. Therefore, after harvest, the physicochemical and nutritional quality attributes of apples are maintained by applying various postharvest treatments and hurdle techniques. The impact of these postharvest practices on the safety of apples during storage is also highlighted. This review emphasizes that advancements in postharvest management strategies that extend the storage life of apples should be optimized to better preserve the bioactive components crucial to daily dietary needs and this can help improve the overall health of consumers.

Chronic Consumption of Cocoa Rich in Procyanidins Has a Marginal Impact on Gut Microbiota and on Serum and Fecal Metabolomes in Male Endurance Athletes

Cocoa is used in the sports world as a supplement, although there is no consensus on its use. We investigated the effect of cocoa intake on intestinal ischemia (intestinal fatty acid-binding protein (I-FABP)), serum lipopolysaccharide (LPS) levels, gastrointestinal symptoms, and gut microbiota in endurance athletes during their training period on an unrestricted diet. We also performed a metabolomics analysis of serum and feces after a bout of exercise before and after supplementation. Cocoa consumption had no effect on I-FABP, LPS, or gastrointestinal symptoms. Cocoa intake significantly increased the abundance of Blautia and Lachnospira genera and decreased the abundance of the Agathobacter genus, which was accompanied by elevated levels of polyphenol fecal metabolites 4-hydroxy-5-(phenyl)-valeric acid and O-methyl-epicatechin-O-glucuronide. Our untargeted approach revealed that cocoa had no significant effects on serum and fecal metabolites and that its consumption had little impact on the metabolome after a bout of physical exercise.

Dietary Cocoa Flavanols Enhance Mitochondrial Function in Skeletal Muscle and Modify Whole-Body Metabolism in Healthy Mice

Mitochondrial dysfunction is widely reported in various diseases and contributes to their pathogenesis. We assessed the effect of cocoa flavanols supplementation on mitochondrial function and whole metabolism, and we explored whether the mitochondrial deacetylase sirtuin-3 (Sirt3) is involved or not. We explored the effects of 15 days of CF supplementation in wild type and Sirt3^-/- mice. Whole-body metabolism was assessed by indirect calorimetry, and an oral glucose tolerance test was performed to assess glucose metabolism. Mitochondrial respiratory function was assessed in permeabilised fibres and the pyridine nucleotides content (NAD⁺ and NADH) were quantified. In the wild type, CF supplementation significantly modified whole-body metabolism by promoting carbohydrate use and improved glucose tolerance. CF supplementation induced a significant increase of mitochondrial mass, while significant qualitative adaptation occurred to maintain H₂O₂ production and cellular oxidative stress. CF supplementation induced a significant increase in NAD⁺ and NADH content. All the effects mentioned above were blunted in Sirt3^-/- mice. Collectively, CF supplementation boosted the NAD metabolism that stimulates sirtuins metabolism and improved mitochondrial function, which likely contributed to the observed whole-body metabolism adaptation, with a greater ability to use carbohydrates, at least partially through Sirt3.

Timing of chocolate intake affects hunger, substrate oxidation, and microbiota: A randomized controlled trial

Eating chocolate in the morning or in the evening/at night, may differentially affect energy balance and impact body weight due to changes in energy intake, substrate oxidation, microbiota (composition/function), and circadian-related variables. In a randomized controlled trial, postmenopausal females (n = 19) had 100 g of chocolate in the morning (MC), in the evening/at night (EC), or no chocolate (N) for 2 weeks and ate any other food ad libitum. Our results show that 14 days of chocolate intake did not increase body weight. Chocolate consumption decreased hunger and desire for sweets (P < .005), and reduced ad libitum energy intake by ~300 kcal/day during MC and ~150 kcal/day during EC (P = .01), but did not fully compensate for the extra energy contribution of chocolate (542 kcal/day). EC increased physical activity by +6.9%, heat dissipation after meals +1.3%, and carbohydrate oxidation by +35.3% (P < .05). MC reduced fasting glucose (4.4%) and waist circumference (-1.7%) and increased lipid oxidation (+25.6%). Principal component analyses showed that both timings of chocolate intake resulted in differential microbiota profiles and function (P < .05). Heat map of wrist temperature and sleep records showed that EC induced more regular timing of sleep episodes with lower variability of sleep onset among days than MC (60 min vs 78 min; P = .028). In conclusion, having chocolate in the morning or in the evening/night results in differential effects on hunger and appetite, substrate oxidation, fasting glucose, microbiota (composition and function), and sleep and temperature rhythms. Results highlight that the "when" we eat is a relevant factor to consider in energy balance and metabolism.

Molecular Determinants of the Cardiometabolic Improvements of Dietary Flavanols Identified by an Integrative Analysis of Nutrigenomic Data from a Systematic Review of Animal Studies

SCOPE

Flavanols are important polyphenols of the human diet with extensive demonstrations of their beneficial effects on cardiometabolic health. They contribute to preserve health acting on a large range of cellular processes. The underlying mechanisms of action of flavanols are not fully understood but involve a nutrigenomic regulation.

METHODS AND RESULTS

To further capture how the intake of dietary flavanols results in the modulation of gene expression, nutrigenomics data in response to dietary flavanols obtained from animal models of cardiometabolic diseases have been collected and submitted to a bioinformatics analysis. This systematic analysis shows that dietary flavanols modulate a large range of genes mainly involved in endocrine function, fatty acid metabolism, and inflammation. Several regulators of the gene expression have been predicted and include transcription factors, miRNAs and epigenetic factors.

CONCLUSION

This review highlights the complex and multilevel action of dietary flavanols contributing to their strong potential to preserve cardiometabolic health. The identification of the potential molecular mediators and of the flavanol metabolites driving the nutrigenomic response in the target organs is still a pending question which the answer will contribute to optimize the beneficial health effects of dietary bioactives.

The effect of cocoa/dark chocolate consumption on lipid profile, glycemia, and blood pressure in diabetic patients: A meta-analysis of observational studies

Due to the increasing rate of cardiovascular disease and related risk factors in the worldin recent decades, the present meta-analysis was performed to investigate the effects ofcocoa/chocolate consumption on lipid profile, glycemia, and blood pressure control in diabetic patients. A systematic search of the databases PubMed, Scopus, Web of Science, and Cochran Library was performed up to July 2020. All randomized controlled trials (RCTs) using cocoa/dark chocolate in diabetic patients were included in the study. The search results were limited to English-language publications. Eight RCTs, including 433 participants, were selected for this meta-analysis. Pooled analysis indicated a significant reduction in low-density lipoprotein cholesterol LDL-c levels (WMD: -15.49 mg/dl; 95% CI: -24.56, -6.42, p = .001) and fasting blood sugar (FBS) concentrations (WMD: -6.88 mg/dl; 95% CI: -13.28, -0.48, p = .03) following cocoa/dark chocolate consumption. The analysis of papers included in current study indicates that the consumption of cocoa/dark chocolate reduced the serum fasting blood glucose (FBS) and LDL cholesterol concentrations. However, further high quality trials are essential for confirming the clinical efficacy of cocoa/dark chocolate consumption on complete metabolic profile.

Beneficial effects of a combination of natural product activators of autophagy on endothelial cells and platelets

BACKGROUND AND PURPOSE

Oxidative stress and insufficient autophagy activity are associated with inflammatory processes and are common features of many cardiovascular diseases (CVDs). We investigated if a combination of natural activators of autophagy could modulate oxidative stress, platelet aggregation and endothelial cell survival and function in response to stress.

EXPERIMENTAL APPROACH

Ex vivo platelet aggregation and activation, H2 O2 production and autophagy were measured in platelets of subjects at high cardiovascular risk, including smokers, patients with metabolic syndrome (MetS) and patients with atrial fibrillation (AF). In vitro, the effects of a mixture of natural pro-autophagy molecules and antioxidants on platelets and human umbilical vein endothelial cells (HUVECs) were evaluated.

KEY RESULT

Autophagy appeared to be inhibited, whereas aggregation was increased in platelets from AF and MetS patients and in smokers, as compared with healthy subjects. Treatment of platelets isolated from these patients with a mixture composed of trehalose, spermidine, catechin and epicatechin (Mix1) or with a mixture composed of trehalose, spermidine and nicotinamide (Mix2), significantly reduced platelet activation and oxidative stress, and increased autophagy, compared with the effect of each compound alone. Similarly, treatment of HUVECs with a combination of these compounds exhibited beneficial effects and increased endothelial cell survival, nitric oxide bioavailability and angiogenesis in response to stress in a potentiated manner.

CONCLUSION AND IMPLICATIONS

A combination of natural activators of autophagy could inhibit platelet activity and oxidative stress and improve endothelial cell survival and function in a potentiated manner representing a useful strategy to reduce the effect of risk factors on CVD occurrence.

LINKED ARTICLES

This article is part of a themed issue on Cellular metabolism and diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.10/issuetoc.

Impact of Dietary Flavanols on Microbiota, Immunity and Inflammation in Metabolic Diseases

Flavanols are natural occurring polyphenols abundant in fruits and vegetables to which have been attributed to beneficial effects on health, and also against metabolic diseases, such as diabetes, obesity and metabolic syndrome. These positive properties have been associated to the modulation of different molecular pathways, and importantly, to the regulation of immunological reactions (pro-inflammatory cytokines, chemokines, adhesion molecules, nuclear factor-κB [NF-κB], inducible enzymes), and the activity of cells of the immune system. In addition, flavanols can modulate the composition and function of gut microbiome in a prebiotic-like manner, resulting in the positive regulation of metabolic pathways and immune responses, and reduction of low-grade chronic inflammation. Moreover, the biotransformation of flavanols by gut bacteria increases their bioavailability generating a number of metabolites with potential to affect human metabolism, including during metabolic diseases. However, the exact mechanisms by which flavanols act on the microbiota and immune system to influence health and disease remain unclear, especially in humans where these connections have been scarcely explored. This review seeks to summarize recent advances on the complex interaction of flavanols with gut microbiota, immunity and inflammation focus on metabolic diseases.

Regulation of Enteric Infection and Immunity by Dietary Proanthocyanidins

The role of dietary components in immune function has acquired considerable attention in recent years. An important focus area is to unravel the role of bioactive dietary compounds in relation to enteric disease and their impact on gut mucosal immunity. Proanthocyanidins (PAC) are among the most common and most consumed dietary polyphenols, and are characterised by their variable molecular structures and diverse bioactivities. In particular, their anti-oxidative effects and ability to modulate gut microbiota have been widely described. However, there is limited evidence on the mechanism of action of PAC on the immune system, nor is it clearly established how PAC may influence susceptibility to enteric infections. Establishing the sites of action of PAC and their metabolites within the gut environment is fundamental to determine the applicability of PAC against enteric pathogens. Some mechanistic studies have shown that PAC have direct modulatory effects on immune cell signalling, isolated pathogens, and gut mucosal barrier integrity. Boosting the recruitment of immune cells and suppressing the amount of pro-inflammatory cytokines are modulating factors regulated by PAC, and can either be beneficial or detrimental in the course of re-establishing gut homeostasis. Herein, we review how PAC may alter distinct immune responses towards enteric bacterial, viral and parasitic infections, and how the modulation of gut microbiota may act as a mediating factor. Furthermore, we discuss how future studies could help unravel the role of PAC in preventing and/or alleviating intestinal inflammation and dysbiosis caused by enteric disease.

Food Processing, Dysbiosis, Gastrointestinal Inflammatory Diseases, and Antiangiogenic Functional Foods or Beverages

Foods and beverages provide nutrients and alter the gut microbiota, resulting in eubiosis or dysbiosis. Chronic consumption of a diet that is high in saturated or trans fats, meat proteins, reducing sugars, and salt and low in fiber induces dysbiosis. Dysbiosis, loss of redox homeostasis, mast cells, hypoxia, angiogenesis, the kynurenine pathway, transglutaminase 2, and/or the Janus kinase pathway are implicated in the pathogenesis and development of inflammatory bowel disease, celiac disease, and gastrointestinal malignancy. This review discusses the effects of oxidative, carbonyl, or glycative stress-inducing dietary ingredients or food processing-derived compounds on gut microbiota and gastrointestinal epithelial and mast cells as well as on the development of associated angiogenic diseases, including key signaling pathways. The preventive or therapeutic potential and the biochemical pathways of antiangiogenic or proangiogenic foods or beverages are also described. The outcomes of the interactions between disease pathways and components of food are critical for the design of foods and beverages for healthy lives.

Pharmacological Effects and Potential Clinical Usefulness of Polyphenols in Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is arguably the most common benign disease among men. This disease is often associated with lower urinary tract symptoms (LUTS) in men and significantly decreases the quality of life. Polyphenol consumption reportedly plays an important role in the prevention of many diseases, including BPH. In recent years, in addition to disease prevention, many studies have reported the efficacy and safety of polyphenol treatment against various pathological conditions in vivo and in vitro. Furthermore, numerous studies have also revealed the molecular mechanisms of the antioxidant and anti-inflammatory effects of polyphenols. We believe that an improved understanding of the detailed pharmacological roles of polyphenol-induced activities at a molecular level is important for the prevention and treatment of BPH. Polyphenols are composed of many members, and their biological roles differ. In this review, we first provide information regarding the pathological roles of oxidative stress and inflammation in BPH. Next, the antioxidant and anti-inflammatory effects of polyphenols, including those of flavonoids and non-flavonoids, are discussed. Finally, we talk about the results and limitations of previous clinical trials that have used polyphenols in BPH, with particular focus on their molecular mechanisms of action.

(-)-Epicatechin and the comorbidities of obesity

Obesity has major adverse consequences on human health contributing to the development of, among others, insulin resistance and type 2 diabetes, cardiovascular disease, non-alcoholic fatty liver disease, altered behavior and cognition, and cancer. Changes in dietary habits and lifestyle could contribute to mitigate the development and/or progression of these pathologies. This review will discuss current evidence on the beneficial actions of the flavan-3-ol (-)-epicatechin (EC) on obesity-associated comorbidities. These benefits can be in part explained through EC's capacity to mitigate several common events underlying the development of these pathologies, including: i) high circulating levels of glucose, lipids and endotoxins; ii) chronic systemic inflammation; iii) tissue endoplasmic reticulum and oxidative stress; iv) insulin resistance; v) mitochondria dysfunction and vi) dysbiosis. The currently known underlying mechanisms and cellular targets of EC's beneficial effects are discussed. While, there is limited evidence from human studies supplementing with pure EC, other studies involving cocoa supplementation in humans, pure EC in rodents and in vitro studies, support a potential beneficial action of EC on obesity-associated comorbidities. This evidence also stresses the need of further research in the field, which would contribute to the development of human dietary strategies to mitigate the adverse consequences of obesity.

Antidiabetic Effects of Flavan-3-ols and Their Microbial Metabolites

Diet is one of the pillars in the prevention and management of diabetes mellitus. Particularly, eating patterns characterized by a high consumption of foods such as fruits or vegetables and beverages such as coffee and tea could influence the development and progression of type 2 diabetes. Flavonoids, whose intake has been inversely associated with numerous negative health outcomes in the last few years, are a common constituent of these food items. Therefore, they could contribute to the observed positive effects of certain dietary habits in individuals with type 2 diabetes. Of all the different flavonoid subclasses, flavan-3-ols are consumed the most in the European region. However, a large proportion of the ingested flavan-3-ols is not absorbed. Therefore, the flavan-3-ols enter the large intestine where they become available to the colonic bacteria and are metabolized by the microbiota. For this reason, in addition to the parent compounds, the colonic metabolites of flavan-3-ols could take part in the prevention and management of diabetes. The aim of this review is to present the available literature on the effect of both the parent flavan-3-ol compounds found in different food sources as well as the specific microbial metabolites of diabetes in order to better understand their potential role in the prevention and treatment of the disease.

Deciphering the Role of Polyphenols in Sports Performance: From Nutritional Genomics to the Gut Microbiota toward Phytonutritional Epigenomics

The individual response to nutrients and non-nutrient molecules can be largely affected by three important biological layers. The gut microbiome can alter the bioavailability of nutrients and other substances, the genome can influence molecule kinetics and dynamics, while the epigenome can modulate or amplify the properties of the genome. Today the use of omic techniques and bioinformatics, allow the construction of individual multilayer networks and thus the identification of personalized strategies that have recently been considered in all medical fields, including sports medicine. The composition of each athlete’s microbiome influences sports performance both directly by acting on energy metabolism and indirectly through the modulation of nutrient or non-nutrient molecule availability that ultimately affects the individual epigenome and the genome. Among non-nutrient molecules polyphenols can potentiate physical performances through different epigenetic mechanisms. Polyphenols interact with the gut microbiota, undergoing extensive metabolism to produce bioactive molecules, which act on transcription factors involved in mitochondrial biogenesis, antioxidant systems, glucose and lipid homeostasis, and DNA repair. This review focuses on polyphenols effects in sports performance considering the individual microbiota, epigenomic asset, and the genomic characteristics of athletes to understand how their supplementation could potentially help to modulate muscle inflammation and improve recovery.

A Critical Review on the Role of Food and Nutrition in the Energy Balance

The mass media has increasingly frequently suggested to the general population that specific foods or nutritional schemes are able to affect both human metabolism and energy expenditure, thus facilitating weight loss. This critical review is aimed at assessing available evidence on the roles of nutrients, food and dietary regimens in energy intake and energy expenditure. We queried the National Library of Medicine, the Cochrane Library, Excerpta Medica dataBASEand the Cumulative Index to Nursing and Allied Health Literature database, and a search strategy was performed by using database-specific subject headings and keywords. We found that available scientific evidence on these topics is scarce, and that the limited number of available studies often have poor methodological quality. Only a few foods show beneficial effects on metabolism and energy expenditure, as the human energy balance is complex and multifactorial. Finally, microbiota may interfere with the intake, use and expenditure of energy in the human body. Conclusive evidence is still lacking, and, at present, it is not possible to identify a food or a diet with a significant impact on human energy expenditure.

Effects of Raw and Roasted Cocoa Bean Extracts Supplementation on Intestinal Enzyme Activity, Biochemical Parameters, and Antioxidant Status in Rats Fed a High-Fat Diet

The aim of the study was to analyze the influence of diet containing the polyphenol-rich material on intestinal enzyme activity, oxidative stress markers, lipid metabolism and antioxidant status of laboratory rats. The animals were fed high-fat diet supplemented with freeze-dried water extracts of raw and roasted cocoa beans of Forastero variety. The observed changes indicated the biological activity of polyphenols and other components of the prepared cocoa beans extracts (CBEs). The presence of raw and roasted CBEs in the diets diversified the activity of the enzymes of the cecal microflora of rats. Both CBEs beneficially affect the antioxidant status of the serum, even in relation to the control standard group. The experimental cocoa bean preparations showed no significant effect on the mass of rats' liver, heart, and kidneys, but varied some parameters of the antioxidant status of their organisms. The raw CBE in rats fed with the high-fat diet shows a high ability to inhibit lipid peroxidation in heart and more effectively increases hepatic reduced glutathione (GSH) concentrations compared to the roasted CBE, which did not show any significant effect. Moreover, supplementation with both CBEs significantly affects the volatile fatty acids concentration in the rats' cecum. Results of this study contribute to the evidence that dietary supplementation with raw and roasted CBEs can exert health-promoting effects, however further studies are necessary.

Cacao extract enriched in polyphenols prevents endocrine-metabolic disturbances in a rat model of prediabetes triggered by a sucrose rich diet

ETHNOPHARMACOLOGICAL RELEVANCE

Cocoa extracts rich in polyphenols are used as potential agent for treating diabetes. Cocoa polyphenols have been proved to ameliorate important hallmarks of type-2 diabetes (T2D). They can regulate glucose levels by increasing insulin secretion, promoting β-cell proliferation and a reduction of insulin resistance. In addition, epidemiological evidence indicates that consumption of flavonoid decreases the incidence of T2D.

AIM OF THE STUDY

T2D is preceded by a prediabetic state in which the endocrine-metabolic changes described in T2D are already present. Since epidemiological evidence indicates that consumption of flavonoid decreases its incidence, we evaluated possible preventive effects of polyphenol-enriched cocoa extract on a model of prediabetes induced by sucrose.

MATERIALS AND METHODS

We determined circulating parameters and insulin sensitivity indexes, liver protein carbonyl groups and reduced glutathione, liver mRNA expression levels of lipogenic enzymes, expression of different pro-inflammatory mediators, fructokinase activity and liver glycogen content. For that, radioimmunoassay, real-time polymerase chain reaction, Western blot, spectrophotometry, and immunohistochemistry were used.

RESULTS

We demonstrated that sucrose administration triggered hypertriglyceridemia, insulin-resistance, and liver increased oxidative stress and inflammation markers compared to control rats. Additionally, we found an increase in glycogen deposit, fructokinase activity, and lipogenic genes expression (SREBP-1c, FAS and GPAT) together with a decrease in P-Akt and P-eNOS protein content (P < 0.05). Sucrose-induced insulin resistance, hepatic carbohydrate and lipid dysmetabolism, oxidative stress, and inflammation were effectively disrupted by polyphenol-enriched cocoa extract (PECE) co-administration (P < 0.05).

CONCLUSION

Dietary administration of cocoa flavanols may be an effective and complementary tool for preventing or reverting T2D at an early stage of its development (prediabetes).

Nutritionally Attenuating the Human Gut Microbiome To Prevent and Manage Metabolic Syndrome

Metabolic syndrome (MSyn) constitutes a litany of pathophysiological conditions, such as central adiposity, hypertension, dyslipidemia, and hyperglycemia. As a result of the epidemic levels of MSyn, several efforts have been made to identify the etiologies of the condition and develop methods by which to reduce its prevalence. The attenuation of the gut microflora ratio of Firmicutes/Bacteroidetes through bioactive compounds found in the Mediterranean diet, dietary polysaccharides, and pre- and probiotics can be used as functional foods to improve derangements in cardiometabolic markers correlated with the development of MSyn. Although more studies are needed to understand the role of manipulating the gut microbiota in health and disease in human models, this review based on current data from epidemiologic studies and clinical trials will serve as a review to elucidate the role nutrition plays in attenuating the gut microbiota in preventing and managing MSyn.

Dietary intakes of flavan-3-ols and cardiometabolic health: systematic review and meta-analysis of randomized trials and prospective cohort studies

BACKGROUND

Although available data suggest that some dietary flavan-3-ol sources reduce cardiometabolic risk, to our knowledge no review has systematically synthesized their specific contribution.

OBJECTIVE

We aimed to examine, for the first time, if there is consistent evidence that higher flavan-3-ol intake, irrespective of dietary source, reduces cardiometabolic risk.

METHODS

MEDLINE, Cochrane Central, and Commonwealth Agricultural Bureau abstracts were searched for prospective cohorts and randomized controlled trials (RCTs) published from 1946 to March 2019 on flavan-3-ol intake and cardiovascular disease (CVD) risk. Random-effects models meta-analysis was used. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach assessed the strength of evidence.

RESULTS

Of 15 prospective cohorts (23 publications), 4 found highest compared with lowest habitual intakes of flavan-3-ols were associated with a 13% reduction in risk of CVD mortality and 2 found a 19% reduction in risk of chronic heart disease (CHD) incidence. Highest compared with lowest habitual intakes of monomers were associated with a reduction in risk of type 2 diabetes mellitus (T2DM) (n = 5) and stroke (n = 4) (10% and 18%, respectively). No association was found for hypertension. Of 156 RCTs, flavan-3-ol intervention resulted in significant improvements in acute/chronic flow-mediated dilation (FMD), systolic (SBP) and diastolic blood pressure (DBP), total cholesterol (TC), LDL and HDL cholesterol, triglycerides (TGs), hemoglobin A1c (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR). All analyses, except HbA1c, were associated with moderate/high heterogeneity. When analyses were limited to good methodological quality studies, improvements in TC, HDL cholesterol, SBP, DBP, HOMA-IR, and acute/chronic FMD remained significant. In GRADE evaluations, there was moderate evidence in cohort studies that flavan-3-ol and monomer intakes were associated with reduced risk of CVD mortality, CHD, stroke, and T2DM, whereas RCTs reported improved TC, HDL cholesterol, SBP, and HOMA-IR.

CONCLUSIONS

Available evidence supports a beneficial effect of flavan-3-ol intake on cardiometabolic outcomes, but there was considerable heterogeneity in the meta-analysis. Future research should focus on an integrated intake/biomarker approach in cohorts and high-quality dose-response RCTs. This review was registered at www.crd.york.ac.uk/PROSPERO/ as CRD42018035782.

The Non-Covalent Interactions and In Vitro Radical Scavenging Activities of the Caseinate-Galangin and Caseinate-Genistein Complexes

Non-covalent interactions and in vitro radical scavenging activities of the complexes formed by the commercial milk protein product caseinate and one of the two polyphenols (galangin and genistein) were assessed by the multi-spectroscopic techniques, molecular docking, and detection of scavenging activities against the 1,1–diphenyl-2-picryl-hydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydroxyl radicals. The caseinate bound with the two polyphenols showed conformational changes and increased scavenging activities, compared with original caseinate. The caseinate-polyphenol binding was driven by the hydrophobic interaction and hydrogen-bonds, while hydrophobic interaction was the main binding force. Meanwhile, sodium dodecyl sulfate and urea could damage the essential hydrophobic interaction and hydrogen-bonds, respectively, and thus led to decreased apparent binding constants for the caseinate-polyphenol binding. Based on the measured values of several apparent thermodynamic parameters like ΔH, ΔS, ΔG, and donor–acceptor distance as well as the detected radical scavenging activity, galangin having more planar stereochemical structure and random B-ring rotation always had higher affinity for caseinate than genistein having location isomerism and twisted stereochemical structure, while the caseinate-galangin complex showed higher radical scavenging activity than the caseinate-genistein complex. It is thus concluded that both chemical and stereochemical structures of polyphenols are crucial to the affinity of polyphenols for protein and antioxidant activities of the protein-polyphenol complexes.

Depicting the Non-Covalent Interaction of Whey Proteins with Galangin or Genistein Using the Multi-Spectroscopic Techniques and Molecular Docking

The non-covalent interactions between a commercial whey protein isolate (WPI) and two bioactive polyphenols galangin and genistein were studied at pH 6.8 via the multi-spectroscopic assays and molecular docking. When forming these WPI-polyphenol complexes, whey proteins had changed secondary structures while hydrophobic interaction was the major driving force. Detergent sodium dodecyl sulfate destroyed the hydrophobic interaction and thus decreased apparent binding constants of the WPI-polyphenol interactions. Urea led to hydrogen-bonds breakage and protein unfolding, and therefore increased apparent binding constants. Based on the measured apparent thermodynamic parameters like ΔH, ΔS, ΔG, and donor-acceptor distance, galangin with more planar stereochemical structure and random B-ring rotation showed higher affinity for WPI than genistein with location isomerism and twisted stereochemical structure. The molecular docking results disclosed that β-lactoglobulin of higher average hydrophobicity had better affinity for the two polyphenols than α-lactalbumin of lower average hydrophobicity while β-lactoglobulin possessed very similar binding sites to the two polyphenols. It is concluded that polyphenols might have different non-covalent interactions with food proteins, depending on the crucial polyphenol structures and protein hydrophobicity.

Low doses of cocoa extract supplementation ameliorate diet-induced obesity and insulin resistance in rats

Cocoa polyphenols exhibit high antioxidant activity and have been proposed as a potential adjuvant for the treatment of metabolic disturbances. Here, we demonstrate that supplementation with low doses (14 and 140 mg per kg per rat) of a complete cocoa extract induces metabolic benefits in a diet-induced obesity (DIO) model of Wistar rats. After 10 weeks, cocoa extract-supplemented animals exhibited significantly lower body weight gain and food efficiency, with no differences in energy intake. Cocoa significantly reduced visceral (epididymal and retroperitoneal) and subcutaneous fat accumulation accompanied by a significant reduction in the adipocyte size, which was mediated by downregulation of the adipocyte-specific genes Cebpa, Fasn and Adipoq. Additionally, cocoa extract supplementation reduced the triacylglycerol/high density lipoprotein (TAG/HDL) ratio, decreased hepatic triglyceride accumulation, improved insulin sensitivity by reducing HOMA-IR, and significantly ameliorated glucose tolerance after an intraperitoneal glucose tolerance test. Finally, no adverse effect was observed in an in vivo toxicity evaluation of our cocoa extract at doses up to 500 mg kg^-1 day^-1. Our data demonstrate that low doses of cocoa extract supplementation (14 and 140 mg kg^-1 day^-1) are safe and sufficient to counteract obesity and type-2 diabetes in rats and provide new insights into the potential application of cocoa supplements in the management of the metabolic syndrome.

Role of Theobromine in Cocoa's Metabolic Properties in Healthy Rats

Cocoa is rich in polyphenols and methylxanthines, and it has been reported that its consumption, among other properties, has beneficial effects on metabolism. This study aimed to investigate the role of theobromine in cocoa's metabolic properties in healthy rats. In addition to morphometric measurements, biochemical markers of lipids and glucose metabolism and gene expression of molecules related to immune cells in adipose and hepatic tissues were assessed after 7 or 18 days of diet. Additionally, a metabolomic analysis was carried out at day 7. This study revealed the presence of six discriminant metabolites in plasma due to the diets. Moreover, the results showed that theobromine is the main responsible factor for cocoa's effects on body weight gain as well as on lipid and glucose metabolism. The effects on body weight and lipids appeared as early as after 7 days of diet, whereas those affecting glucose metabolism required a longer intervention.

Cocoa Flavanols: Natural Agents with Attenuating Effects on Metabolic Syndrome Risk Factors

The interest in cacao flavanols is still growing, as bioactive compounds with potential benefits in the prevention of chronic diseases associated with inflammation, oxidative stress and metabolic disorders. Several analytical methodologies support that the flavanols in cacao-derived products can be absorbed, have bioactive properties, and thus can be responsible for their beneficial effects on human health. However, it must be considered that their biological actions and underlying molecular mechanisms will depend on the concentrations achieved in their target tissues. Based on the antioxidant properties of cacao flavanols, this review focuses on recent advances in research regarding their potential to improve metabolic syndrome risk factors. Additionally, it has included other secondary plant metabolites that have been investigated for their protective effects against metabolic syndrome. Studies using laboratory animals or human subjects represent strong available evidence for biological effects of cacao flavanols. Nevertheless, in vitro studies are also included to provide an overview of these phytochemical mechanisms of action. Further studies are needed to determine if the main cacao flavanols or their metabolites are responsible for the observed health benefits and which are their precise molecular mechanisms.

Effect of cocoa on the brain and gut in healthy subjects: a randomised controlled trial

Dark chocolate is claimed to have effects on gastrointestinal function and to improve well-being. This randomised controlled study tested the hypothesis that cocoa slows gastric emptying and intestinal transit. Functional brain imaging identified central effects of cocoa on cortical activity. Healthy volunteers (HV) ingested 100 g dark (72 % cocoa) or white (0 % cocoa) chocolate for 5 d, in randomised order. Participants recorded abdominal symptoms and stool consistency by the Bristol Stool Score (BSS). Gastric emptying (GE) and intestinal and colonic transit time were assessed by scintigraphy and marker studies, respectively. Combined positron emission tomography-computed tomography (PET-CT) imaging assessed regional brain activity. A total of sixteen HV (seven females and nine males) completed the studies (mean age 34 (21-58) years, BMI 22·8 (18·5-26·0) kg/m2). Dark chocolate had no effect on upper gastrointestinal function (GE half-time 82 (75-120) v. 83 (60-120) min; P=0·937); however, stool consistency was increased (BSS 3 (3-5) v. 4 (4-6); P=0·011) and there was a trend to slower colonic transit (17 (13-26) v. 21 (15-47) h; P=0·075). PET-CT imaging showed increased [18F]fluorodeoxyglucose (FDG) in the visual cortex, with increased FDG uptake also in somatosensory, motor and pre-frontal cortices (P<0·001). In conclusion, dark chocolate with a high cocoa content has effects on colonic and cerebral function in HV. Future research will assess its effects in patients with functional gastrointestinal diseases with disturbed bowel function and psychological complaints.

Impact of a Usual Serving Size of Flavanol-Rich Cocoa Powder Ingested with a Diabetic-Suitable Meal on Postprandial Cardiometabolic Parameters in Type 2 Diabetics-A Randomized, Placebo-Controlled, Double-Blind Crossover Study

Randomized controlled trials indicate that flavanol-rich cocoa intake may improve postprandial glucose and lipid metabolism in patients with type 2 diabetes (T2D), based on studies with meals that impose a strong metabolic load. Hence, the aim of the present study was to investigate whether flavanol-rich cocoa powder ingested as part of a diabetic-suitable meal may beneficially affect glucose, lipid metabolism, and blood pressure (BP) in patients with T2D. Twelve adults with T2D, overweight/obesity, and hypertension ingested capsules with 2.5 g of flavanol-rich cocoa or microcrystalline cellulose with a diabetic-suitable breakfast in a randomized, placebo-controlled, double-blind crossover study. BP was measured and blood samples were taken before, 2 and 4 h after breakfast and capsule intake. Cocoa treatment did not affect glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), triglycerides, total cholesterol, low density lipoprotein-cholesterol, high density lipoprotein-cholesterol, and BP. For glucose, insulin and HOMA-IR, only effects by time were observed after both treatments. Thus, 2.5 g of flavanol-rich cocoa powder ingested as part of a diabetic-suitable meal does not seem to affect postprandial glucose and lipid metabolism and BP in stably-treated diabetics. Nevertheless, future studies with close-meshed investigations are desirable, providing realistic amounts of cocoa together with realistic meals rich in carbohydrates to subjects with T2D or metabolic syndrome, which do not afford pharmacological treatment.

Flavanols protect the yeast Saccharomyces cerevisiae against heating and freezing/thawing injury

AIMS

The aim of the study was to check whether two flavanols ((-)-epigallocatechin gallate and (+)-catechin) can ameliorate oxidative stress (OS) accompanying and contributing to the lethal effects of heating (50°C) and freezing-thawing on the yeast Saccharomyces cerevisiae.

METHODS AND RESULTS

The flavanols studied increased yeast survival during heating and freezing-thawing, estimated by the colony forming assay. They improved also such indices of OS as increased production of reactive oxygen species, decrease of total antioxidant activity of yeast cell extracts and increase in the level of protein carbonyls.

CONCLUSIONS

Amelioration of OS by flavanols increases the survival of the yeast subjected to high temperature and freezing-thawing.

SIGNIFICANCE AND IMPACT OF THE STUDY

Flavanols may be considered as means of enhancing yeast survival under extreme temperature conditions and probably in other conditions involving OS.

Potential role of phytochemicals in metabolic syndrome prevention and therapy

Metabolic syndrome (MetS) is a set of cardiovascular risk factors which severely increases the risk of type II diabetes, renal disease and cardiovascular disease. Over the last decades, the role of dietary bioactive substances in features of MetS has been extensively investigated. Due to their multiple properties, these plant-derived natural compounds have demonstrated to provide positive effects in obesity, diabetes, renal and in cardiovascular disease. Catechins of green tea and caffeine reduce body mass index and waist circumference. Catechins, anthocyanins and proanthocyanidins of cocoa reduce blood pressure and blood glucose. Curcumin and silymarin exert hepatoprotective effects. Monacolins of red yeast rice are effective cholesterol-lowering agents. However, inconsistent or conflicting results have been found in clinical trials when other promising compounds in vitro or in animal studies, such as policosanol, curcumin or silymarin, were used. Low oral bioavailability of substances, ineffective dosages, inadequate treatment duration and insufficient statistical approach may explain the lack of effectiveness observed in some human studies. Further clinical studies are needed to better understand the role of bioactive compounds in the prevention and management of MetS.

Cocoa Flavanol Supplementation and Exercise: A Systematic Review

BACKGROUND

Cocoa flavanols (CFs) have antioxidant and anti-inflammatory capacities and can improve vascular function. It has recently been suggested that CF intake may improve exercise performance and recovery. This systematic review aimed to evaluate the literature on the effects of CF intake on exercise performance and recovery and exercise-induced changes in vascular function, cognitive function, oxidative stress, inflammation, and metabolic parameters.

METHODS

Two electronic databases (Pubmed and Web of Science) were searched for studies examining the combination of CF intake and exercise in humans (up to 28 March 2017). Articles were included if the exact amount of CFs was mentioned. The methodological quality and level of bias of the 13 included studies was assessed according to the checklist for randomized controlled trials from the Dutch Cochrane center.

RESULTS

Acute, sub-chronic (2 weeks) and chronic (3 months) CF intake reduced exercise-induced oxidative stress. Evidence on the effect of CF on exercise-induced inflammation and platelet activation was scarce. Acute CF intake reduced and tempered the exercise-induced increase in blood pressure in obese participants. Acute and sub-chronic CF intake altered fat and carbohydrate metabolism during exercise. Acute and sub-chronic CF intake did not have ergogenic effects in athletes, while chronic CF intake improved mitochondrial efficiency in untrained participants. While combining sub-chronic CF intake and exercise training improved cardiovascular risk factors and vascular function, evidence on the synergistic effects of CF and exercise training on oxidative stress, inflammation, and fat and glucose metabolism was lacking.

CONCLUSION

CF intake may improve vascular function, reduce exercise-induced oxidative stress, and alter fat and carbohydrate utilization during exercise, but without affecting exercise performance. There is a strong need for future studies examining the synergetic effect of chronic CF intake and exercise training.

Regular Intake of a Usual Serving Size of Flavanol-Rich Cocoa Powder Does Not Affect Cardiometabolic Parameters in Stably Treated Patients with Type 2 Diabetes and Hypertension-A Double-Blinded, Randomized, Placebo-Controlled Trial

Regular cocoa consumption has been shown to improve blood pressure (BP), insulin sensitivity, and lipid levels in patients with type 2 diabetes (T2D), using up to 100 g of chocolate or 54 g of cocoa. These effects, attributed to cocoa flavanols, would be beneficial for patients with T2D if they could be achieved by a usual serving size of flavanol-rich cocoa. Forty-two hypertensive patients with T2D (stable pharmacological treatment, with good adjustment for glucose metabolism, lipids, and BP) ingested capsules with 2.5 g/day of a flavanol-rich cocoa or cocoa-free capsules for 12 weeks in a double-blinded, randomized, placebo-controlled study with parallel group design. Participants had to maintain diet, lifestyle, and medication. Before and after intervention, fasting blood samples were collected; BP and nutritional status were investigated. Cocoa treatment did not affect BP, nor glucose metabolism (glucose, HbA_1c, insulin, HOMA-IR) and lipids (triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol). Body weight, fat mass, and nutrient supply remained unchanged. Changes in the placebo group did not occur. Regular intake of a usual serving size of flavanol-rich cocoa does not improve cardiometabolic parameters in stably treated patients with T2D and hypertension. As the medication modulates partly the same targets as cocoa flavanols, future studies should focus on the preventive effect of cocoa against diabetes and other cardiometabolic diseases in individuals with preexisting abnormalities that do not require any pharmacological treatment.

Bioactive Compounds and Extracts from Traditional Herbs and Their Potential Anti-Inflammatory Health Effects

The inflammatory processes associated with several chronic illnesses like cardiovascular disease and cancer have been the focus of mechanistic studies of the pathogenicity of these diseases and of the use of different pharmacological and natural methods to prevent them. In this study we review the current evidence regarding the effectiveness of natural extracts from as-yet little-studied traditional botanical species in alleviating the inflammation process associated with several chronic diseases. Additionally, the intention is to expose the known pathways of action and the potential synergistic effects of the constituent compounds of the discussed extracts. It is noted that the here-studied extracts, which include black garlic rich in S-allylcystein, polyphenols from cat’s claw (Uncaria tomentosa), devil’s claw (Harpagophytum procumbens), camu-camu (Myrciaria dubia), and blackcurrant (Ribes nigrum), and citrus fruit extracts rich in hesperidin, have similar or greater effects than other, more extensively studied extracts such as tea and cocoa. The combined use of all of these extracts can give rise to synergetic effects with greater biological relevance at lower doses.

Intake of cocoa products and risk of type-2 diabetes: the multiethnic cohort

BACKGROUND/OBJECTIVES

As cocoa products may be protective against chronic disease due to their polyphenol content, the current study determined the association of chocolate consumption and flavanol intake with type-2 diabetes (T2D) incidence in the Multiethnic Cohort (MEC) Study.

SUBJECTS/METHODS

The analysis included 151,691 participants of Native Hawaiian, Japanese American, Latino, African American, and white ancestry with 8487 incident T2D cases after 7.8 ± 3.5 years of follow-up. T2D status was based on three self-reports and confirmed by at least one of three administrative data sources. Dietary intake was assessed using a validated quantitative food frequency questionnaire, and flavanols from cocoa products were estimated from self-reported consumption of chocolate candy and drinks. Cox hazard regression, adjusted for potential confounders was applied to estimate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

For chocolate candy, both the highest vs. lowest (≥10 vs. <1 g/day) consumption (HR = 0.90; 95% CI, 0.83-0.97; p_trend = 0.01) and the frequency (≥4/week vs. <1/month) of intake (HR = 0.81; 95% CI, 0.72-0.91; p_trend = 0.0002) were inversely associated with T2D. The estimated flavanol intake from cocoa products (≥3 vs. <1 mg/day) also showed an inverse association with T2D risk (HR = 0.93; 95% CI, 0.88-0.99; p_trend = 0.02). Significant interaction terms indicated that the inverse relation was limited to Japanese Americans, normal-weight individuals, and to those without comorbidities.

CONCLUSIONS

The current study confirms previous reports that participants with high intake of chocolate products and cocoa-derived flavanols experience a reduced risk of developing T2D even after controlling for sugar intake, diet quality, and other aspects of the diet.

Epicatechin's cardiovascular protective effects are mediated via opioid receptors and nitric oxide

PURPOSE

Cardiovascular disease is the leading cause of mortality globally. Epicatechin has previously been shown to improve vascular responses and possess cardioprotective properties. However, the mechanisms underpinning these cardiotropic outcomes remain unknown. The aim of this study was to further identify epicatechin's mechanism of action in the cardiovasculature.

METHODS

The effects of epicatechin on isolated rat conduit arteries, resistance vessels and cardiac electrophysiology were investigated on resting tension and precontracted vessels and cardiac action potential parameters, both in the presence and in the absence of various antagonists.

RESULTS

At resting tension, epicatechin alone did not affect the vasoreactivity of either conduit or resistance vessels. In noradrenaline pre-contracted thoracic aortic arteries and potassium chloride pre-contracted mesenteric vessels, epicatechin (10^-9-10^-4 M) induced significant vasorelaxation. The addition of naloxone (10^-5 M), N^G-nitro-L-arginine methyl ester (10^-5M), 4-aminopyridine (5 mM) and verapamil (10^-5 M) attenuated epicatechin-mediated vasorelaxation. No change in epicatechin-mediated vasorelaxation was observed with the addition of atropine (10^-5 M). Epicatechin significantly improved cardiac electrophysiology by reducing the resting membrane potential, action potential amplitude and force of contraction that was mitigated following the addition of naloxone (10^-5 M). Epicatechin significantly decreased the action potential duration at 20, 50 and 90% duration and time to 90% relaxation of force that was unchanged following the addition of naloxone (10^-5 M).

CONCLUSIONS

These findings suggest epicatechin's vascular responses and cardioprotective effects are mediated through opioid receptors, nitric oxide, potassium channel and calcium channel activation and highlight the importance of the endothelium/nitric oxide in epicatechin mediated vasorelaxation.