Effect of dark chocolate on flow-mediated dilatation: Systematic review, meta-analysis, and dose–response analysis of randomized controlled trials

Effects of pre-exercise intake of plant- and animal-based foods on arterial function and aerobic exercise capacity in healthy young men: a randomized cross-over trial

The purpose of this study was to examine the effects of plant- versus animal-based food intake before exercise on arterial function and subsequent aerobic exercise capacity. Eleven healthy adult males (mean age, 22.6 ± 1.8 years) participated in this study. A plant- or animal-based randomized meal type crossover comparison was conducted on separate days with a uniform protein, fat, and carbohydrate balance. Both carotid-femoral pulse wave velocity (cfPWV), femoral-ankle pulse wave velocity (faPWV), and brachial artery flow-mediated dilatation (FMD) were measured as indexes of aortic and peripheral arterial stiffness and vascular endothelial function, respectively, before and at 120 min after the meal. After these measurements, maximal oxygen uptake was assessed using a graded power test on an electronically braked cycle ergometer. The results revealed that cfPWV was significantly lower, whereas FMD was significantly higher, at 120 min after compared with before the plant-based meal (p = 0.01 and 0.02, respectively). By contrast, cfPWV and FMD did not change at 120 min after compared with before the animal-based meal. In addition, faPWV did not change at 120 min after compared with before the meal for either meal type. Maximal oxygen uptake was higher in the plant- than in the animal-based meal type (p = 0.02). These results suggest that pre-exercise plant-based food intake may improve central arterial stiffness and vascular endothelial function, which may have favorable implications for aerobic exercise capacity.

Sensory Nutrition and Bitterness and Astringency of Polyphenols

Recent studies have demonstrated that the interaction of dietary constituents with taste and olfactory receptors and nociceptors expressed in the oral cavity, nasal cavity and gastrointestinal tract regulate homeostasis through activation of the neuroendocrine system. Polyphenols, of which 8000 have been identified to date, represent the greatest diversity of secondary metabolites in plants, most of which are bitter and some of them astringent. Epidemiological studies have shown that polyphenol intake contributes to maintaining and improving cardiovascular, cognitive and sensory health. However, because polyphenols have very low bioavailability, the mechanisms of their beneficial effects are unknown. In this review, we focused on the taste of polyphenols from the perspective of sensory nutrition, summarized the results of previous studies on their relationship with bioregulation and discussed their future potential.

Endothelial dysfunction as a factor leading to arterial hypertension

Hypertension remains the main cause of cardiovascular complications leading to increased mortality. The discoveries of recent years underline the important role of endothelial dysfunction (ED) in initiating the development of arterial hypertension. The endothelium lines the interior of the entire vascular system in the body and acts as a physical barrier between blood and tissues. Substances and mediators produced by the endothelium exhibit antithrombotic and anti-inflammatory properties. Oxidative stress and inflammation are conditions that damage the endothelium and shift endothelial function from vasoprotective to vasoconstrictive, prothrombotic, and pro-apoptotic functions. A dysfunctional endothelium contributes to the development of hypertension and further cardiovascular complications. Reduced nitric oxide (NO) bioavailability plays an essential role in the pathophysiology of ED-associated hypertension. New technologies provide tools to identify pathological changes in the structure and function of the endothelium. Endothelial dysfunction (ED) contributes to the development of arterial hypertension and should be considered in therapeutic strategies for children with hypertension.

Chemical Characterization, Antioxidant Capacity and Anti-Oxidative Stress Potential of South American Fabaceae Desmodium tortuosum

It has been proposed that oxidative stress is a pathogenic mechanism to induce cytotoxicity and to cause cardiovascular and neuronal diseases. At present, natural compounds such as plant extracts have been used to reduce the cytotoxic effects produced by agents that induce oxidative stress. Our study aimed to evaluate the antioxidant and cytoprotective capacity of Desmodium tortuosum (D. tortuosum) extract in the co- and pre-treatment in EA.hy926 and SH-SY5Y cell lines subjected to oxidative stress induced by tert-butylhydroperoxide (t-BOOH). Cell viability, reactive oxygen species (ROS), nitric oxide (NO), caspase 3/7 activity, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), and molecular expression of oxidative stress biomarkers (SOD2, NRF2 and NFκB1) and cell death (APAF1, BAX, Caspase3) were all evaluated. It was observed that the D. tortuosum extract, in a dose-dependent manner, was able to reduce the oxidative and cytotoxicity effects induced by t-BOOH, even normalized to a dose of 200 µg/mL, which would be due to the high content of phenolic compounds mainly phenolic acids, flavonoids, carotenoids and other antioxidant compounds. Finally, these results are indicators that the extract of D. tortuosum could be a natural alternative against the cytotoxic exposure to stressful and cytotoxic chemical agents.

Dark chocolate (70% cocoa) attenuates the inflammatory marker TNF-α in patients on hemodialysis

BACKGROUND

Inflammation and oxidative stress lead to a high risk of cardiovascular disease in patients with chronic kidney disease (CKD). Food rich in polyphenols such as dark chocolate may be an effective strategy to mitigate inflammation and delay CKD complications, outwith sensorial pleasure promotion. The aim of this study was to evaluate the effects of dark chocolate on inflammation and oxidative stress markers in patients with CKD on hemodialysis (HD).

METHODS

A clinical trial was carried out with 59 patients who were allocated into the chocolate group [40g of dark chocolate (70% cocoa) offered during HD sessions, 3×/week] or the control group with any intervention for two months. Plasma levels of the inflammatory cytokines TNF-α and IL-6 were evaluated by the ELISA method. Thiobarbituric acid reactive substances such as malondialdehyde (MDA) and LDLox levels were evaluated as lipid peroxidation markers. Routine biochemical parameters were analysed using commercial BioClin® kits.

RESULTS

Thirty-five patients completed the chocolate group (18 men, 53.0 (16) years and 31.0 (39) months on HD) and 11 in the control group (7 men, 48.0 (17.5) years and 44.0 (56.5) months on HD). Regarding the differences between the groups, the patients who received dark chocolate had reduced plasma levels of TNF-α compared to the control (p = 0.008). No significant changes were observed in the oxidative stress parameters evaluated in both groups. Routine biochemical (including phosphorus and potassium levels) and anthropometric parameters and food intake were not changed after the study period.

CONCLUSION

The intervention with dark chocolate (70% cocoa) for two months reduced the plasma levels of TNF-α in patients with CKD on HD. In addition, it is essential to emphasise that chocolate intake did not increase the plasma levels of phosphorus and potassium in these patients. This study was registered at clinicaltrials.gov as NCT04600258.

From Cocoa to Chocolate: Effect of Processing on Flavanols and Methylxanthines and Their Mechanisms of Action

Despite the health benefits associated with the ingestion of the bioactive compounds in cocoa, the high concentrations of polyphenols and methylxanthines in the raw cocoa beans negatively influence the taste, confer the astringency and bitterness, and affect the stability and digestibility of the cocoa products. It is, therefore, necessary to process cocoa beans to develop the characteristic color, taste, and flavor, and reduce the astringency and bitterness, which are desirable in cocoa products. Processing, however, affects the composition and quantities of the bioactive compounds, resulting in the modification of the health-promoting properties of cocoa beans and chocolate. In this advanced review, we sought to better understand the effect of cocoa's transformational process into chocolate on polyphenols and methylxanthine and the mechanism of action of the original flavanols and methylxanthines. More data on the cocoa processing effect on cocoa bioactives are still needed for better understanding the effect of each processing step on the final polyphenolic and methylxanthine composition of chocolate and other cocoa products. Regarding the mechanisms of action, theobromine acts through the modulation of the fatty acid metabolism, mitochondrial function, and energy metabolism pathways, while flavanols mainly act though the protein kinases and antioxidant pathways. Both flavanols and theobromine seem to be involved in the nitric oxide and neurotrophin regulation.

Acute Effects of Cocoa Flavanols on Blood Pressure and Peripheral Vascular Reactivity in Type 2 Diabetes Mellitus and Essential Hypertension

Background: Type 2 diabetes mellitus (T2DM) is associated with a high risk of vascular complications. Interestingly, cocoa flavanols (CF) can exert beneficial vascular effects in non-diabetic subjects. However, these effects have only been scarcely studied in T2DM. Therefore, we performed a study to assess the effects on vascular reactivity of a single dose of CF (790 mg) in T2DM and whether certain antihypertensive drugs may modulate these effects. Methods: 24 non-diabetic and 11 T2DM subjects were studied in a cross-over design. Fasting blood samples, blood pressure (BP), and arterial vasoreactivity (flow-mediated dilation) were assessed before and 70 min after capsule ingestion. Muscle microvascular reactivity was only assessed after capsule ingestion. Age, waist-to-hip ratio, BP at baseline, and the use of antihypertensive drugs were regarded as covariates in a mixed models analysis. Results: CF ingestion did not affect any parameter. However, independent of the type of capsules ingested, a decrease in diastolic BP by 3 mmHg (95% CI: −4.0; −2.0) and an increase in the change in brachial artery diameter (pre vs. post occlusion) by 0.06 mm (95% CI: 0.01; 0.12) were detected in the non-diabetic group, while they remained unchanged in the T2DM group. Conclusion: No beneficial effects of CF were detected on vascular reactivity parameters in T2DM and non-diabetic participants.

Impact of cocoa flavanols on human health

Cocoa is a source of flavanols, and these phenolic compounds exert beneficial effects on health and aging, and reduce the risk of suffering chronic diseases (cardiovascular diseases, metabolic disorders, cancer). An increasing body of evidence has emerged to suggest that cocoa flavanols potentially are important chemopreventive natural agents. This review summarizes human studies from the past two decades, providing data related to the effects derived from cocoa intake on health and disease. Most human studies have reported beneficial effects of cocoa consumption on health and chronic diseases; however, outcomes are not unequivocal. Review of human studies enable to identify different mechanisms of action for cocoa, although they are not fully understood at present. In addition, it remains unclear whether cocoa consumption should be recommended to healthy subjects or to patients and what is the appropriate dosage or duration of cocoa consumption. Elucidation of information regarding these crucial issues could lead to cocoa use as an approach for decreasing the risk of certain chronic diseases, as well as improving health and quality of life.