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.

The effects of cocoa flavanols on indices of muscle recovery and exercise performance: a narrative review

Exercise-induced muscle damage (EIMD) is associated with oxidative stress and inflammation, muscle soreness, and reductions in muscle function. Cocoa flavanols (CF) are (poly)phenols with antioxidant and anti-inflammatory effects and thus may attenuate symptoms of EIMD. The purpose of this narrative review was to collate and evaluate the current literature investigating the effect of CF supplementation on markers of exercise-induced oxidative stress and inflammation, as well as changes in muscle function, perceived soreness, and exercise performance. Acute and sub-chronic intake of CF reduces oxidative stress resulting from exercise. Evidence for the effect of CF on exercise-induced inflammation is lacking and the impact on muscle function, perceived soreness and exercise performance is inconsistent across studies. Supplementation of CF may reduce exercise-induced oxidative stress, with potential for delaying fatigue, but more evidence is required for any definitive conclusions on the impact of CF on markers of EIMD. Graphic abstract

Evaluation of Poorly-Bioavailable Cocoa Flavanols and Their Gut Microbial Metabolites in Potentiating Anti-diabetic Activities Through BTBR.Cg-Lepob/ob/WiscJ Mice

Objectives Cocoa (Theobroma cacao) is a concentrated dietary source of flavanols that have beneficial activities against type-2 diabetes. These compounds have limited small intestinal absorption and are metabolized by the microbiota to bioavailable metabolites that may exert anti-diabetic effects locally and in peripheral tissues. Our objectives were to 1) determine the role of the gut microbiome in facilitating protective effects of cocoa flavanols, and 2) evaluate these effects in a novel mouse model of progressive type-2 diabetes. Methods A small pilot study (n = 3) of male and female BTBR mice (wild-type and homozygous for the Lepob mutation) received either control or cocoa extract-supplemented diet for 10 weeks. Half the animals were administered antibiotics orally to knock down the commensal gut microbiota. Glucose and insulin tolerance tests were conducted at weeks 1 and 5 and 2 and 6, respectively. Weight gain and food intake were monitored weekly. Biomarkers of gut integrity and inflammation were assessed by ELISA. Results Baseline fasting blood glucose (FBG) levels in five-week-old homozygous males and females were measured at 211–271 mg/dL and 112–234 mg/dL, respectively. After five weeks, FBG measured at 281–438 mg/dL and 177–562 mg/dL, respectively. Cocoa provided moderate, yet not significant, protection against weight gain in homozygous males when compared to homozygous males fed control diet. Cocoa provided no significant protection against hypoglycemia in homozygous male or female mice when compared to homozygous controls. In treatment comparisons with and without antibiotics, knocking out the commensal gut microbiota appeared to have minimal effect on weight gain and glycemic control in both males and females. Conclusions Cocoa did provide a moderate level of protection for homozygous males when directly comparing weight gain and FBG across sex. While the microbiome has displayed a promising role in the bioavailability of large flavanols, in this particular model, the impact was minimal. Overall, cocoa was ineffective against the mediation of advanced diabetes and further work must be conducted to understand if this conclusion is isolated to this model of progressive type-2 diabetes. Funding Sources This work was supported by the US Department of Agriculture by AFRI grant 2020–67,017-30,846.

Cocoa-flavanols enhance moderate-intensity pulmonary $$\dot{V}{\text{O}}_{2}$$ kinetics but not exercise tolerance in sedentary middle-aged adults

Introduction Cocoa flavanols (CF) may exert health benefits through their potent vasodilatory effects, which are perpetuated by elevations in nitric oxide (NO) bioavailability. These vasodilatory effects may contribute to improved delivery of blood and oxygen (O2) to exercising muscle. Purpose Therefore, the objective of this study was to examine how CF supplementation impacts pulmonary O2 uptake ($$\dot{V}{\text{O}}_{2}$$ V ˙ O 2 ) kinetics and exercise tolerance in sedentary middle-aged adults. Methods We employed a double-blind cross-over, placebo-controlled design whereby 17 participants (11 male, 6 female; mean ± SD, 45 ± 6 years) randomly received either 7 days of daily CF (400 mg) or placebo (PL) supplementation. On day 7, participants completed a series of ‘step’ moderate- and severe-intensity exercise tests for the determination of $$\dot{V}{\text{O}}_{2}$$ V ˙ O 2 kinetics. Results During moderate-intensity exercise, the time constant of the phase II $$\dot{V}{\text{O}}_{2}$$ V ˙ O 2 kinetics ($$\tau \dot{V}{\text{O}}_{2}$$ τ V ˙ O 2 ) was decreased by 15% in CF as compared to PL (mean ± SD; PL 40 ± 12 s vs. CF 34 ± 9 s, P = 0.019), with no differences in the amplitude of $$\dot{V}{\text{O}}_{2}$$ V ˙ O 2 (A$$\dot{V}{\text{O}}_{2}$$ V ˙ O 2 ; PL 0.77 ± 0.32 l min−1 vs. CF 0.79 ± 0.34 l min−1, P = 0.263). However, during severe-intensity exercise, $$\tau \dot{V}{\text{O}}_{2}$$ τ V ˙ O 2 , the amplitude of the slow component ($${\text{SC}}\dot{V}{\text{O}}_{2}$$ SC V ˙ O 2 ) and exercise tolerance (PL 435 ± 58 s vs. CF 424 ± 47 s, P = 0.480) were unchanged between conditions. Conclusion Our data show that acute CF supplementation enhanced $$\dot{V}{\text{O}}_{2}$$ V ˙ O 2 kinetics during moderate-, but not severe-intensity exercise in middle-aged participants. These novel effects of CFs, in this demographic, may contribute to improved tolerance of moderate-activity physical activities, which appear commonly present in daily life. Trial registration Registered under ClinicalTrials.gov Identifier no. NCT04370353, 30/04/20 retrospectively registered

Cocoa Flavanols Improve Vascular Responses to Acute Mental Stress in Young Healthy Adults

Mental stress has been shown to induce cardiovascular events, likely due to its negative impact on vascular function. Flavanols, plant-derived polyphenolic compounds, improve endothelial function and blood pressure (BP) in humans, however their effects during stress are not known. This study examined the effects of acute intake of cocoa flavanols on stress-induced changes on vascular function. In a randomised, controlled, double-blind, cross-over intervention study, 30 healthy men ingested a cocoa flavanol beverage (high-flavanol: 150 mg vs. low-flavanol < 4 mg (−)-epicatechin) 1.5 h before an 8-min mental stress task). Forearm blood flow (FBF), BP, and cardiovascular activity were assessed pre- and post-intervention, both at rest and during stress. Endothelial function (brachial flow-mediated dilatation, FMD) and brachial BP were measured before the intervention and 30 and 90 min post-stress. FMD was impaired 30 min post-stress, yet high-flavanol cocoa attenuated this decline and remained significantly higher compared to low-flavanol cocoa at 90 min post-stress. High-flavanol cocoa increased FBF at rest and during stress. Stress-induced cardiovascular and BP responses were similar in both conditions. Flavanols are effective at counteracting mental stress-induced endothelial dysfunction and improving peripheral blood flow during stress. These findings suggest the use of flavanol-rich dietary strategies to protect vascular health during stress.

Acute Effects of Cocoa Flavanols on Blood Pressure and Peripheral Vascular Reactivity in Type 2 Diabetes Mellitus and Essential Hypertension: A Protocol for an Acute, Randomized, Double-Blinded, Placebo-Controlled Cross-Over Trial

Introduction: Patients with type 2 diabetes mellitus are at high risk to develop vascular complications resulting in high morbidity and mortality. Cocoa flavanols are promising nutraceuticals with possible beneficial vascular effects in humans. However, limited research is currently available on the vascular effects in a diabetic population with inconsistent results. Possible reasons for this inconsistency might be heterogeneity in the given intervention (dose per time and day, single dose vs. split-dose, placebo formula) and the studied population (blood pressure at baseline, duration of diabetes, use of vasoactive antihypertensive and antidiabetic drugs, sex). Therefore, we aimed to develop a randomized, double-blinded, placebo-controlled cross-over trial to investigate whether cocoa flavanols have an acute impact on blood pressure and vascular reactivity in patients with type 2 diabetes with and without arterial hypertension.Methods and Analysis: We will include participants in four groups: (i) patients with type 2 diabetes without arterial hypertension, (ii) patients with type 2 diabetes with arterial hypertension and 1 antihypertensive drug, (iii) non-diabetic participants with essential hypertension and 1 antihypertensive drug, and (iv) healthy controls. All participants will complete the same protocol on both testing days, consuming high-flavanol cocoa extract (790 mg flavanols) or placebo. Macrovascular endothelial function (flow-mediated dilation) and blood pressure will be measured before and after capsule ingestion. Forearm muscle vasoreactivity (near-infrared spectroscopy) and brachial artery blood flow (echo-doppler) will be assessed in response to a dynamic handgrip exercise test after capsule ingestion. Data will be analyzed with a random intercept model in mixed models.Clinical Trial Registration:www.Clinicaltrials.gov, identifier: NCT03722199.