Effects of cocoa powder and dark chocolate on LDL oxidative susceptibility and prostaglandin concentrations in humans. Regular dark chocolate consumption's reduction of oxidative stress and increase of free-fatty-acid mobilization in response to prolonged cycling. Cocoa Reduces Blood Pressure and Insulin Resistance and Improves Endothelium-Dependent Vasodilation in Hypertensives A double-blind, placebo-controlled, randomized trial of the effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health: clinical findings from a sample of healthy, cognitively intact older adults. Acute dark chocolate and cocoa ingestion and endothelial function: a randomized controlled crossover trial. Beneficial effects of dark chocolate on exercise capacity in sedentary subjects: underlying mechanisms. A double blind, randomized, placebo controlled trial. Reduction in blood pressure and serum lipids by lycosome formulation of dark chocolate and lycopene in prehypertension Effects of dark chocolate and cocoa consumption on endothelial function and arterial stiffness in overweight adults. Methylxanthines are the psycho-pharmacologically active constituents of chocolate Dark Chocolate Improves Coronary Vasomotion and Reduces Platelet Reactivity Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. Daily consumption of a dark chocolate containing flavanols and added sterol esters affects cardiovascular risk factors in a normotensive population with elevated cholesterol. Cocoa flavanols reduce N‐terminal pro‐B‐type natriuretic peptide in patients with chronic heart failure The effect of polyphenol-rich dark chocolate on fasting capillary whole blood glucose, total cholesterol, blood pressure and glucocorticoids in healthy overweight and obese subjects. Dark chocolate supplementation reduces the oxygen cost of moderate intensity cycling Short-term administration of dark chocolate is followed by a significant increase in insulin sensitivity and a decrease in blood pressure in healthy persons. Dark chocolate and reduced snack consumption in mildly hypertensive adults: an intervention study Central Arterial Hemodynamic Effects of Dark Chocolate Ingestion in Young Healthy People: A Randomized and Controlled Trial Effect of Chocolate and Yerba Mate Phenolic Compounds on Inflammatory and Oxidative Biomarkers in HIV/AIDS Individuals The effect of acute pre-exercise dark chocolate consumption on plasma antioxidant status, oxidative stress and immunoendocrine responses to prolonged exercise Dark chocolate or tomato extract for prehypertension: a randomised controlled trial Dark chocolate and vascular function in patients with peripheral artery disease: a randomized, controlled cross-over trial. Bioavailability of (-)-epicatechin upon intake of chocolate and cocoa in human volunteers
BACKGROUND Flavonoids are polyphenolic compounds of plant origin with antioxidant effects . Flavonoids inhibit LDL oxidation and reduce thrombotic tendency in vitro . Little is known about how cocoa powder and dark chocolate , rich sources of polyphenols , affect these cardiovascular disease risk factors . OBJECTIVE We evaluated the effects of a diet high in cocoa powder and dark chocolate ( CP-DC diet ) on LDL oxidative susceptibility , serum total antioxidant capacity , and urinary prostagl and in concentrations . DESIGN We conducted a r and omized , 2-period , crossover study in 23 healthy subjects fed 2 diets : an average American diet ( AAD ) controlled for fiber , caffeine , and theobromine and an AAD supplemented with 22 g cocoa powder and 16 g dark chocolate ( CP-DC diet ) , providing approximately 466 mg procyanidins/d . RESULTS LDL oxidation lag time was approximately 8 % greater ( P = 0.01 ) after the CP-DC diet than after the AAD .  Serum total antioxidant capacity measured by oxygen radical absorbance capacity was approximately 4 % greater ( P = 0.04 ) after the CP-DC diet than after the AAD and was positively correlated with LDL oxidation lag time ( r = 0.32 , P = 0.03 ) . HDL cholesterol was 4 % greater after the CP-DC diet ( P = 0.02 ) than after the AAD ; however , LDL-HDL ratios were not significantly different . Twenty-four-hour urinary excretion of thromboxane B(2 ) and 6-keto-prostagl and in F(1)(alpha ) and the ratio of the 2 compounds were not significantly different between the 2 diets . CONCLUSION Cocoa powder and dark chocolate may favorably affect cardiovascular disease risk status by modestly reducing LDL oxidation susceptibility , increasing serum total antioxidant capacity and HDL-cholesterol concentrations , and not adversely affecting prostagl and ins This study investigated the effects of regular consumption of dark chocolate ( DC ) , rich in cocoa polyphenols , on plasma metabolites , hormones , and markers of oxidative stress after prolonged exhaustive exercise . Twenty active men cycled at 60 % maximal oxygen uptake ( VO2max ) for 1.5 hr , with the intensity increased to 90 % VO2max for a 30-s period every 10 min , followed by a ride to exhaustion at 90 % VO2max . In the 2 wk before exercise participants consumed 40 g of DC or an isocarbohydrate-fat control cocoa liquor-free chocolate ( CON ) twice daily and once 2 hr before exercise in a r and omized , counterbalanced , crossover design . Venous blood sample s were taken immediately before exercise , postexercise ( fixed duration ) , postexhaustion , and after 1 hr of recovery . F2-isoprostanes were significantly lower ( post hoc tests : p < .001 ) at exhaustion and after 1 hr of recovery with DC . Oxidized low-density lipoproteins were significantly lower with DC ( p < .001 ) both before and after exercise and at exhaustion . DC was also associated with ~21 % greater rises in free fatty acids during exercise ( main effect : p < .05 ) . Changes in circulating glucose , insulin , glucagon , cortisol , and interleukin (IL)-6 , IL-10 , and IL-1ra were unaffected by treatment . Time to exhaustion at 90 % VO2max was not significantly different between trials ( 398 ± 204 and 374 ± 194 s for DC and CON , respectively ) . These results suggest that regular DC intake is associated with reduced oxidative-stress markers and increased mobilization of free fatty acids after exercise but has no observed effect on exercise performance Consumption of flavanol-rich dark chocolate ( DC ) has been shown to decrease blood pressure ( BP ) and insulin resistance in healthy subjects , suggesting similar benefits in patients with essential hypertension ( EH ) . Therefore , we tested the effect of DC on 24-hour ambulatory BP , flow-mediated dilation ( FMD ) , and oral glucose tolerance tests ( OGTTs ) in patients with EH . After a 7-day chocolate-free run-in phase , 20 never-treated , grade I patients with EH ( 10 males ; 43.7±7.8 years ) were r and omized to receive either 100 g per day DC ( containing 88 mg flavanols ) or 90 g per day flavanol-free white chocolate ( WC ) in an isocaloric manner for 15 days . After a second 7-day chocolate-free period , patients were crossed over to the other  treatment . Noninvasive 24-hour ambulatory BP , FMD , OGTT , serum cholesterol , and markers of vascular inflammation were evaluated at the end of each treatment . The homeostasis model assessment of insulin resistance ( HOMA-IR ) , quantitative insulin sensitivity check index ( QUICKI ) , and insulin sensitivity index ( ISI ) were calculated from OGTT values . Ambulatory BP decreased  after DC ( 24-hour systolic BP −11.9±7.7 mm Hg , P<0.0001 ; 24-hour diastolic BP −8.5±5.0 mm Hg , P<0.0001 ) but not WC . DC but not WC decreased HOMA-IR ( P<0.0001 ) , but it improved QUICKI , ISI , and FMD . DC also decreased serum LDL cholesterol ( from 3.4±0.5 to 3.0±0.6 mmol/L ; P<0.05 ) . In  summary , DC  decreased BP and serum LDL cholesterol , improved FMD , and ameliorated insulin sensitivity in hypertensives . These results suggest that , while balancing total calorie intake , flavanols from cocoa products may provide some cardiovascular benefit if included as part of a healthy diet for patients with EH BACKGROUND In recent years , there has been increased interest in the potential health-related benefits of antioxidant- and phytochemical-rich dark chocolate and cocoa . OBJECTIVE The objective of the study was to examine the short-term ( 6 wk ) effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health in healthy older adults . DESIGN A double-blind , placebo-controlled , fixed-dose , parallel-group clinical trial was used . Participants ( n = 101 ) were r and omly assigned to receive a 37-g dark chocolate bar and 8 ounces ( 237 mL ) of an artificially sweetened cocoa beverage or similar placebo products each day for 6 wk . RESULTS No significant group ( dark chocolate and cocoa or placebo)-by-trial ( baseline , midpoint , and end-of-treatment assessment s ) interactions were found for the neuropsychological , hematological , or blood pressure variables examined . In contrast , the midpoint and end-of-treatment mean pulse rate assessment s in the dark chocolate and cocoa group were significantly higher than those at baseline and significantly higher than the midpoint and end-of-treatment rates in the control group . Results of a follow-up question naire item on the treatment products that participants believed they had consumed during the trial showed that more than half of the participants in both groups correctly identified the products that they had ingested during the experiment . CONCLUSIONS This investigation failed to support the predicted beneficial effects of short-term dark chocolate and cocoa consumption on any of the neuropsychological or cardiovascular health-related variables included in this research . Consumption of dark chocolate and cocoa was , however , associated with significantly higher pulse rates at 3- and 6-wk treatment assessment BACKGROUND Studies suggest cardioprotective benefits of dark chocolate containing cocoa . OBJECTIVE This study examines the acute effects of solid dark chocolate and liquid cocoa intake on endothelial function and blood pressure in overweight adults . DESIGN R and omized , placebo-controlled , single-blind crossover trial of 45 healthy adults [ mean age : 53 y ; mean body mass index ( in kg/m(2 ) ) : 30 ] . In phase 1 , subjects were r and omly assigned to consume a solid dark chocolate bar ( containing 22 g cocoa powder ) or a cocoa-free placebo bar ( containing 0 g cocoa powder ) . In phase 2 , subjects were r and omly assigned to consume sugar-free cocoa ( containing 22 g cocoa powder ) , sugared cocoa ( containing 22 g cocoa powder ) , or a placebo ( containing 0 g cocoa powder ) . RESULTS Solid dark chocolate and liquid cocoa ingestion improved endothelial function ( measured as flow-mediated dilatation ) compared with placebo ( dark chocolate : 4.3 + /- 3.4 % compared with -1.8 + /- 3.3 % ; P < 0.001 ; sugar-free and sugared cocoa : 5.7 + /- 2.6 % and 2.0 + /- 1.8 % compared with -1.5 + /- 2.8 % ; P < 0.001 ) . Blood pressure decreased after the ingestion of dark chocolate and sugar-free cocoa compared with placebo ( dark chocolate : systolic , -3.2 + /- 5.8 mm Hg compared with 2.7 + /- 6.6 mm Hg ; P < 0.001 ; and diastolic , -1.4 + /- 3.9 mm Hg compared with 2.7 + /- 6.4 mm Hg ; P = 0.01 ; sugar-free cocoa : systolic , -2.1 + /- 7.0 mm Hg compared with 3.2 + /- 5.6 mm Hg ; P < 0.001 ; and diastolic : -1.2 + /- 8.7 mm Hg compared with 2.8 + /- 5.6 mm Hg ; P = 0.014 ) . Endothelial function improved significantly more with sugar-free than with regular cocoa ( 5.7 + /- 2.6 % compared with 2.0 + /- 1.8 % ; P < 0.001 ) . CONCLUSIONS The acute ingestion of both solid dark chocolate and liquid cocoa  improved endothelial function and lowered blood pressure  in overweight adults . Sugar content may attenuate these effects , and sugar-free preparations may augment them In heart failure patients the consumption of (-)-epicatechin ( (-)-Epi)-rich cocoa can restore skeletal muscle ( SkM ) mitochondrial structure and decrease biomarkers of oxidative stress . However , nothing is known about its effects on exercise capacity and underlying mechanisms in normal , sedentary subjects . Twenty normal , sedentary subjects ( ∼50 years old ) were r and omized to placebo or dark chocolate ( DC ) groups and consumed 20 g of the products for 3 months . Subjects underwent before and after treatment , bicycle ergometry to assess VO2 max and work , SkM biopsy to assess changes in mitochondrial density , function and oxidative stress and blood sampling to assess metabolic endpoints . Seventeen subjects completed the trial . In the DC group ( n = 9 ) , VO2 max increased ( 17 % increase , p = 0.056 ) as well as maximum work ( watts ) achieved ( p = 0.026 ) with no changes with placebo ( n = 8) . The DC group evidence d increases in HDL levels ( p = 0.005 ) and decreased triglycerides ( p = 0.07 ) . With DC , SkM evidence d significant increases in protein levels for LKB1 , AMPK and PGC1α and in their active forms ( phosphorylated AMPK and LKB1 ) as well as in citrate synthase activity while no changes were observed in mitochondrial density . With DC , significant increases in SkM reduced glutathione levels and decreases in protein carbonylation were observed . Improvements in maximum work achieved and VO2 max may be due to DC activation of upstream control systems and enhancement of SkM mitochondria efficiency . Larger clinical studies are warranted to confirm these observations Twenty-nine healthy volunteers aged 47–69 years old were r and omly assigned to a 28-day oral intake of different dark chocolate ( DC ) formulations . The main group received daily 30 g of proprietary lycopene-containing ( L-tug ) lycosome formulation of DC with enhanced bioavailability of cocoa flavanols . Two control groups daily consumed either 30 g of regular DC alone or along with 7 mg of lycopene , which corresponds to the amount of lycopene ingested with L-tug formulation . It was found that L-tug was more efficient in reducing diastolic blood pressure ( mean value of −6.22 mmHg , 95 % CI : 5.00 , 8.00 ) when compared with the regular DC group ( −3.00 mmHg , P < 0.05 ) or the group which ingested the DC and lycopene as two separate formulations ( mean reduction of −4 mmHg , 95 % CI : 2.47 , 6.00 , P = 0.0262 ) . Only marginal superiority for L-tug formulation in the reduction in systolic blood pressure was seen . However , the L-tug formulation was the only formulation of DC which affected serum lipids . There was a reduction in total cholesterol ( from median 228.00 mg/dL [ 95 % CI : 206.2 , 242.5 ] to 187.00 mg/dL [ 95 % CI : 166.2 , 202.2 , P < 0.05 ] ) with corresponding decline of low-density lipoprotein ( LDL ) cholesterol ( from a median of 166.00 mg/dL [ 95 % CI : 130.8 , 177.0 ] to 151.00 mg/dL [ 95 % CI : 122.8 , 167.4 ; P < 0.05 ] ) at the end of the intervention period . Similar decline was seen in serum triglycerides ( P < 0.05 ) . Serum high-density lipoprotein ( HDL ) cholesterol , glucose levels , and C-reactive protein ( CRP ) values remained statistically unchanged in all study groups throughout the intervention period . A superior biological activity of the L-tug lycosome formulation of DC extending beyond its antihypertensive effect to lipid-lowering ability opens up new possibilities for the use of DC for health purpose s helping to reduce daily caloric intake without compromising on the health benefits of DC consumption The consumption of cocoa and dark chocolate is associated with a lower risk of CVD , and improvements in endothelial function may mediate this relationship . Less is known about the effects of cocoa/chocolate on the augmentation index ( AI ) , a measure of vascular stiffness and vascular tone in the peripheral arterioles . We enrolled thirty middle-aged , overweight adults in a r and omised , placebo-controlled , 4-week , cross-over study . During the active treatment ( cocoa ) period , the participants consumed 37 g/d of dark chocolate and a sugar-free cocoa beverage ( total cocoa = 22 g/d , total flavanols ( TF ) = 814 mg/d ) . Colour-matched controls included a low-flavanol chocolate bar and a cocoa-free beverage with no added sugar ( TF = 3 mg/d ) . Treatments were matched for total fat , saturated fat , carbohydrates and protein . The cocoa treatment significantly increased the basal diameter and peak diameter of the brachial artery by 6 % ( + 2 mm ) and basal blood flow volume by 22 % . Substantial decreases in the AI , a measure of arterial stiffness , were observed in only women . Flow-mediated dilation and the reactive hyperaemia index remained unchanged . The consumption of cocoa had no effect on fasting blood measures , while the control treatment increased fasting insulin concentration and insulin resistance ( P= 0·01 ) . Fasting blood pressure ( BP ) remained unchanged , although the acute consumption of cocoa  increased resting BP by 4 mmHg . In summary , the high-flavanol cocoa and dark chocolate treatment was associated with enhanced vasodilation in both conduit and resistance arteries and was accompanied by significant reductions in arterial stiffness in women Rationale Liking , cravings and addiction for chocolate ( “ chocoholism ” ) are often explained through the presence of pharmacologically active compounds . However , mere “ presence ” does not guarantee psycho-activity . Objectives Two double-blind , placebo-controlled studies measured the effects on cognitive performance and mood of the amounts of cocoa powder and methylxanthines found in a 50 g bar of dark chocolate . Methods In study 1 , participants ( n=20 ) completed a test battery once before and twice after treatment administration . Treatments included 11.6 g cocoa powder and a caffeine and theobromine combination ( 19 and 250 mg , respectively ) . Study 2 ( n=22 ) comprised three post-treatment test batteries and investigated the effects of “ milk ” and “ dark ” chocolate levels of these methylxanthines . The test battery consisted of a long duration simple reaction time task , a rapid visual information processing task , and a mood question naire . Results Identical improvements on the mood construct “ energetic arousal ” and cognitive function were found for cocoa powder and the caffeine+theobromine combination versus placebo . In chocolate , both “ milk chocolate ” and “ dark chocolate ” methylxanthine doses improved cognitive function compared with “ white chocolate ” . The effects of white chocolate did not differ significantly from those of water . Conclusions A normal portion of chocolate exhibits psychopharmacological activity . The identical profile of effects exerted by cocoa powder and its methylxanthine constituents shows this activity to be confined to the combination of caffeine and theobromine . Methylxanthines may contribute to the popularity of chocolate ; however , other attributes are probably much more important in determining chocolate ’s special appeal and in explaining related self-reports of chocolate cravings and “ chocoholism ” Background — Dark chocolate has potent antioxidant properties . Coronary atherosclerosis is promoted by impaired endothelial function and increased platelet activation . Traditional risk factors , high oxidative stress , and reduced antioxidant defenses play a crucial role in the pathogenesis of atherosclerosis , particularly in transplanted hearts . Thus , flavonoid-rich dark chocolate holds the potential to have a beneficial impact on graft atherosclerosis . Methods and Results — We assessed the effect of flavonoid-rich dark chocolate compared with cocoa-free control chocolate on coronary vascular and platelet function in 22 heart transplant recipients in a double-blind , r and omized study . Coronary vasomotion was assessed with quantitative coronary angiography and cold pressor testing before and 2 hours after ingestion of 40 g of dark ( 70 % cocoa ) chocolate or control chocolate , respectively . Two hours after ingestion of flavonoid-rich dark chocolate  , coronary artery diameter was increased significantly ( from 2.36±0.51 to 2.51±0.59 mm , P<0.01 ) , whereas it remained unchanged after control  chocolate . Endothelium-dependent coronary vasomotion improved significantly after dark chocolate ( 4.5±11.4 % versus −4.3±11.7 % in the placebo group , P=0.01 ) . Platelet adhesion decreased from 4.9±1.1 % to 3.8±0.8 % ( P=0.04 ) in the dark chocolate group but remained unchanged in the control group . Conclusions — Dark chocolate  induces coronary vasodilation , improves coronary vascular function , and decreases platelet adhesion 2 hours after consumption . These immediate beneficial effects were paralleled by a significant reduction of serum oxidative stress and were positively correlated with changes in serum epicatechin concentration CONTEXT Regular intake of cocoa-containing foods is linked to lower cardiovascular mortality in observational studies . Short-term interventions of at most 2 weeks indicate that high doses of cocoa can improve endothelial function and reduce blood pressure ( BP ) due to the action of the cocoa polyphenols , but the clinical effect of low habitual cocoa intake on BP and the underlying BP-lowering mechanisms are unclear . OBJECTIVE To determine effects of low doses of polyphenol-rich dark chocolate on BP . DESIGN , SETTING , AND PARTICIPANTS R and omized , controlled , investigator-blinded , parallel-group trial involving 44 adults aged 56 through 73 years ( 24 women , 20 men ) with untreated upper-range prehypertension or stage 1 hypertension without concomitant risk factors . The trial was conducted at a primary care clinic in Germany between January 2005 and December 2006 . INTERVENTION Participants were r and omly assigned to receive for 18 weeks either 6.3 g ( 30 kcal ) per day of dark chocolate containing 30 mg of polyphenols or matching polyphenol-free white chocolate . MAIN OUTCOME MEASURES Primary outcome measure was the change in BP after 18 weeks . Secondary outcome measures were changes in plasma markers of vasodilative nitric oxide ( S-nitrosoglutathione ) and oxidative stress ( 8-isoprostane ) , and bioavailability of cocoa polyphenols . RESULTS From baseline to 18 weeks , dark chocolate intake reduced mean ( SD ) systolic BP by -2.9 ( 1.6 ) mm Hg ( P < .001 ) and diastolic BP by -1.9 ( 1.0 ) mm Hg ( P < .001 ) without changes in body weight , plasma levels of lipids , glucose , and 8-isoprostane . Hypertension prevalence declined from 86 % to 68 % . The BP decrease was accompanied by a sustained increase of S-nitrosoglutathione by 0.23 ( 0.12 ) nmol/L ( P < .001 ) , and a dark chocolate dose result ed in the appearance of cocoa phenols in plasma . White chocolate intake caused no changes in BP or plasma biomarkers . CONCLUSIONS Data in this relatively small sample of otherwise healthy individuals with above-optimal BP indicate that inclusion of small amounts of polyphenol-rich dark chocolate as part of a usual diet efficiently reduced BP and improved formation of vasodilative nitric oxide . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00421499 Previous studies with plant sterols ( PS ) and cocoa flavanols ( CF ) provide support for their dietary use in maintaining cardiovascular health . This double-blind , placebo-controlled , cross-over study evaluated the efficacy of daily consumption of a cocoa flavanol-containing dark chocolate bar with added PS on serum lipids , blood pressure , and other circulating cardiovascular health markers in a population with elevated serum cholesterol . We recruited 49 adults ( 32 women , 17 men ) with serum total cholesterol concentrations of 5.20 - 7.28 mmol/L and blood pressure of < or = 159/99 mm Hg . Following a 2-wk lead-in utilizing the AHA style diet , participants were r and omized into 2 groups and instructed to consume 2 cocoa flavanol-containing dark chocolate bars per day with ( 1.1 g sterol esters per bar ) or without PS . Each 419-kJ bar was nutrient-matched and contained approximately 180 mg CF . Participants consumed 1 bar 2 times per day for 4 wk then switched to the other bar for an additional 4 wk . Serum lipids and other cardiovascular markers were measured at baseline and after 4 and 8 wk . Blood pressure was measured every 2 wk . Regular consumption of the PS-containing chocolate bar result ed in reductions of 2.0 and 5.3 % in serum total and LDL cholesterol ( P < 0.05 ) , respectively . Consumption of CF also reduced systolic blood pressure at 8 wk ( -5.8 mm Hg ; P < 0.05 ) . Results indicate that regular consumption of chocolate bars containing PS and CF as part of a low-fat diet may support cardiovascular health by lowering cholesterol and improving blood pressure Abstract Aims Poor prognosis in chronic heart failure ( HF ) is linked to endothelial dysfunction for which there is no specific treatment currently available . Previous studies have shown reproducible improvements in endothelial function with cocoa flavanols , but the clinical benefit of this effect in chronic HF has yet to be determined . Therefore , the aim of this study was to assess the potential therapeutic value of a high dose of cocoa flavanols in patients with chronic HF , by using reductions in N‐terminal pro‐B‐type natriuretic peptide ( NT‐proBNP ) as an index of improved cardiac function . Methods and results Thirty‐two patients with chronic HF , stable on guideline ‐directed medical therapy , were r and omized to consume 50 g/day of high‐flavanol dark chocolate ( HFDC ; 1064 mg of flavanols/day ) or low‐flavanol dark chocolate ( LFDC ; 88 mg of flavanols/day ) for 4 weeks and then crossed over to consume the alternative dark chocolate for a further 4 weeks . Twenty‐four patients completed the study . After 4 weeks  of HFDC , NT‐proBNP ( mean decrease % ± st and ard deviation ) was significantly reduced compared with baseline ( −44 ± 69 % ) , LFDC ( −33 ± 72 % ) , and follow‐up ( −41 ± 77 % ) values . HFDC  also reduced diastolic blood pressure compared with values after LFDC ( −6.7 ± 10.1 mmHg ) . Conclusions Reductions in blood pressure and NT‐proBNP after HFDC  indicate decreased vascular resistance result ing in reduced left ventricular afterload . These effects warrant further investigation in patients with chronic HF Numerous studies indicate that polyphenol-rich chocolate reduces fasting blood glucose , blood pressure ( BP ) and total cholesterol in healthy individuals and hypertensives with or without glucose intolerance . The aim of the present study was to investigate the effect of two doses of polyphenol-rich dark chocolate ( DC ) on fasting capillary whole blood glucose , total cholesterol and BP and to examine whether improvements in these parameters are associated with changes in adrenocorticoid excretion in overweight and obese individuals . The study used a r and omised , single-blind , cross-over design where fourteen overweight and obese subjects were r and omised to either take 20 g DC with 500 mg polyphenols then 20 g DC with 1000 mg polyphenols or vice-versa . Participants followed each diet for 2 weeks separated by a 1-week washout period . It was observed that the 500 mg polyphenol dose was equally effective in reducing fasting blood glucose levels , systolic BP ( SBP ) and diastolic BP ( DBP ) as the 1000 mg polyphenol dose suggesting that a saturation effect might occur with increasing dose of polyphenols . There was also a trend towards a reduction in urinary free cortisone levels with both groups although it did not reach statistical significance . No changes in anthropometrical measurements were seen . We suggest that more research is required to investigate the mechanism(s ) by which polyphenol-rich foods influence health Background Dark chocolate ( DC ) is abundant in flavanols which have been reported to increase the bioavailability and bioactivity of nitric oxide ( NO ) . Increasing NO bioavailability has often demonstrated reduced oxygen cost and performance enhancement during submaximal exercise . Methods Nine moderately-trained male participants volunteered to undertake baseline ( BL ) measurements that comprised a cycle V.O2max$$ \overset{.}{V}{O}_{2 max } $ $ test followed by cycling at 80 % of their established gas exchange threshold ( GET ) for 20-min and then immediately followed by a two-minute time-trial ( TT ) . Using a r and omised crossover design participants performed two further trials , two weeks apart , with either 40 g of DC or white chocolate ( WC ) being consumed daily . Oxygen consumption , RER , heart rate and blood lactate ( BLa ) were measured during each trial . Results  DC consumption increased GET and TT performance compared to both BL and WC ( P < 0.05 ) .  DC consumption increased V.O2max$$ \overset{.}{V}{O}_{2 max } $ $ by 6 % compared to BL ( P < 0.05 ) , but did not reach statistical significance compared to WC . There were no differences in the moderate-intensity cycling for V.O2$$ \overset{.}{V}{O}_2 $ $ , RER , BLa and heart rate between conditions , although , V.O2$$ \overset{.}{V}{O}_2 $ $ and RER exhibited consistently lower trends following DC consumption compared to BL and WC , these did not reach statistical significance . Conclusion Chronic supplementation with DC result ed in a higher GET and enhanced TT performance . Consequently , ingestion of DC reduced the oxygen cost of moderate intensity exercise and may be an effective ergogenic aid for short- duration moderate intensity exercise BACKGROUND Numerous studies indicate that flavanols may exert significant vascular protection because of their antioxidant properties and increased nitric oxide bioavailability . In turn , nitric oxide bioavailability deeply influences insulin-stimulated glucose uptake and vascular tone . Thus , flavanols may also exert positive metabolic and pressor effects . OBJECTIVE The objective was to compare the effects of either dark or white chocolate bars on blood pressure and glucose and insulin responses to an oral-glucose-tolerance test in healthy subjects . DESIGN After a 7-d cocoa-free run-in phase , 15 healthy subjects were r and omly assigned to receive for 15 d either 100 g dark chocolate bars , which contained approximately 500 mg polyphenols , or 90 g white chocolate bars , which presumably contained no polyphenols . Successively , subjects entered a further cocoa-free washout phase of 7 d and then were crossed over to the other condition . Oral-glucose-tolerance tests were performed at the end of each period to calculate the homeostasis model assessment of insulin resistance ( HOMA-IR ) and the quantitative insulin sensitivity check index ( QUICKI ) ; blood pressure was measured daily . RESULTS HOMA-IR was significantly lower after dark than after white chocolate ingestion ( 0.94 + /- 0.42 compared with 1.72 + /- 0.62 ; P < 0.001 ) , and QUICKI was significantly higher after dark than after white chocolate ingestion ( 0.398 + /- 0.039 compared with 0356 + /- 0.023 ; P = 0.001 ) . Although within normal values , systolic blood pressure was lower after dark than after white chocolate ingestion ( 107.5 + /- 8.6 compared with 113.9 + /- 8.4 mm Hg ; P < 0.05 ) . CONCLUSION Dark , but not white , chocolate decreases blood pressure and improves insulin sensitivity in healthy persons Background Several studies have shown that cocoa and cocoa-containing foods have the potential to lower blood pressure and improve endothelial function . Most of the studies reporting the beneficial effects of dark chocolate on blood pressure have been short ( ≤ 4 weeks ) . The aim of the present 8-wks ( weeks ) study was to assess the effects of regular consumption of dark chocolate during a reduced snack consumption intervention on blood pressure and other cardiovascular risk factors in mildly hypertensive individuals . Design This was a r and omized , controlled , cross-over trial involving 22 adults ( 8 women , 14 men ) , aged 33–64 y , BMI 27.7 ± 3.7 kg/m2 with mild hypertension . During the intervention period ( 8-wks ) the participants reduced the intake of habitual snacks and replaced them with dark chocolate ( 49 g/day ) . In the control period , they only reduced the snacks without any added chocolate .  Data ( blood lipid profile , glucose , insulin , 24 h blood pressure ) was collected in the beginning and end of both periods ( intervention and control ) , and some variables also in the run-in and run-out periods ( weight , body fat percentage , blood pressure , arterial stiffness index , diet and physical activity ) . Results Daily consumption of dark chocolate had no effects on 24 h blood pressure , resting blood pressure ( mean ± SD , pre 142 ± 11.5/89 ± 8.4 mmHg vs. post 142 ± 14.2/88 ± 9.4 mmHg in systolic and diastolic blood pressure , respectively ) or arterial stiffness ( mean ± SD , pre 7.68 ± 0.88 vs. post 7.76 ± 0.89).Weight was reduced by 1.0 ± 2.2 kg during the control ( reduced snack only ) period , but was unchanged while eating chocolate ( p < 0.027 between the treatments ) . Conclusion The data collected in this study indicates that inclusion of dark chocolate daily in the diet had no significant effects on blood pressure or other cardiovascular risk factors during a reduced snack period . Trial registration Clinical Trials.gov identifier Introduction . The aim of this study was to assess the vascular benefits of dark chocolate in healthy and young individuals . Methods . A r and omized and controlled trial was carried out involving 60 healthy volunteers , r and omized into two groups :  control group ( CG ; n = 30 ) and  intervention group ( IG ; n = 30 ) . The IG ingested a daily dosage of 10 g of dark chocolate ( > 75 % cocoa ) for a month . Blood pressure ( BP ) , flow-mediated dilation ( FMD ) , arterial stiffness index ( ASI ) , aortic pulse wave velocity ( PWV ) , and pulse wave analysis ( PWA ) were assessed at baseline and one week after the one-month intervention period . Results . Arterial function improved after intervention in the IG , with PWV decreasing from 6.13 ± 0.41 m/s to 5.83 ± 0.53 m/s ( P = 0.02 ) , with no significant differences observed in the CG . A significant decrease in ASI ( 0.16 ± 0.01 to 0.13 ± 0.01 ; P < 0.001 ) and AiX ( −15.88 ± 10.75 to −22.57 ± 11.16 ; P = 0.07 ) was also depicted for the IG . Endothelial function improved in the IG , with the FMD increasing 9.31 % after the 1-month intervention ( P < 0.001 ) , with no significant variation in the CG . Conclusion . The daily ingestion of 10 g dark chocolate ( > 75 % cocoa ) during a month significantly improves vascular function in young and healthy individuals Flavonoids in cocoa and yerba mate have a beneficial role on inflammation and oxidative disorders . Their effect on HIV individuals has not been studied yet , despite the high cardiovascular risk of this population . This study investigated the role of cocoa and yerba mate consumption on oxidative and inflammatory biomarkers in HIV+ individuals . A cross-over , placebo-controlled , double-blind , r and omized clinical trial was conducted in 92 individuals on antiretroviral therapy for at least six months and at viral suppression . Participants were r and omized to receive either 65 g of chocolate or chocolate-placebo or 3 g of yerba mate or mate-placebo for 15 days each , alternating by a washout period of 15 days . At baseline , and at the end of each intervention regimen , data regarding anthropometry , inflammatory , oxidative and immunological parameters were collected . High-sensitivity C-reactive protein , fibrinogen , lipid profile , white blood cell profile and thiobarbituric acid reactive substances were assessed . There was a difference between mean concentrations of HDL-c ( ANOVA ; p ≤ 0.05 ) among the different regimens : dark chocolate , chocolate-placebo , yerba mate and mate-placebo . When a paired Student t-test was used for comparisons between mean HDL-c at baseline and after each regimen , the mean concentration of HDL-c was higher after supplementation with dark chocolate ( p = 0.008 ) Purpose Acute antioxidant supplementation may modulate oxidative stress and some immune perturbations that typically occur following prolonged exercise . The aims of the present study were to examine the effects of acutely consuming dark chocolate ( high polyphenol content ) on plasma antioxidant capacity , markers of oxidative stress and immunoendocrine responses to prolonged exercise . Methods Fourteen healthy men cycled for 2.5 h at ~60 % maximal oxygen uptake 2 h after consuming 100 g dark chocolate ( DC ) , an isomacronutrient control bar ( CC ) or neither ( BL ) in a r and omised-counterbalanced design . Results DC enhanced pre-exercise antioxidant status ( P = 0.003 ) and reduced by trend ( P = 0.088 ) 1 h post-exercise plasma free [ F2-isoprostane ] compared with CC ( also , [ F2-isoprostane ] increased post-exercise in CC and BL but not DC trials ) . Plasma insulin concentration was significantly higher pre-exercise ( P = 0.012 ) and 1 h post-exercise ( P = 0.026 ) in the DC compared with the CC trial . There was a better maintenance of plasma glucose concentration on the DC trial ( 2-way ANOVA trial × time interaction P = 0.001 ) , which decreased post-exercise in all trials but was significantly higher 1 h post-exercise ( P = 0.039 ) in the DC trial . There were no between trial differences in the temporal responses ( trial × time interactions all P > 0.05 ) of hypothalamic – pituitary – adrenal axis stress hormones , plasma interleukin-6 , the magnitude of leukocytosis and neutrophilia and changes in neutrophil function . Conclusion Acute DC consumption may affect insulin , glucose , antioxidant status and oxidative stress responses , but has minimal effects on immunoendocrine responses , to prolonged exercise Background Flavanol-rich chocolate and lycopene-rich tomato extract have attracted interest as potential alternative treatment options for hypertension , a known risk factor for cardiovascular morbidity and mortality . Treatment of prehypertension ( SBP 120–139/DBP 80–89 mmHg ) may forestall progression to hypertension . However , there has been only limited research into non-pharmacological treatment options for prehypertension . We investigated the effect of dark chocolate or tomato extract on blood pressure , and their acceptability as an ongoing treatment option in a prehypertensive population . Methods Our trial consisted of two phases : a r and omised controlled three-group-parallel trial over 12 weeks ( phase 1 ) followed by a crossover of the two active treatment arms over an additional 12-week period ( phase 2 ) . Group 1 received a 50 g daily dose of dark chocolate with 70 % cocoa containing 750 mg polyphenols , group 2 were allocated one tomato extract capsule containing 15 mg lycopene per day , and group 3 received one placebo capsule daily over 8 weeks followed by a 4-week washout period . In phase 2 the active treatment groups were crossed over to receive the alternative treatment . Median blood pressure , weight , and abdominal circumference were measured 4-weekly , and other characteristics including physical activity , general health , energy , mood , and acceptability of treatment were assessed by question naire at 0 , 8 and 20 weeks . We analysed changes over time using a linear mixed model , and one time point differences using Kruskal-Wallis , Fisher's-Exact , or t-tests . Results Thirty-six prehypertensive healthy adult volunteers completed the 6-month trial . Blood pressure changes over time within groups and between groups were not significant and independent of treatment . Weight and other characteristics did not change significantly during the trial . However , a marked difference in acceptability between the two treatment forms ( chocolate or capsule ) was revealed ( p < 0.0001 ) . Half of the participants allocated to the chocolate treatment found it hard to eat 50 g of dark chocolate every day and 20 % considered it an unacceptable long-term treatment option , whereas all participants found it easy and acceptable to take a capsule each day for blood pressure . Conclusion Our study did not find a blood pressure lowering effect of dark chocolate or tomato extract in a prehypertensive population . Practicability of chocolate as a long-term treatment option may be limited . Trial registration http://www.anzctr.org.au Identifier : Flavonoid-rich dark chocolate has positive effects on vascular function in healthy subjects and in patients at risk of atherosclerosis . The impact of dark chocolate on endothelial and microvascular function in patients with symptomatic peripheral artery disease ( PAD ) has not been investigated so far . In an investigator blinded , r and omized , controlled , cross-over trial we assessed the effect of flavonoid-rich dark chocolate and cocoa-free control chocolate on flow-mediated dilatation ( FMD ) of the brachial artery and on microvascular function ( assessed by Laser Doppler fluxmetry ) in 21 patients with symptomatic ( Fontaine stage II ) PAD . Measurements were done in each patient on 2 single days , with an interval of 7 days , at baseline and at 2 hours after ingestion of 50 g dark chocolate or 50 g white chocolate , respectively . FMD remained unchanged after intake of dark chocolate ( baseline and 2 hours after ingestion , % : 5.1 [ IQR 4.4 to 7.3 ] and 5.5 [ IQR 3.9 to 10.4 ] ; p = 0.57 , and after intake of white chocolate ( baseline and 2 hours after ingestion , % : 6.4 [ IQR 4.5 to 11.4 ] and 4.4 [ IQR 2.6 to 8.7 ] ; p = 0.14 . Similarly , microcirculatory parameters were not significantly altered after intake of any chocolate compared with the respective baseline values . In conclusion , a single consumption of 50 g dark chocolate has no effect on endothelial and microvascular function in patients with symptomatic PAD We evaluated the levels of  (-)-epicatechin ( EC )  and its metabolites in plasma and urine after intake of chocolate or cocoa by male volunteers . EC metabolites were analyzed by HPLC and LC/MS after glucuronidase and /or sulfatase treatment . The maximum levels of total EC metabolites in plasma were reached 2 hours after either chocolate or cocoa intake . Sulfate , glucuronide , and sulfoglucuronide ( mixture of sulfate and glucuronide ) conjugates of nonmethylated EC were the main metabolites present in plasma rather than methylated forms . Urinary excretion of total EC metabolites within 24 hours after chocolate or cocoa intake was 29.8 ± 5.3 % and 25.3 ± 8.1 % of total EC intake . EC in chocolate and cocoa was partly absorbed and was found to be present as a component of various conjugates in plasma , and these were rapidly excreted in urine
Conclusion : Cocoa/DC supplementation does not reduce anthropometric measures significantly .
However subgroup analysis regarding dose ( ≥ 30 g/day ) and duration ( between 4 to 8 weeks ) revealed significant reduction of body weight and BMI
ABSTRACT Background : Cocoa and dark chocolate ( DC ) have been reported to be effective for health promotion ; however the exact effect of cocoa/DC on anthropometric measures have not been yet defined .