Effects of flavanols and procyanidins-rich cocoa consumption on metabolic syndrome: an update review (2013-2023).

Studies indicated that cocoa-based products effectively mitigate the risks associated with metabolic syndrome (MetS), however, the effect varies based on cocoa types, dosages, and study durations. This review aimed to determine the flavanol-rich cocoa consumption on MetS outcomes within the last decade (2013-2023), adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Seven randomized-controlled trials (RCTs) used cocoa-based products containing 0.3-1680 mg flavanol monomers and 3.5-1270 mg procyanidins. Cocoa-based products beneficially reduced glycemic response, blood pressure and lipid profiles. However, this review highlights little evidence pinpointing the best cocoa products type and required dosage for the observed effects. Further intervention aiming to improve MetS should justify the selection and concentration of flavanols (monomers and procyanidins). A robust study design should consider registering the trials before study commencement, consider multicenter RCT trials, and adjust for potential covariates that might "masked" the outcomes.

Investigating the physicochemical properties, sensory profile and consumer acceptability of beetroot dark chocolate.

BACKGROUND: The incorporation of functional food ingredients in chocolate that seek to eliminate, if not completely, most of the added sugar content, as well as the use of alternative chocolate production techniques, have gained popularity in recent years. This study aimed to incorporate red beetroot powder into dark chocolate and investigate the effect of red beetroot powder concentration and processing time in a melanger on the physicochemical properties, sensory profile and consumer acceptability of beetroot dark chocolate. RESULTS: The addition of red beetroot powder increased the moisture content, particle size distribution and hardness of the chocolates, while the opposite was true for processing time with no effect on the colour. Except for taste, which had an average score of 3.2 ± 1.8 on the 7-point hedonic scale, consumers scored all the other sensory attributes of the chocolates above 4.0. Among the chocolates with red beetroot powder, samples with a 15% red beetroot powder addition had a high average overall acceptability score of >5, while the 30% sample scored <4. CONCLUSION: Red beetroot powder can be used to replace sugar in dark chocolate without affecting its physicochemical properties, sensory profile or consumer acceptability. However, the target market should be considered when determining the level of red beetroot powder incorporation in terms of chocolate taste. This research has the potential to improve the overall health-promoting properties of dark chocolate by eliminating added sugar (partially or completely). It would also help to diversify beetroot utilization, allow small-scale processors to venture into chocolate production and expand the small-scale chocolate value chain. © 2024 Society of Chemical Industry.

The impact of different dark chocolate dietary patterns on synaptic potency and plasticity in the hippocampal CA1 area of the rats under chronic isolation stress.

INTRODUCTION: Although, stress causes brain dysfunction, consumption of dark chocolate (DC) has positive effects on brain functions. The current study investigated the impact of different DC dietary patterns on synaptic potency and plasticity in the hippocampal CA1 area, as well as food intake and body weight in rats under chronic isolation stress. METHODS: Thirty-five rats were allocated into five groups of control, stress, and stress accompanied by three DC dietary patterns (stress-compulsory, -optional, and -restricted DC). The stressed rats on a compulsory diet only received DC and the ones on an optional diet received unlimited chow and/or DC. Also, the stressed rats on a restricted diet each received chow freely and only 4 g DC daily. Subsequently, the slope and amplitude of field excitatory postsynaptic potentials (fEPSPs) were assessed based on the Input-Output (I/O) curves and after the longterm potentiation (LTP). Moreover, food intake and body weight were measured for all groups. RESULTS: The fEPSP slope and amplitude in the I/O curves and after LTP decreased significantly in the stress group compared to the control group. Although the slope and amplitude both enhanced non-significantly in the optional DC diet, these parameters changed significantly in both compulsory and restricted DC dietary patterns compared to the stress group. Also, food intake and body weight decreased significantly in all DC groups. CONCLUSION: The compulsory and restricted DC dietary patterns reversed the harmful effects of chronic isolation stress on the hippocampal synaptic potency, plasticity, learning, and memory. All DC diets, especially compulsory and restricted ones, reduced food intake and body weight.

Food Fortification Using Spray-Dried Emulsions of Fish Oil Produced with Maltodextrin, Plant and Whey Proteins-Effect on Sensory Perception, Volatiles and Storage Stability.

Fortification of foods with fish oil rich in n-3 fatty acids improves the nutritional value, but creates challenges with flavor and oxidative stability, especially during storage. Pea, soy, and sunflower proteins were used in combination with whey protein or maltodextrin to encapsulate fish oil by spray-drying. The use of whey protein compared with maltodextrin as wall material improved oxidative stability of spray-dried emulsions, although the use of whey protein increased the number of observed cracks in outer shell of the particles. Non- and encapsulated oil were used in cookies and chocolates to examine flavor characteristics by generic descriptive analysis and volatile products by solid-phase microextraction with gas chromatography-mass spectrometry. A long-term storage test at room temperature was conducted to evaluate the oxidative stability of the food models. Fortification changed the texture, odor, and flavor of the food models with fishy flavor being the most impactful attribute. For both food models, use of pea protein with maltodextrin resembled attributes of control the best. Fortification and encapsulation material also affected volatile profiles of food models. Both non-encapsulated oil and whey protein formulations performed well in regard to oxidative stability for both food models. Generally, the cookie model showed more potential for fortification than the chocolate one.

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.

Physicochemical, Antioxidant, Microstructural Properties and Bioaccessibility of Dark Chocolate with Plant Extracts.

In this study, dark chocolates (DCh) containing zinc lactate (ZnL) were enriched with extracts from elderberries (EFrE), elderflowers (EFlE), and chokeberries (ChFrE) to improve their functional properties. Both dried plant extracts and chocolates were analyzed for antioxidant capacity (AC) using four different analytical methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion-reducing antioxidant capacity (CUPRAC), and ferric-reducing antioxidant power (FRAP), while total phenolic content (TPC) was determined by Folin-Ciocalteu (F-C) assay. An increase in antioxidant properties of fortified chocolates was found, and the bioaccessibility of their antioxidants was evaluated. The highest AC and TPC were found in ChFrE and chocolate with chokeberries (DCh + ChFrE) before and after simulated in vitro digestion. Bioaccessibility studies indicated that during the simulated digestion the AC of all chocolates reduced significantly, whereas insignificant differences in TPC results were observed between chemical and physiological extracts. Moreover, the influence of plant extracts on physicochemical parameters such as moisture content (MC), fat content (FC), and viscosity of chocolates was estimated. Furthermore, scanning electron microscopy with dispersive energy spectroscopy (SEM-EDS) was used to analyze surface properties and differences in the chemical composition of chocolates without and with additives.

The influence of different concentrations of flavanol chocolate bars under acute supplement conditions on exercise and performance.

OBJECTIVE: The purpose of this study was to assess the effects and acute dosage of different flavanol concentrations in a dark chocolate bar on physiological parameters during steady state (SS) and incremental exercise. METHODS: In a double-blind, randomised, crossover study, 15 healthy participants with a mean ± SD age of 30 ± 7 years; stature 176.8 ± 8.6 cm and body mass 80.3 ± 8.4 kg supplemented with high flavanol (HF) (1060 mg), moderate flavanol (MF) (746 mg), low flavanol (LF) (406 mg), or a control (CON) (88 mg) chocolate bar (~ 34 g), 2 h prior to 40 min of SS cycling (80% gas-exchange threshold) followed by an incremental test to volitional fatigue. During the SS cycle oxygen consumption ([Formula: see text]), respiratory exchange ratio (RER) and heart rate (HR) were continuously monitored. Plasma samples were collected prior to commencing exercise to determine nitrate (NO3-) and nitrite (NO2-) levels under each condition. RESULTS: There was no observed effect between flavanol concentrations on [Formula: see text], RER, and HR during SS cycling (P > 0.05). [Formula: see text], peak power, HR peak, and RER peak also did not significantly differ between conditions (P > 0.05). There was a small trend for higher plasma NO2- levels following higher flavanol concentration; however, this did not reach statistical significance (P > 0.05). CONCLUSION: Acute supplementation with cocoa of differing flavanol concentrations does not appear to have any effect on exercise and performance. It is plausible that longer flavanol supplementation periods might have greater accumulative effects and thus may potentially elicit a larger effect.

Cocoa Shell as a Step Forward to Functional Chocolates-Bioactive Components in Chocolates with Different Composition.

Chocolate is considered as both caloric and functional food. Its nutritional properties may be improved by addition of fiber; however, this may reduce polyphenols content. The aim of this research was to determine the influence of cocoa shell addition (as a source of fiber) and its combination with different ingredients (cocoa butter equivalents (CBE), emulsifiers, dairy ingredients) on polyphenols of dark and milk chocolates. Total polyphenol (TPC) and total flavonoid (TFC) contents were determined spectrophotometrically, identification and quantification of individual compounds by high pressure liquid chromatography and antioxidant capacity by ferric reducing antioxidant power (FRAP) assay. Results showed that even though addition of cocoa shell to chocolate results in reduced contents of TPC, TFC, and individual compounds, it is not significant compared to ones reported by other authors for commercial chocolates. Other ingredients influence determined values for all investigated parameters; however, additional research is needed to reveal exact mechanisms and implications.

Key Aroma Compounds of Dark Chocolates Differing in Organoleptic Properties: A GC-O Comparative Study.

Dark chocolate samples were previously classified into four sensory categories. The classification was modelled based on volatile compounds analyzed by direct introduction mass spectrometry of the chocolates' headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory categories. To address the problem, a gas chromatography-olfactometry (GC-O) study was conducted by 12 assessors using a comparative detection frequency analysis (cDFA) approach on 12 exemplary samples. A nasal impact frequency (NIF) difference threshold combined with a statistical approach (Khi² test on k proportions) revealed 38 discriminative key odorants able to differentiate the samples and to characterize the sensory categories. A heatmap emphasized the 19 most discriminant key odorants, among which heterocyclic molecules (furanones, pyranones, lactones, one pyrrole, and one pyrazine) played a prominent role with secondary alcohols, acids, and esters. The initial sensory classes were retrieved using the discriminant key volatiles in a correspondence analysis (CA) and a hierarchical cluster analysis (HCA). Among the 38 discriminant key odorants, although previously identified in cocoa products, 21 were formally described for the first time as key aroma compounds of dark chocolate. Moreover, 13 key odorants were described for the first time in a cocoa product.

Is there a relationship between chocolate consumption and symptoms of depression? A cross-sectional survey of 13,626 US adults.

OBJECTIVE: To examine associations between chocolate consumption and depressive symptoms in a large, representative sample of US adults. METHODS: The data were from 13,626 adults (≥20 years) participating in the National Health and Nutrition Examination Survey between 2007-08 and 2013-14. Daily chocolate consumption was derived from two 24-hr dietary recalls. Depressive symptoms were assessed using the Patient Health Questionnaire (PHQ-9), with scores ≥10 indicating the presence of clinically relevant symptoms. We used multivariable logistic regression to test associations of chocolate consumption (no chocolate, non-dark chocolate, dark chocolate) and amount of chocolate consumption (grams/day, in quartiles) with clinically relevant depressive symptoms. Adults with diabetes were excluded and models controlled for relevant sociodemographic, lifestyle, health-related, and dietary covariates. RESULTS: Overall, 11.1% of the population reported any chocolate consumption, with 1.4% reporting dark chocolate consumption. Although non-dark chocolate consumption was not significantly associated with clinically relevant depressive symptoms, significantly lower odds of clinically relevant depressive symptoms (OR = 0.30, 95%CI 0.21-0.72) were observed among those who reported consuming dark chocolate. Analyses stratified by the amount of chocolate consumption showed participants reporting chocolate consumption in the highest quartile (104-454 g/day) had 57% lower odds of depressive symptoms than those who reported no chocolate consumption (OR = 0.43, 95%CI 0.19-0.96) after adjusting for dark chocolate consumption. CONCLUSIONS: These results provide some evidence that consumption of chocolate, particularly dark chocolate, may be associated with reduced odds of clinically relevant depressive symptoms. Further research capturing long-term chocolate consumption and using a longitudinal design are required to confirm these findings and clarify the direction of causation.

Sensory and physicochemical characteristics of dark chocolate bar with addition of cinnamon (Cinnamomum burmannii) bark oleoresin microcapsule.

Indonesia is one of the world's most prominent producers of cocoa and cinnamon. Dark chocolate bars and Cinnamomum burmannii are rich in antioxidants. The addition of a cinnamon oleoresin to a dark chocolate bar has not been previously studied due to its strong consistency and sticky texture. Microencapsulation was used to cover the undesirable properties of oleoresin, and the addition of cinnamon bark oleoresin microcapsules was expected to improve the functional properties and influence the characteristics of dark chocolate bars. This study aimed to determine the effects of adding various concentrations of cinnamon bark oleoresin microcapsules (4%/F1, 6%/F2, and 8%/F3) to dark chocolates bars on their sensory, physical, and chemical characteristics and to define the best formula of a dark chocolate bar. The results showed that various concentrations of cinnamon bark oleoresin microcapsules led different trends for each evaluation, and the best formula resulted from the addition of cinnamon bark oleoresin microcapsules to a dark chocolate bar (8%) that is accepted by the panellists. This bar had the hardest texture, the highest total phenol and antioxidant activities, and the lowest moisture content, and it was classified as having a high potency of vitamin E (tocopherol).

A randomised controlled trial of consumption of dark chocolate in pregnancy to reduce pre-eclampsia: Difficulties in recruitment, allocation and adherence.

In 2013-2014 we undertook a randomised controlled trial (RCT) to determine whether the daily ingestion of dark chocolate during pregnancy could reduce the incidence of pre-eclampsia in primigravidae. However, after two years we had not succeeded in recruiting more than 3.5% of the number of participants required to answer the research question, and the trial was halted. We also reviewed the literature on this topic and found it to be limited. We report here our findings and discuss the difficulties facing researchers in this area.

A comparison of two low-calorie sweeteners and sugar in dark chocolate on sensory attributes and emotional conceptualisations.

Reducing sugar consumption is an important aspect in the prevention of and fight against obesity. A broader understanding of consumers' perceptions of low-calorie sweeteners is needed. This study examined two low-calorie sweeteners, tagatose and stevia, in comparison to sugar in dark chocolate. A total of 219 consumers participated in this study and rated overall liking and sensory attributes. Participants also listed their emotional conceptualisations upon consumption and were assessed on emotional eating behaviour and health and taste attitudes. The chocolate with tagatose was perceived as more similar to the chocolate with sugar than with stevia on overall liking, texture, bitterness, duration of aftertaste and intensity of aftertaste. Furthermore, chocolate with sugar and chocolate with tagatose both elicited positive emotional conceptualisations whereas chocolate with stevia elicited negative emotional conceptualisations. In conclusion, dark chocolate with tagatose did not significantly differ from sugar in overall liking, most sensory attributes and emotional conceptualisation.

Daily Consumption of Chocolate Rich in Flavonoids Decreases Cellular Genotoxicity and Improves Biochemical Parameters of Lipid and Glucose Metabolism.

In recent years, the incidence of atherosclerotic cardiovascular disease, obesity, and diabetes has increased largely worldwide. In the present work, we evaluated the genoprotective effect of the consumption of flavonoids-rich chocolate on 84 young volunteers. Biochemical indicators related to the prevention and treatment of cardiovascular risk and metabolic syndrome were also determined. A randomized, placebo-controlled, double-blind study was performed in the Autonomous University of Baja California. The treatments comprised the daily consumption of either 2 g of dark chocolate containing 70% cocoa, or 2 g of milk chocolate, for 6 months. The total amount of phenolic compounds and flavonoids was determined in both types of chocolate. Anthropometrical and Biochemical parameters were recorded prior to and after the study. The evaluation of the genotoxicity in buccal epithelial cells was performed throughout the duration of the study. Flavonoids from cocoa in dark chocolate significantly prevented DNA damage, and improved the nucleus integrity of cells. This effect could be related to the antioxidant capacity of the dark chocolate that decreased cellular stress. Biochemical parameters (total cholesterol, triglycerides, and LDL-cholesterol level in blood) and anthropometrical parameters (waist circumference) were improved after six months of daily intake of 2 g of dark chocolate with a 70% of cocoa.

Dark chocolate attenuates intracellular pro-inflammatory reactivity to acute psychosocial stress in men: A randomized controlled trial.

Flavanol-rich dark chocolate consumption relates to lower risk of cardiovascular mortality, but underlying mechanisms are elusive. We investigated the effect of acute dark chocolate consumption on inflammatory measures before and after stress. Healthy men, aged 20-50years, were randomly assigned to a single intake of either 50g of flavanol-rich dark chocolate (n=31) or 50g of optically identical flavanol-free placebo-chocolate (n=34). Two hours after chocolate intake, both groups underwent the 15-min Trier Social Stress Test. We measured DNA-binding-activity of the pro-inflammatory transcription factor NF-κB (NF-κB-BA) in peripheral blood mononuclear cells, as well as plasma and whole blood mRNA levels of the pro-inflammatory cytokines IL-1ß and IL-6, and the anti-inflammatory cytokine IL-10, prior to chocolate intake as well as before and several times after stress. We also repeatedly measured the flavanol epicatechin and the stress hormones epinephrine and cortisol in plasma and saliva, respectively. Compared to the placebo-chocolate-group, the dark-chocolate-group revealed a marginal increase in IL-10 mRNA prior to stress (p=0.065), and a significantly blunted stress reactivity of NF-κB-BA, IL-1ß mRNA, and IL-6 mRNA (p's⩽0.036) with higher epicatechin levels relating to lower pro-inflammatory stress reactivity (p's⩽0.033). Stress hormone changes to stress were controlled. None of the other measures showed a significant chocolate effect (p's⩾0.19). Our findings indicate that acute flavanol-rich dark chocolate exerts anti-inflammatory effects both by increasing mRNA expression of the anti-inflammatory cytokine IL-10 and by attenuating the intracellular pro-inflammatory stress response. This mechanism may add to beneficial effects of dark chocolate on cardiovascular health.

Variation of total aroma and polyphenol content of dark chocolate during three phase of conching.

Variation in the volatiles, total polyphenol, theobromine and caffein was investigated both qualitatively and quantitatively for all phases of conching with GC/MS/SPME, HPLC, GC/O, and UV-visible spectrophotometry. The volatile compounds being identified during the three phases consisted of aldehydes, ketones, pyrazines, acids, alcohols and esters. The number and concentration of these compounds were observed to be 31-25,681 ppb, 44-34,838 ppb and 44-29,809 ppb in the dry, pasty, and liquid phases respectively. The odor of dark chocolate was described as nutty, sweet, caramel, green and chocolate using olfactometry. The percent decrease in the concentration of total polyphenol, caffein and theobromine was observed to be only 3.0, 11.0, and 32.0 respectively.

Energy compensation in the real world: good compensation for small portions of chocolate and biscuits over short time periods in complicit consumers using commercially available foods.

While investigations using covert food manipulations tend to suggest that individuals are poor at adjusting for previous energy intake, in the real world adults rarely consume foods of which they are ill-informed. This study investigated the impact in fully complicit consumers of consuming commercially available dark chocolate, milk chocolate, sweet biscuits and fruit bars on subsequent appetite. Using a repeated measures design, participants received four small portions (4 × 10-11 g) of either dark chocolate, milk chocolate, sweet biscuits, fruit bars or no food throughout five separate study days (counterbalanced in order), and test meal intake, hunger, liking and acceptability were measured. Participants consumed significantly less at lunch following dark chocolate, milk chocolate and sweet biscuits compared to no food (smallest t(19) = 2.47, p = 0.02), demonstrating very good energy compensation (269-334%). No effects were found for fruit bars (t(19) = 1.76, p = 0.09), in evening meal intakes (F(4,72) = 0.62, p = 0.65) or in total intake (lunch + evening meal + food portions) (F(4,72) = 0.40, p = 0.69). No differences between conditions were found in measures of hunger (largest F(4,76) = 1.26, p = 0.29), but fruit bars were significantly less familiar than all other foods (smallest t(19) = 3.14, p = 0.01). These findings demonstrate good compensation over the short term for small portions of familiar foods in complicit consumers. Findings are most plausibly explained as a result of participant awareness and cognitions, although the nature of these cognitions cannot be discerned from this study. These findings however, also suggest that covert manipulations may have limited transfer to real world scenarios.

Dark chocolate: an obesity paradox or a culprit for weight gain?

Obesity remains a major public health challenge, and its prevalence is dramatically increasing. Diet and exercise are typically recommended to prevent and manage obesity; however, the results are often conflicting. Polyphenols, a class of phytochemicals that have been shown to reduce the risk factors for diabetes type II and cardiovascular diseases, are recently suggested as complementary agents in the management of obesity through several mechanisms such as decreasing fat absorption and/or fat synthesis. Dark chocolate, a high source of polyphenols, and flavanols in particular, has lately received attention for its possible role in modulating obesity because of its potential effect on fat and carbohydrate metabolism, as well as on satiety. This outcome was investigated in animal models of obesity, cell cultures and few human observational and clinical studies. The research undertaken to date has shown promising results, with the possible implication of cocoa/dark chocolate in the modulation of obesity and body weight through several mechanisms including decreasing the expression of genes involved in fatty acid synthesis, reducing the digestion and absorption of fats and carbohydrates and increasing satiety.

Effectiveness of Dark Chocolate and Carrot Juice on Perceived Labor Pain During Stage 1 of Birth Delivery Among Primigravida: A Quasi-Experimental Study.

Background: Dark chocolate and carrot juice may positively decline the pain. However, there is a lack evidence the impact of combination dark chocolate and carrot juice on labor pain during stage 1 of birth delivery among primigravida. Objective: This study aimed to examine the effectiveness of dark chocolate and carrot juice on perceived labor pain during stage 1 of birth delivery among primigravida. Methods: This was a quasi-experimental study with participants who received dark chocolate (n=30), carrot juice (n=30), and control group (n=30). Pain level was assessed by using the Numeric Pain Rating Scale (NPRS) before the intervention and at 30 hours after intervention. The Chi-square and one-way analysis of variance tests and general equational model were used. Results: Data were collected and analyzed before and after 60 minutes of intervention. Our results showed a significant interaction between the group and time, with both groups independently ameliorating labor pain. Conclusion: Dark chocolate and carrot juice therapies independently lowered pain labor in primigravida mothers, making them a viable treatment for advanced pain labor.

Effect of dark chocolate/ cocoa consumption on oxidative stress and inflammation in adults: A GRADE-assessed systematic review and dose-response meta-analysis of controlled trials.

BACKGROUND: Oxidative stress and inflammation play critical roles in the pathogenesis of many chronic diseases. Dark chocolate (DC)/cocoa, as a rich source of polyphenols like flavonoids, has anti-inflammatory and antioxidant properties that may confer health benefits, but findings in this context are inconsistent. OBJECTIVE: This systematic review and dose-response meta-analysis aimed to provide a comprehensive overview of the controlled trials (CTs) that have examined the effects of DC/cocoa on oxidative stress and inflammation biomarkers in adults. SEARCH METHODS: Databases including PubMed, Web of Science, and Scopus, were searched for relevant studies through April 2024. SELECTION CRITERIA: Studies assessed C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), nitric oxide (NO), P-selectin, E-selectin and thiobarbituric acid reactive substances (TBARS) in adults were included. DATA ANALYSIS: Based on the random-effects model, we calculated WMDs, SMDs and 95 % confidence intervals (CIs). Sensitivity, sub-group, meta-regression and dose-response analyses were also conducted. RESULTS: Thirty-three eligible CTs with 1379 participants were included. All studies reported the intervention types (cocoa powder, beverages and chocolate bars) and dosage. However, sixteen studies didn't do/report testing for purity and potency by independent groups. Also, none of the studies mentioned the risk of contamination with heavy metals. Another limitation was the lack of blinding assessment in studies. DC/cocoa significantly reduced MDA (SMD: -0.69, 95 %CI: -1.17, -0.2, p = 0.005) and increased NO levels (SMD: 2.43, 95 %CI: 1.11,3.75, p < 0.001); However, it has no significant effects on the other outcomes. Greater anti-inflammatory effects occurred at higher flavonoid doses (>450 mg/day) and for shorter durations (≤4 weeks) in the non-healthy participants. Non-linear dose-response relationships between cocoa dosage and CRP level and also between flavonoid dosage and IL-6 level were observed. Based on the GRADE evaluation, just CRP and MDA results were considered as high certainty evidence and the other outcomes results were categorized as very low to moderate certainty. CONCLUSIONS: DC/cocoa may improve systemic oxidative status and inflammation in adults. However, further studies should be performed to determine its benefits.