Dark Chocolate Effect on Serum Adiponectin, Biochemical and Inflammatory Parameters in Diabetic Patients: A Randomized Clinical Trial

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.

Effects of Cocoa Consumption on Cardiometabolic Risk Markers: Meta-Analysis of Randomized Controlled Trials

BACKGROUND

We conducted a systematic review and meta-analysis to examine the effect of dietary intake of cocoa on anthropometric measurements, lipid and glycemic profiles, and blood pressure levels in adults, with and without comorbidities.

METHODS

The databases used were MEDLINE (PubMed), EMBASE, Web of Science, Cochrane, LILACS, and SciELO. The eligible studies were randomized clinical trials (RCTs) involving adults undergoing cocoa consumption (cocoa extract or ≥70% cocoa dark chocolate) for ≥4 weeks that evaluated at least one of the following markers: body weight, body mass index (BMI), waist/abdominal circumference, total cholesterol, LDL-c, triglycerides, HDL-c, blood glucose, glycated hemoglobin (HbA1c), and systolic and diastolic blood pressure (SBP/DBP).

RESULTS

Thirty-one studies were included, totaling 1986 participants. Cocoa consumption showed no effects on body weight, BMI, waist circumference, triglycerides, HDL-c and HbA1c. Yet, there was a reduction in total cholesterol (-8.35 mg/dL, 95% CI -14.01; -2.69 mg/dL), LDL-c (-9.47 mg/dL, 95% CI -13.75; -5.20 mg/dL), fasting blood glucose (-4.91 mg/dL, 95% CI -8.29; -1.52 mg/dL), SBP (-2.52 mmHg, 95% CI -4.17; -0.88 mmHg), and DBP (-1.58 mmHg, 95% CI -2.54; -0.62 mmHg).

CONCLUSIONS

The consumption of cocoa showed protective effects on major cardiometabolic risk markers that have a clinical impact in terms of cardiovascular risk reduction.

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.

The action of phytochemicals present in cocoa in the prevention of vascular dysfunction and atherosclerosis

BACKGROUND

Chronic non-communicable diseases, including cardiovascular diseases (CVDs), have caused many deaths worldwide. Atherosclerotic plaque formation is common in individuals with CVDs. Thus, antioxidant and anti-inflammatory nutritional strategies can be used to prevent or inhibit this process. Due to its higher concentrations of cocoa, dark chocolate is considered a functional food due to the presence and action of phytochemical compounds, with anti-inflammatory and antioxidant actions. However, the recommended amounts of these compounds to prevent atherosclerosis have not yet been fully elucidated.

AIM

The aim of the studywas to review the effects of cocoa and dark chocolate intake on the prevention of cardiovascular dysfunction and atherosclerosis.

METHODS

This narrative review was based on a search of PubMed and Lilacs. The search was conducted from September 2021 to February 2022 using the following keywords: flavonoids, cocoa, atherosclerosis, oxidative stress, and inflammation. The inclusion criteria were original articles, meta-analyses, and experimental and clinical studies published between 2002 and 2022 in English, focusing on the subject addressed. The exclusion criteria were the title and abstract reading and duplication of articles in the databases.

RESULTS

The antioxidant and anti-inflammatory functions of phytochemicals in cocoa and dark chocolate are related to the modulation of nitric oxide through activation/phosphorylation and acting as a vasodilator. Furthermore, these phytochemicals reduce the formation of reactive oxygen species and activate antioxidant enzymes. The anti-inflammatory activities are related to the modulation of nuclear factor kappa B in the reduction of inflammatory markers, such as tumor necrosis factor-alpha, C-reactive protein, and pro-inflammatory cytokines, as well as in the reduction of adhesion molecules in the wall of the vases.

CONCLUSION

The main phytochemicals present in cocoa and dark chocolates are catechins and their epicatechin isomers, which are responsible for improving inflammatory, metabolic, and antioxidant profiles. Its consumption can be encouraged, but with caution, owing to the caloric supply and forms of chocolate production, as these factors can reduce the presence of flavonoids in its composition.

RELEVANCE FOR PATIENTS

The antioxidant and anti-inflammatory functions of the phytochemicals in cocoa and dark chocolate are responsible for modulating nitric oxide via activation/phosphorylation and acting as a vasodilator. Reducing the formation of reactive oxygen species, as well as activating antioxidant enzymes. As for the anti-inflammatory activities, they modulate the nuclear factor kappa B, reducing inflammatory markers, thus improving the antioxidant and inflammatory profile of these patients.

The Role of Nutrition on Meta-inflammation: Insights and Potential Targets in Communicable and Chronic Disease Management

PURPOSE OF REVIEW

Chronic low-grade inflammation may contribute to the onset and progression of communicable and chronic diseases. This review examined the effects and eventual mediation roles of different nutritional factors on inflammation.

RECENT FINDINGS

Potential nutritional compounds influencing inflammation processes include macro and micronutrients, bioactive molecules (polyphenols), specific food components, and culinary ingredients as well as standardized dietary patterns, eating habits, and chrononutrition features. Therefore, research in this field is still required, taking into account critical aspects of heterogeneity including type of population, minimum and maximum intakes and adverse effects, cooking methods, physiopathological status, and times of intervention. Moreover, the integrative analysis of traditional variables (age, sex, metabolic profile, clinical history, body phenotype, habitual dietary intake, physical activity levels, and lifestyle) together with individualized issues (genetic background, epigenetic signatures, microbiota composition, gene expression profiles, and metabolomic fingerprints) may contribute to the knowledge and prescription of more personalized treatments aimed to improving the precision medical management of inflammation as well as the design of anti-inflammatory diets in chronic and communicable diseases.

Protective efficacy of dark chocolate in letrozole-induced ovary toxicity model rats: hormonal, biochemical, and histopathological investigation

OBJECTIVE

To assess the protective effect of dark chocolate (DC) on the letrozole-induced rat model of polycystic ovary syndrome (PCOS).

METHODS

In this experimental study, 32 female Wistar rats, weighing (200 ± 20) g, were randomly categorized into 4 groups including control, letrozole (1 mg·kg·d), metformin (500 mg·kg·d) along with letrozole, and DC (500 mg·kg·d) along with letrozole for 28 d by oral gavage. Twenty-four hours after the last supplementation, direct blood sampling was taken from the heart to obtain blood serum for evaluation of sex hormones and gonadotropins, oxidative parameters, inflammatory cytokines, and ovarian tissue was examined for histology.

RESULTS

The DC treatment significantly improved PCOS signs, as demonstrated by the significant restoration of ovarian morphology and physiological functions as compared with the letrozole group. DC treatment also decreased ovarian interleukin-1β and tumor necrosis factor-α levels and improved total oxidative/antioxidative status as compared with the letrozole group.

CONCLUSIONS

Treating the animals with DC could alleviate the PCOS symptoms and reduced the toxic effects of letrozole in the ovary. This effect may mediate through antioxidant and antiinflammatory properties.

Effect of Important Food Sources of Fructose-Containing Sugars on Inflammatory Biomarkers: A Systematic Review and Meta-Analysis of Controlled Feeding Trials

BACKGROUND

Fructose-containing sugars as sugar-sweetened beverages (SSBs) may increase inflammatory biomarkers. Whether this effect is mediated by the food matrix at different levels of energy is unknown. To investigate the role of food source and energy, we conducted a systematic review and meta-analysis of controlled trials on the effect of different food sources of fructose-containing sugars on inflammatory markers at different levels of energy control.

METHODS

MEDLINE, Embase, and the Cochrane Library were searched through March 2022 for controlled feeding trials ≥ 7 days. Four trial designs were prespecified by energy control: substitution (energy matched replacement of sugars); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced). The primary outcome was C-reactive protein (CRP). Secondary outcomes were tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Independent reviewers extracted data and assessed risk of bias. GRADE assessed certainty of evidence.

RESULTS

We identified 64 controlled trials (91 trial comparisons, n = 4094) assessing 12 food sources (SSB; sweetened dairy; sweetened dairy alternative [soy]; 100% fruit juice; fruit; dried fruit; mixed fruit forms; sweetened cereal grains and bars; sweets and desserts; added nutritive [caloric] sweetener; mixed sources [with SSBs]; and mixed sources [without SSBs]) at 4 levels of energy control over a median 6-weeks in predominantly healthy mixed weight or overweight/obese adults. Total fructose-containing sugars decreased CRP in addition trials and had no effect in substitution, subtraction or ad libitum trials. No effect was observed on other outcomes at any level of energy control. There was evidence of interaction/influence by food source: substitution trials (sweetened dairy alternative (soy) and 100% fruit juice decreased, and mixed sources (with SSBs) increased CRP); and addition trials (fruit decreased CRP and TNF-α; sweets and desserts (dark chocolate) decreased IL-6). The certainty of evidence was moderate-to-low for the majority of analyses.

CONCLUSIONS

Food source appears to mediate the effect of fructose-containing sugars on inflammatory markers over the short-to-medium term. The evidence provides good indication that mixed sources that contain SSBs increase CRP, while most other food sources have no effect with some sources (fruit, 100% fruit juice, sweetened soy beverage or dark chocolate) showing decreases, which may be dependent on energy control.

CLINICALTRIALS

gov: (NCT02716870).

Different Food Sources of Fructose-Containing Sugars and Fasting Blood Uric Acid Levels: A Systematic Review and Meta-Analysis of Controlled Feeding Trials

BACKGROUND

Although fructose as a source of excess calories increases uric acid, the effect of the food matrix is unclear.

OBJECTIVES

To assess the effects of fructose-containing sugars by food source at different levels of energy control on uric acid, we conducted a systematic review and meta-analysis of controlled trials.

METHODS

MEDLINE, Embase, and the Cochrane Library were searched (through 11 January 2021) for trials ≥ 7 days. We prespecified 4 trial designs by energy control: substitution (energy-matched replacement of sugars in diets); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced in diets) designs. Independent reviewers (≥2) extracted data and assessed the risk of bias. Grading of Recommendations, Assessment, Development, and Evaluation was used to assess the certainty of evidence.

RESULTS

We included 47 trials (85 comparisons; N = 2763) assessing 9 food sources [sugar-sweetened beverages (SSBs), sweetened dairy, fruit drinks, 100% fruit juice, fruit, dried fruit, sweets and desserts, added nutritive sweetener, and mixed sources] across 4 energy control levels in predominantly healthy, mixed-weight adults. Total fructose-containing sugars increased uric acid levels in substitution trials (mean difference, 0.16 mg/dL;  95% CI:  0.06-0.27 mg/dL;  P = 0.003), with no effect across the other energy control levels. There was evidence of an interaction by food source: SSBs and sweets and desserts increased uric acid levels in the substitution design, while SSBs increased and 100% fruit juice decreased uric acid levels in addition trials. The certainty of evidence was high for the increasing effect of SSBs in substitution and addition trials and the decreasing effect of 100% fruit juice in addition trials and was moderate to very low for all other comparisons.

CONCLUSIONS

Food source more than energy control appears to mediate the effects of fructose-containing sugars on uric acid. The available evidence provides reliable indications that SSBs increase and 100% fruit juice decreases uric acid levels. More high-quality trials of different food sources are needed. This trial was registered at clinicaltrials.gov as NCT02716870.

Anti-Inflammatory Properties of Diet: Role in Healthy Aging

Inflammation is a physiological process involved in the defenses of the body and the repair of tissues. It is acutely activated by infections, trauma, toxins, or allergic reactions. However, if it becomes chronic, inflammation can end up stimulating the development of diseases such as cardiovascular disease, autoimmune disease, neurological disease, or cancer. Additionally, during aging, inflammation becomes increasingly more chronic. Furthermore, we found that certain foods, such as saturated fats, have pro-inflammatory activity. Taking this into account, in this review we have discussed different diets with possible anti-inflammatory activity, the commonly ingested components of each diet and their active compounds. In addition, we have proposed some dietary guidelines, as well as a list of compounds present in foods with anti-inflammatory activity, outlining how to combine them to achieve optimal anti-inflammatory effects. Therefore, we can conclude that the compounds in our diet with anti-inflammatory activity could help alleviate the inflammatory processes derived from diseases and unhealthy diets, and thereby promote healthy aging.

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.

Effects of Interval Jump Rope Exercise Combined with Dark Chocolate Supplementation on Inflammatory Adipokine, Cytokine Concentrations, and Body Composition in Obese Adolescent Boys

We examined the effects of six weeks of dark chocolate supplementation combined with interval jump rope exercise (JRE) on inflammatory cytokines, adipokines, and body composition in obese adolescent boys. Forty-eight obese adolescent boys (age  = 15.4  ±  1.1 years and body mass index  =  32.2  ±  2.4 kg/m²) were randomly assigned into one of four groups: JRE + white chocolate (JW; n = 13), JRE + dark chocolate supplementation (JD; n = 13), dark chocolate supplementation (DS; n = 12), or control (C; n = 12). Participants in JW and JD groups performed JRE for three times per week for six weeks. Participants in the DS and JD groups consumed 30 g of dark chocolate containing 83% of cocoa. Body composition, pro-inflammatory cytokines ((hs-CRP, TNF-α, IL-6), adipokines (leptin, resistin, RBP-4, chemerin, MCP-1), and anti-inflammatory adipokines (irisin, adiponectin)) were evaluated prior to and after the intervention trials. All three intervention trials significantly (p < 0.05) decreased body mass, waist-hip ratio, fat mass, hs-CRP, TNF-α, IL-6, leptin, resistin, RBP-4, and MCP-1, and increased irisin and adiponectin concentrations. The improvements in these parameters were greater in the JD group, and additionally, chemerin concentrations decreased only in the JD group. JD enhanced adiponectin concentrations and decreased IL-6 concentrations compared to C. Moreover, JD significantly reduced chemerin concentrations, an effect not observed in any of the other interventions. We demonstrated that dark chocolate supplementation potentiated JRE-induced decreases in body mass, WHR, FM, hs-CRP, TNF-α, IL-6, leptin, resistin, RBP-4, and MCP-1, chemerin as well as increases irisin and adiponectin concentrations in obese adolescent boys. Therefore, JRE combined with dark chocolate supplementation could be a beneficial in reducing obesity-induced inflammation in adolescent boys.

The sweet side of dark chocolate for chronic kidney disease patients

Chocolate is a widely appreciated foodstuff with historical appreciation as a food from the gods. In addition to its highly palatable taste, it is a rich source of (poly)phenolics, which have several proposed salutogenic effects, including neuroprotective anti-inflammatory, anti-oxidant and cardioprotective capabilities. Despite the known benefits of this ancient foodstuff, there is a paucity of information on the effects of chocolate in the context of chronic kidney disease (CKD). This review focusses on the potential salutogenic contribution of chocolate intake, to mitigate inflammatory and oxidative burden in CKD, its potential, for cardiovascular protection and on the maintenance of diversity in gut microbiota, as well as clinical perspectives, on regular chocolate intake by CKD patients.

Effects of Adenovirus-Mediated Overexpression of JAZF1 on Chronic Inflammation: An In Vitro and In Vivo Study

BACKGROUND Insulin sensitivity and inflammation can be affected by juxtaposition with another zinc finger gene 1 (JAZF1), but its precise role in chronic inflammation is unclear. In this study, JAZF1-overexpression adenovirus plasmids were transfected into macrophages, CD4⁺ T cells, and C57BL/6J mice to assess the role of JAZF1 in chronic inflammation. MATERIAL AND METHODS JAZF1 was cloned into an adenovirus skeleton plasmid and transfected in HEK293 cells to package and enrich the virus particles. In vitro, the JAZF1 overexpression adenovirus vector (PAD-JAZF1) was cultured with peritoneal macrophages and peripheral blood CD4⁺ T cells of C57BL/6J mice, and samples were evaluated using flow cytometry. In vivo, PAD-JAZF1 was introduced into C57BL/6J mice, and livers were collected to evaluate factors related to inflammation by hematoxylin & eosin and immunohistochemical staining. RESULTS In vitro, PAD-JAZF1 decreased total macrophages, CD11c⁺ macrophages, and the secretion of proinflammatory cytokines, but increased CD206⁺ macrophages. It also decreased total CD4⁺T cells, active T cells, memory T cells, and the secretion of IL-6, IL-10, and IFN-γ, but increased Treg cells and restrictive T cells. In vivo, compared to those in the control group transfected with the adenovirus skeleton vector, mice transfected with the PAD-JAZF1 recombinant adenovirus had fewer CD11c⁺ ATMs and CD4⁺ T cells, lower levels of TNF-alpha and IL-6, and higher IL-10 concentrations in the liver. CONCLUSIONS These findings indicate that JAZF1 limits chronic inflammation by reducing macrophage and CD4⁺T cell populations, altering subtype differentiation, and regulating the secretion of immune-related factors.