The effect of cocoa/dark chocolate consumption on lipid profile, glycemia, and blood pressure in diabetic patients: A meta-analysis of observational studies

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.

Assessing the Impact of (Poly)phenol-Rich Foods on Cardiometabolic Risk in Postmenopausal Women: A Dietary Trial

Menopause is a critical stage in a woman's life in which cardiometabolic alterations appear, such as insulin resistance or a predisposition to visceral fat deposits, leading to an increased risk of cardiometabolic diseases (R-CMBs). New strategies to reduce the R-CMBs in postmenopausal women using natural compounds without adverse effects are desirable. In this sense, plant-based diets rich in fruits and vegetables could play a fundamental role due to the high content of bioactive compounds found in these diets, such as (poly)phenols, known for their antioxidant, anti-inflammatory and vasodilator properties. The aim of this research was to carry out a dietary trial to evaluate the effect of the daily intake of different (poly)phenol-rich foods (PP-rich foods) for 2 months on the modulation of the main cardiometabolic risk biomarkers of postmenopausal women. The results showed a slight improvement in blood pressure (BP), lipid profile and oxidative stress, endothelial function and inflammatory biomarkers. These findings suggest that daily consumption of PP-rich foods alleviated the R-CMBs of postmenopausal women by reducing the oxidative stress and, thus, the risk of cardiovascular events; however, the magnitude of the cardioprotective effect of (poly)phenols depends on inter-individual variability.

Dietary patterns suggest that dark chocolate intake may have an inhibitory effect on oral cancer: a Mendelian randomization study

Background

Previous studies reported that variations in dietary intake patterns substantially impact human health, specifically tumorigenesis. However, confounding factors in previous cohort studies have obscured the relationship between dietary differences and the risk of oral cancer (OC).

Materials and methods

We developed an outcome dataset from genome-wide association studies (GWAS) data on three OCs within the GAME-ON project, using GWAS-META merging. We extracted 21 dietary exposures, including 10 dietary patterns, 6 vitamins, and 5 micronutrients, from the UK Biobank database, using the inverse variance weighting method as the primary statistical method. Sensitivity analysis was conducted to detect heterogeneity and pleiotropy. Serum metabolite concentrations were adjusted using multivariate Mendelian randomization.

Results

Of the 10 analyzed dietary patterns, 8 showed no significant association with the risk of developing OC. Consumption of dark chocolate (inverse variance weighted [IVW]: Odds ratio (OR) = 0.786, 95% confidence interval [CI]: 0.622-0.993, p = 0.044) and sweet pepper exhibited an inverse relationship with OC risk (IVW: OR = 0.757, 95% CI: 0.574-0.997, p = 0.048). Reverse MR analysis revealed no reverse causality. Furthermore, no significant correlation was observed between the intake of 6 vitamins and 5 micronutrients and the risk of developing OC. After using multivariable MR to adjust for serum caffeine, linoleate, theophylline, and theobromine metabolism levels, consuming dark chocolate was unrelated to a decreased risk of OC. After adjusting each serum metabolite individually, the observed p-values deviated from the original values to varying degrees, indicating that the components of dark chocolate could have different effects. Among these components, theophylline demonstrated the most significant inhibitory effect.

Conclusion

This study demonstrated a causal relationship between the intake of dark chocolate and sweet peppers and a lower risk of OC. The components of dark chocolate could have different effects.

Microencapsulation of Theobroma cacao L polyphenols: A high-value approach with in vitro anti-Trypanosoma cruzi, immunomodulatory and antioxidant activities

Chagas disease (CHD) is the highest economic burden parasitosis worldwide and the most important cardiac infection, without therapeutic alternatives to halt or reverse its progression. In CHD-experimental models, antioxidant and anti-inflammatory compounds have demonstrated therapeutic potential in cardiac dysfunction. Theobroma cacao polyphenols are potent natural antioxidants with cardioprotective and anti-inflammatory action, which are susceptible to degradation, requiring technological approaches to guarantee their protection, stability, and controlled release. Here, 21 cocoa polyphenol-rich microencapsulates were produced by spray-drying and freeze-drying techniques using two wall materials (maltodextrin and gum arabic). Chemical (total and individual phenolic content and antioxidant activity), structural (morphology), and biological parameters (cytotoxicity, trypanocidal, antioxidant, and immunomodulatory activities) were assessed to determine the most efficient microencapsulation conditions on Trypanosoma cruzi-infected myocardioblast and macrophage cells. Significant antiproliferative properties against infected cells (superior to benznidazole) were found in two microencapsulates which also exhibited cardioprotective properties against oxidative stress, inflammation, and cell death.

In Vitro and In Vivo Evaluation of Dark Chocolate as Age-appropriate Oral Matrix

Swallowing difficulties encountered by geriatric patients who undergo polypharmacy represent a significant challenge that hampers patient compliance and therapeutic management. As an appealing and sensory-pleasing, chocolate-based formulations have emerged as a potential alternative oral dosage form suitable for both the elderly and paediatric populations. However, the extent to which the incorporation of drugs into a chocolate matrix affects their oral availability remains unclear. Therefore, the objective of this investigation was to explore the in vitro and in vivo performance of an ibuprofen-based chocolate dosage form. A matrix based on dark chocolate and the model drug was prepared at two distinct temperatures: 50 and 80 °C. In vitro release studies revealed that ibuprofen formulated through co-melting at 80 °C exhibited a statistically significant slower drug release (p < 0.05) compared to formulations prepared at 50 °C in both FaSSGF (fasted-state simulated gastric fluid) and lipolysis media. The enzymatic degradation of chocolate in the presence of lipase accelerated in vitro ibuprofen release from chocolate matrices. To delve deeper into the bioavailability of ibuprofen within the chocolate formulations, we conducted an in vivo assessment, comparing the pharmacokinetic profiles of ibuprofen in its conventional suspension form with our chocolate-based dosage forms. A notable drop (p < 0.05) in the maximum serum concentration of ibuprofen when incorporated into co-melted or solid-suspension chocolate matrices. However, no significant differences in plasma exposure were observed between the two formulations. These findings shed a light on the potential of chocolate to extend of ibuprofen when integrated into various chocolate matrices, showcasing the potential held by these innovative formulations.

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.

Cocoa seeds and chocolate products interaction with gut microbiota; mining microbial and functional biomarkers from mechanistic studies, clinical trials and 16S rRNA amplicon sequencing

In recent years, gut microbiome has evolved as a focal point of interest with growing recognition that a well-balanced gut microbiota is highly relevant to an individual's health status. The present review provides a mechanistic insight on the effects of cocoa chemicals on the gut microbiome and further reveals in silico biomarkers, taxonomic and functional features that distinguish gut microbiome of cocoa consumers and controls by using 16S rRNA gene sequencing data. The polyphenols in cocoa can change the gut microbiota either by inhibiting the growth of pathogenic bacteria in the gut such as Clostridium perfringens or by increasing the growth of beneficial microbiota in the gut such as Lactobacillus and Bifidobacterium. This paper demonstrates the holistic effect of gut microbiota on cocoa chemicals and how it impacts human health. We present herein the first comprehensive review and analysis of how raw and roasted cocoa and its products can specifically influence gut homeostasis, and likewise, how microbiota metabolizes cocoa chemicals. In addition to that, our 16S rRNA amplicon sequencing analysis revealed that the flavone and flavonols metabolism, aminobenzoate degradation and fatty acid elongation pathways represent the three most important signatures of microbial functions associated with cocoa consumption.

Hormetic response to B-type procyanidin ingestion involves stress-related neuromodulation via the gut-brain axis: Preclinical and clinical observations

B-type procyanidins, a series of catechin oligomers, are among the most ingested polyphenols in the human diet. Results of meta-analyses have suggested that intake of B-type procyanidins reduces cardiovascular disease risk. Another recent focus has been on the effects of B-type procyanidins on central nervous system (CNS) function. Although long-term B-type procyanidin ingestion is linked to health benefits, a single oral intake has been reported to cause physiological alterations in circulation, metabolism, and the CNS. Comprehensive analyses of previous reports indicate an optimal mid-range dose for the hemodynamic effects of B-type procyanidins, with null responses at lower or higher doses, suggesting hormesis. Indeed, polyphenols, including B-type procyanidins, elicit hormetic responses in vitro, but animal and clinical studies are limited. Hormesis of hemodynamic and metabolic responses to B-type procyanidins was recently confirmed in animal studies, however, and our work has linked these effects to the CNS. Here, we evaluate the hormetic response elicited by B-type procyanidins, recontextualizing the results of intervention trials. In addition, we discuss the possibility that this hormetic response to B-type procyanidins arises via CNS neurotransmitter receptors. We have verified the direction of future research for B-type procyanidins in this review.

Associations between vitamin D status and sight threatening and non-sight threatening diabetic retinopathy: a systematic review and meta-analysis

Background

Vitamin D levels have been shown to be associated with diabetic retinopathy, however to date, no review has examined the relationship between vitamin D and sight threatening diabetic retinopathy (STDR) and non-sight threatening diabetic retinopathy (NSTDR). The aim of this review, therefore, was to pool associations between vitamin D deficiency (25(OH)D < 20 ng/mL) and STDR/NSTDR. A further aim was to examine associations between circulating 25(OH)D levels and STDR/NSTDR.

Methods

A systematic review of major databases was undertaken for studies published from inception to 22/04/2022, using a pre-published protocol. Studies reporting prevalence of STDR or NSTDR versus a control group with diabetes and no DR or DME and either (a) vitamin D deficiency prevalence, or (b) circulating 25(OH)D levels, were included. A random effects meta-analysis was undertaken.

Results

Following screening, 12 studies (n = 9057) were included in the meta-analysis. STDR was significantly associated with vitamin D deficiency (OR = 1.80 95%CI 1.40-2.30; p = <0.001), whereas NSTDR was not (OR = 1.07 95%CI 0.90-1.27; p = 0.48). Both conclusions were graded as low credibility of evidence. Furthermore, circulating 25(OH)D levels were significantly associated with both NSTDR (SMD = -0.27 95%CI -0.50; -0.04; p = 0.02) and STDR (SMD = -0.49 95%CI -0.90; -0.07; p = 0.02), although these were graded as low credibility of evidence.

Conclusion

Vitamin D deficiency is significantly associated with STDR (including DME), but not with NSTDR. Given the well-reported associations between vitamin D deficiency and other unfavourable outcomes, it is important that vitamin D deficiency is managed appropriately and in a timely manner to reduce the risk of blindness in people with diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01059-3.

Hypertension and Dyslipidemia Combined Therapeutic Approaches

Treating blood pressure (BP) alone may provide only limited benefits while it is recommendable to manage the total cardiovascular risk. To date, several studies have shown that concomitant treatment of hypertension and dyslipidemia with non-pharmacological approaches and/or metabolically neutral antihypertensive drugs and statins produce a significantly greater reduction of the risk of developing cardiovascular disease. Thus, in this review article, we summarize the available evidence regarding non-pharmacological and pharmacological approaches with a favourable effect on both BP and lipids.