Cocoa Consumption and Blood Pressure in Middle-Aged and Elderly Subjects: a Meta-Analysis

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.

Extracellular vesicles and their effect on vascular haemodynamics: a systematic review

Extracellular vesicles (EVs) are released from all cell types studied to date and act as intercellular communicators containing proteins, nucleic acids and lipid cargos. They have been shown to be involved in maintaining homoeostasis as well as playing a role in the development of pathology including hypertension and cardiovascular disease. It is estimated that there is 109-1010 circulating EVs/mL in the plasma of healthy individuals derived from various sources. While the effect of EVs on vascular haemodynamic parameters will be dependent on the details of the model studied, we systematically searched and summarized current literature to find patterns in how exogenously injected EVs affected vascular haemodynamics. Under homoeostatic conditions, evidence from wire and pressure myography data demonstrate that injecting isolated EVs derived from cell types found in blood and blood vessels resulted in the impairment of vasodilation in blood vessels ex vivo. Impaired vasodilation was also observed in rodents receiving intravenous injections of human plasma EVs from cardiovascular diseases including valvular heart disease, acute coronary syndrome, myocardial infarction and end stage renal disease. When EVs were derived from models of metabolic syndromes, such as diabetes, these EVs enhanced vasoconstriction responses in blood vessels ex vivo. There were fewer publications that assessed the effect of EVs in anaesthetised or conscious animals to confirm whether effects on the vasculature observed in ex vivo studies translated into alterations in vascular haemodynamics in vivo. In the available conscious animal studies, the in vivo data did not always align with the ex vivo data. This highlights the importance of in vivo work to determine the effects of EVs on the integrative vascular haemodynamics.

AI-based preeclampsia detection and prediction with electrocardiogram data

Introduction

More than 76,000 women die yearly from preeclampsia and hypertensive disorders of pregnancy. Early diagnosis and management of preeclampsia can improve outcomes for both mother and baby. In this study, we developed artificial intelligence models to detect and predict preeclampsia from electrocardiograms (ECGs) in point-of-care settings.

Methods

Ten-second 12-lead ECG data was obtained from two large health care settings: University of Tennessee Health Science Center (UTHSC) and Atrium Health Wake Forest Baptist (AHWFB). UTHSC data was split into 80% training and 20% holdout data. The model used a modified ResNet convolutional neural network, taking one-dimensional raw ECG signals comprising 12 channels as an input, to predict risk of preeclampsia. Sub-analyses were performed to assess the predictive accuracy for preeclampsia prediction within 30, 60, or 90 days before diagnosis.

Results

The UTHSC cohort included 904 ECGs from 759 females (78.8% African American) with a mean ± sd age of 27.3 ± 5.0 years. The AHWFB cohort included 817 ECGs from 141 females (45.4 African American) with a mean ± sd age of 27.4 ± 5.9 years. The cross-validated ECG-AI model yielded an AUC (95% CI) of 0.85 (0.77-0.93) on UTHSC holdout data, and an AUC (95% CI) of 0.81 (0.77-0.84) on AHWFB data. The sub-analysis of different time windows before preeclampsia prediction resulted in AUCs (95% CI) of 0.92 (0.84-1.00), 0.89 (0.81-0.98) and 0.90 (0.81-0.98) when tested on ECGs 30 days, 60 days and 90 days, respectively, before diagnosis. When assessed on early onset preeclampsia (preeclampsia diagnosed at <34 weeks of pregnancy), the model's AUC (95% CI) was 0.98 (0.89-1.00).

Discussion

We conclude that preeclampsia can be identified with high accuracy via application of AI models to ECG data.

Perspectives on pregnant women's educational needs to prevent TB complications during pregnancy and the neonatal period. A qualitative study

BACKGROUND

Tuberculosis (TB) during pregnancy could confer a high risk for maternal and infant morbidity. Literature indicates that the global burden of active TB disease among pregnant women is not well researched. Statistics for South Africa from WHO give an estimated incidence of 360, 000 cases of TB in 2019; 14,000 people became ill with multidrug-resistant TB in 2019, with a rate of 615 per 100,000 population, implying that the cohorts included pregnant women with and without a diagnosis of TB infection. Therefore, the study aims to increase the understanding of the educational needs required to prevent TB complications during pregnancy and the neonatal period in women diagnosed with TB infection.

METHODS

The study used cross-sectional qualitative and descriptive designs to collect data in the clinical setting of the primary health care services of Limpopo Province, South Africa. The population comprised pregnant women diagnosed with TB infection. A non-probability purposive sampling technique was used to sample 2 health centers and 5 clinics in each of the three sampled districts. The targeted sample size was 63 and it was achieved even though data saturation was observed. Individual interviews were conducted, audiotaped, and transcribed. Guided by the study questions, a thematic content analysis of the findings was used. Ethical considerations were also observed.

RESULTS

Despite that pregnant women have general knowledge about TB disease, the knowledge and awareness regarding the prevention of TB complications in pregnancy and the neonatal period, information on TB/HIV and COVID-19 co-infections, and participants' knowledge about other non-infectious diseases that may affect the mother with TB infection and foetus showed a deficit.

CONCLUSION

Pregnant women with TB disease need to be educated on the negative effects of non-adherence to TB treatment during pregnancy and the neonatal period. There is a need to educate pregnant women about the variant signs and symptoms of TB, HIV and COVID-19 infections since there is a misconception that the three diseases are similar. It is important that pregnant mothers diagnosed with TB should start treatment as soon as possible.

Cocoa Shell Extract Reduces Blood Pressure in Aged Hypertensive Rats via the Cardiovascular Upregulation of Endothelial Nitric Oxide Synthase and Nuclear Factor (Erythroid-Derived 2)-like 2 Protein Expression

Cocoa shell is a by-product of cocoa manufacturing. We obtained an aqueous extract (CSE) rich in polyphenols and methylxanthines with antioxidant and vasodilatory properties. We aimed to evaluate the effects of CSE supplementation in aged hypertensive rats on blood pressure and the mechanism implicated. Eighteen-month-old male and female rats exposed to undernutrition during the fetal period who developed hypertension, with a milder form in females, were used (MUN rats). Systolic blood pressure (SBP; tail-cuff plethysmography) and a blood sample were obtained before (basal) and after CSE supplementation (250 mg/kg; 2 weeks, 5 days/week). Plasma SOD, catalase activity, GSH, carbonyls, and lipid peroxidation were assessed (spectrophotometry). In hearts and aortas from supplemented and non-supplemented age-matched rats, we evaluated the protein expression of SOD-2, catalase, HO-1, UCP-2, total and phosphorylated Nrf2 and e-NOS (Western blot), and aorta media thickness (confocal microscopy). MUN males had higher SBP compared with females, which was reduced via CSE supplementation with a significant difference for group, sex, and interaction effect. After supplementation with plasma, GSH, but not catalase or SOD, was elevated in males and females. Compared with non-supplemented rats, CSE-supplemented males and females exhibited increased aorta e-NOS and Nrf2 protein expression and cardiac phosphorylated-Nrf2, without changes in SOD-2, catalase, HO-1, or UCP-2 in cardiovascular tissues or aorta remodeling. In conclusion, CSE supplementation induces antihypertensive actions related to the upregulation of e-NOS and Nrf2 expression and GSH elevation and a possible direct antioxidant effect of CSE bioactive components. Two weeks of supplementation may be insufficient to increase antioxidant enzyme expression.

From Cocoa to Chocolate: Effect of Processing on Flavanols and Methylxanthines and Their Mechanisms of Action

Despite the health benefits associated with the ingestion of the bioactive compounds in cocoa, the high concentrations of polyphenols and methylxanthines in the raw cocoa beans negatively influence the taste, confer the astringency and bitterness, and affect the stability and digestibility of the cocoa products. It is, therefore, necessary to process cocoa beans to develop the characteristic color, taste, and flavor, and reduce the astringency and bitterness, which are desirable in cocoa products. Processing, however, affects the composition and quantities of the bioactive compounds, resulting in the modification of the health-promoting properties of cocoa beans and chocolate. In this advanced review, we sought to better understand the effect of cocoa's transformational process into chocolate on polyphenols and methylxanthine and the mechanism of action of the original flavanols and methylxanthines. More data on the cocoa processing effect on cocoa bioactives are still needed for better understanding the effect of each processing step on the final polyphenolic and methylxanthine composition of chocolate and other cocoa products. Regarding the mechanisms of action, theobromine acts through the modulation of the fatty acid metabolism, mitochondrial function, and energy metabolism pathways, while flavanols mainly act though the protein kinases and antioxidant pathways. Both flavanols and theobromine seem to be involved in the nitric oxide and neurotrophin regulation.

Bioactivities and mechanisms of dietary proanthocyanidins on blood pressure lowering: A critical review of in vivo and clinical studies

Proanthocyanidins, widespread in natural plant sources, are bioactive substances that exhibit broad benefits to human health. Of note, proanthocyanidins have been reported to lower blood pressure and prevent hypertension, but a critical review of this is lacking. In this review, information on the basic structures and absorption of dietary proanthocyanidins as well as their bioactivities and related mechanisms on the lowering of blood pressure derived via in vivo and clinical studies are summarized. Clinical studies have shown that proanthocyanidins have a pronounced blood pressure-lowering effect, effectively preventing hypertension and reducing the occurrence of cardiovascular and cerebrovascular diseases. The potential mechanisms, which are herein reviewed in detail, involve the improvement of vascular function, reduction of oxidative stress and inflammation, and modulation of lipid metabolism. Taken together, this work provides information for a better understanding of the antihypertensive effects of proanthocyanidins, which may promote their use to reduce the risk of developing hypertension.

Polyphenols–Gut–Heart: An Impactful Relationship to Improve Cardiovascular Diseases

A healthy gut provides the perfect habitat for trillions of bacteria, called the intestinal microbiota, which is greatly responsive to the long-term diet; it exists in a symbiotic relationship with the host and provides circulating metabolites, hormones, and cytokines necessary for human metabolism. The gut–heart axis is a novel emerging concept based on the accumulating evidence that a perturbed gut microbiota, called dysbiosis, plays a role as a risk factor in the pathogenesis of cardiovascular disease. Consequently, recovery of the gut microbiota composition and function could represent a potential new avenue for improving patient outcomes. Despite their low absorption, preclinical evidence indicates that polyphenols and their metabolites are transformed by intestinal bacteria and halt detrimental microbes’ colonization in the host. Moreover, their metabolites are potentially effective in human health due to antioxidant, anti-inflammatory, and anti-cancer effects. The aim of this review is to provide an overview of the causal role of gut dysbiosis in the pathogenesis of atherosclerosis, hypertension, and heart failure; to discuss the beneficial effects of polyphenols on the intestinal microbiota, and to hypothesize polyphenols or their derivatives as an opportunity to prevent and treat cardiovascular diseases by shaping gut eubiosis.

DISCOVID: discovering patterns of COVID-19 infection from recovered patients: a case study in Saudi Arabia

A respiratory syndrome COVID-19 pandemic has become a serious global concern. Still, a large number of people have been daily infected worldwide. Discovering COVID-19 infection patterns is significant for health providers towards understanding the infection factors. Current COVID-19 research works have not been attempted to discover the infection patterns, yet. In this paper, we employ an Association Rules Apriori (ARA) algorithm to discover the infection patterns from COVID-19 recovered patients’ data. A non-clinical COVID-19 dataset is introduced and analyzed. A sample of recovered patients’ data is manually collected in Saudi Arabia. Our manual computation and experimental results show strong associative rules with high confidence scores among males, weight above 70 kilograms, height above 160 centimeters, and fever patterns. These patterns are the strongest infection patterns discovered from COVID-19 recovered patients’ data.

Acute Effects of Cocoa Flavanols on Blood Pressure and Peripheral Vascular Reactivity in Type 2 Diabetes Mellitus and Essential Hypertension

Background: Type 2 diabetes mellitus (T2DM) is associated with a high risk of vascular complications. Interestingly, cocoa flavanols (CF) can exert beneficial vascular effects in non-diabetic subjects. However, these effects have only been scarcely studied in T2DM. Therefore, we performed a study to assess the effects on vascular reactivity of a single dose of CF (790 mg) in T2DM and whether certain antihypertensive drugs may modulate these effects. Methods: 24 non-diabetic and 11 T2DM subjects were studied in a cross-over design. Fasting blood samples, blood pressure (BP), and arterial vasoreactivity (flow-mediated dilation) were assessed before and 70 min after capsule ingestion. Muscle microvascular reactivity was only assessed after capsule ingestion. Age, waist-to-hip ratio, BP at baseline, and the use of antihypertensive drugs were regarded as covariates in a mixed models analysis. Results: CF ingestion did not affect any parameter. However, independent of the type of capsules ingested, a decrease in diastolic BP by 3 mmHg (95% CI: −4.0; −2.0) and an increase in the change in brachial artery diameter (pre vs. post occlusion) by 0.06 mm (95% CI: 0.01; 0.12) were detected in the non-diabetic group, while they remained unchanged in the T2DM group. Conclusion: No beneficial effects of CF were detected on vascular reactivity parameters in T2DM and non-diabetic participants.

Prospective associations between a priori dietary patterns adherence and kidney function in an elderly Mediterranean population at high cardiovascular risk

Purpose

To assess the association between three different a priori dietary patterns adherence (17-item energy reduced-Mediterranean Diet (MedDiet), Trichopoulou-MedDiet and Dietary Approach to Stop Hypertension (DASH)), as well as the Protein Diet Score and kidney function decline after one year of follow-up in elderly individuals with overweight/obesity and metabolic syndrome (MetS).

Methods

We prospectively analyzed 5675 participants (55–75 years) from the PREDIMED-Plus study. At baseline and at one year, we evaluated the creatinine-based estimated glomerular filtration rate (eGFR) and food-frequency questionnaires-derived dietary scores. Associations between four categories (decrease/maintenance and tertiles of increase) of each dietary pattern and changes in eGFR (ml/min/1.73m²) or ≥ 10% eGFR decline were assessed by fitting multivariable linear or logistic regression models, as appropriate.

Results

Participants in the highest tertile of increase in 17-item erMedDiet Score showed higher upward changes in eGFR (β: 1.87 ml/min/1.73m²; 95% CI: 1.00–2.73) and had lower odds of ≥ 10% eGFR decline (OR: 0.62; 95% CI: 0.47–0.82) compared to individuals in the decrease/maintenance category, while Trichopoulou-MedDiet and DASH Scores were not associated with any renal outcomes. Those in the highest tertile of increase in Protein Diet Score had greater downward changes in eGFR (β: − 0.87 ml/min/1.73m²; 95% CI: − 1.73 to − 0.01) and 32% higher odds of eGFR decline (OR: 1.32; 95% CI: 1.00–1.75).

Conclusions

Among elderly individuals with overweight/obesity and MetS, only higher upward change in the 17-item erMedDiet score adherence was associated with better kidney function after one year. However, increasing Protein Diet Score appeared to have an adverse impact on kidney health. Trial Registration Number: ISRCTN89898870 (Data of registration: 2014).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-022-02838-7.

The Effect of Dietary Polyphenols on Vascular Health and Hypertension: Current Evidence and Mechanisms of Action

The aim of this review was to explore existing evidence from studies conducted on humans and summarize the mechanisms of action of dietary polyphenols on vascular health, blood pressure and hypertension. There is evidence that some polyphenol-rich foods, including berry fruits rich in anthocyanins, cocoa and green tea rich in flavan-3-ols, almonds and pistachios rich in hydroxycinnamic acids, and soy products rich in isoflavones, are able to improve blood pressure levels. A variety of mechanisms can elucidate the observed effects. Some limitations of the evidence, including variability of polyphenol content in plant-derived foods and human absorption, difficulty disentangling the effects of polyphenols from other dietary compounds, and discrepancy of doses between animal and human studies should be taken into account. While no single food counteracts hypertension, adopting a plant-based dietary pattern including a variety of polyphenol-rich foods is an advisable practice to improve blood pressure.

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.

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.

Effect of proanthocyanidins on blood pressure: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Hypertension is a common chronic disease that can lead to serious health problems. Previous studies have not drawn a consistent conclusion about the effect of proanthocyanidins (PCs) on blood pressure (BP). This systematic review and meta-analysis aims to evaluate the effect of PCs supplementation on blood pressure (BP).

METHODS

A comprehensive literature search was performed in 6 databases (Pubmed, Scopus, ISI Web of Science, the Cochrane Library, Embase and Google Scholar) to identify the randomized controlled trials (RCTs) that evaluated the BP-lowering effect of PCs. Subgroup and sensitivity analyses were conducted to evaluate the potential heterogeneity. Meta-regression analysis was used to evaluate dose effects of PCs on BP.

RESULTS

A total of 6 studies comprising 376 subjects were included in our meta-analysis to estimate the pooled effect size. This meta-analysis suggested that PCs supplementation could significantly reduce systolic blood pressure (SBP) (WMD: -4.598 mmHg; 95 % CI: -8.037, -1.159; I² = 33.7 %; p = 0.009), diastolic blood pressure (DBP) (WMD: -2.750 mmHg; 95 % CI: -5.087, -0.412; I² = 0.0 %; p = 0.021) and mean arterial pressure (MAP) (WMD: -3.366 mmHg; 95 % CI: -6.719, -0.041 mmHg; I² = 0.0 %; p = 0.049), but had no significant effect on pulse pressure (PP) (WMD: -2.131 mmHg; 95 % CI: -6.292, 2.030; I² = 0.0 %; p = 0.315). When the studies were stratified according to the duration of the study, there was a significant reduction on SBP in the subset of the trials with <12 weeks of duration. On the contrary, there was a significant reduction on DBP in the subset of the trials with ≥12 weeks of duration. The Subgroup analysis by BMI indicated that a significant reduction on SBP for people with a higher BMI (BMI ≥ 25) and a significant reduction on DBP for people with a lower BMI (BMI < 25). Additional subgroup analysis revealed low-dose-PCs (<245 mg/day) could significantly reduce SBP, DBP and MAP. The meta-regression analyses did not indicate the dose effects of PCs on SBP, DBP, PP and MAP.

CONCLUSION

Based on the current findings, PCs supplementation may be a useful treatment of hypertensive patients as well as a preventive measure in the prehypertensive and healthy subjects. However, further investigation is needed to confirm these results.

Pleotropic Effects of Polyphenols in Cardiovascular System

Numerous epidemiological and clinical studies demonstrate the beneficial effects of naturally occurring, polyphenol supplementations, on cardiovascular system. The present review emphasizes on the risk factors associated with cardiovascular disorders (involving heart and blood vessels), and overview of preclinical and clinical trials on polyphenols for the treatment of cardiovascular diseases. The review collaborates PUBMED, Google Scholar and Research gate databases, which were explored using keywords and their combinations such as polyphenols, cardiovascular disease, flavonoids, atherosclerosis, cardiovascular risk factors and several others, to create an eclectic manuscript. The potency and efficacy of these polyphenols are mainly depending upon the amount of consumption and bioavailability. Recent data showed that polyphenols also exert beneficial actions on vascular system by blocking platelet aggregation and oxidation of low-density lipoprotein (LDL), ameliorating endothelial dysfunction, reducing blood pressure, improving antioxidant defenses and alleviating inflammatory responses. Several studies evidently support the cardioprotective actions mediated by polyphenols, however, some studies or long-term follow-up of human studies, did not demonstrate decisive outcomes because of variations in dose regimen and lack of appropriate controls. Therefore, more data is required to explore the therapeutic benefits of bioactive compounds as a preventive therapy for CVDs.

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.