Effect of cocoa on blood pressure Ried, Karin; Fakler, Peter; Stocks, Nigel P ...
Cochrane database of systematic reviews,
04/2017, Letnik:
2017, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Background
High blood pressure is an important risk factor for cardiovascular disease, contributing to about 50% of cardiovascular events worldwide and 37% of cardiovascular‐related deaths in Western ...populations. Epidemiological studies suggest that cocoa‐rich products reduce the risk of cardiovascular disease. Flavanols found in cocoa have been shown to increase the formation of endothelial nitric oxide which promotes vasodilation and therefore blood pressure reduction. Here we update previous meta‐analyses on the effect of cocoa on blood pressure.
Objectives
To assess the effects on blood pressure of chocolate or cocoa products versus low‐flavanol products or placebo in adults with or without hypertension when consumed for two weeks or longer.
Search methods
This is an updated version of the review initially published in 2012. In this updated version, we searched the following electronic databases from inception to November 2016: Cochrane Hypertension Group Specialised Register, CENTRAL, MEDLINE and Embase. We also searched international trial registries, and the reference lists of review articles and included trials.
Selection criteria
Randomised controlled trials (RCTs) investigating the effects of chocolate or cocoa products on systolic and diastolic blood pressure in adults for a minimum of two weeks duration.
Data collection and analysis
Two review authors independently extracted data and assessed the risks of bias in each trial. We conducted random‐effects meta‐analyses on the included studies using Review Manager 5. We explored heterogeneity with subgroup analyses by baseline blood pressure, flavanol content of control group, blinding, age and duration. Sensitivity analyses explored the influence of unusual study design.
Main results
Thirty‐five trials (including 40 treatment comparisons) met the inclusion criteria. Of these, we added 17 trials (20 treatment comparisons) to the 18 trials (20 treatment comparisons) in the previous version of this updated review.
Trials provided participants with 30 to 1218 mg of flavanols (mean = 670 mg) in 1.4 to 105 grams of cocoa products per day in the active intervention group. The control group received either a flavanol‐free product (n = 26 treatment comparisons) or a low‐flavanol‐containing cocoa powder (range 6.4 to 88 mg flavanols (mean = 55 mg, 13 treatment comparisons; 259 mg, 1 trial).
Meta‐analyses of the 40 treatment comparisons involving 1804 mainly healthy participants revealed a small but statistically significant blood pressure‐reducing effect of flavanol‐rich cocoa products compared with control in trials of two to 18 weeks duration (mean nine weeks):
Mean difference systolic blood pressure (SBP) (95% confidence interval (CI): ‐1.76 (‐3.09 to ‐0.43) mmHg, P = 0.009, n = 40 treatment comparisons, 1804 participants;
Mean difference diastolic blood pressure (DBP) (95% CI): ‐1.76 (‐2.57 to ‐0.94) mmHg, P < 0.001, n = 39 treatment comparisons, 1772 participants.
Baseline blood pressure may play a role in the effect of cocoa on blood pressure. While systolic blood pressure was reduced significantly by 4 mmHg in hypertensive people (n = 9 treatment comparisons, 401 participants), and tended to be lowered in prehypertensive people (n= 8 treatment comparisons, 340 participants), there was no significant difference in normotensive people (n = 23 treatment comparisons, 1063 participants); however, the test for subgroup differences was of borderline significance (P = 0.08; I2 = 60%), requiring further research to confirm the findings.
Subgroup meta‐analysis by blinding suggested a trend towards greater blood pressure reduction in unblinded trials compared to double‐blinded trials, albeit statistically not significant. Further research is needed to confirm whether participant expectation may influence blood pressure results. Subgroup analysis by type of control (flavanol‐free versus low‐flavanol control) did not reveal a significant difference.
Whether the age of participants plays a role in the effect of cocoa on blood pressure, with younger participants responding with greater blood pressure reduction, needs to be further investigated.
Sensitivity analysis excluding trials with authors employed by trials sponsoring industry (33 trials, 1482 participants) revealed a small reduction in effect size, indicating some reporting bias.
Due to the remaining heterogeneity, which we could not explain in terms of blinding, flavanol content of the control groups, age of participants, or study duration, we downgraded the quality of the evidence from high to moderate.
Results of subgroup analyses should be interpreted with caution and need to be confirmed or refuted in trials using direct randomised comparisons.
Generally, cocoa products were highly tolerable, with adverse effects including gastrointestinal complaints and nausea being reported by 1% of participants in the active cocoa intervention group and 0.4% of participants in the control groups (moderate‐quality evidence).
Authors' conclusions
This review provides moderate‐quality evidence that flavanol‐rich chocolate and cocoa products cause a small (2 mmHg) blood pressure‐lowering effect in mainly healthy adults in the short term.
These findings are limited by the heterogeneity between trials, which could not be explained by prespecified subgroup analyses, including blinding, flavanol content of the control groups, age of participants, or study duration. However, baseline blood pressure may play a role in the effect of cocoa on blood pressure; subgroup analysis of trials with (pre)hypertensive participants revealed a greater blood pressure‐reducing effect of cocoa compared to normotensive participants with borderline significance.
Long‐term trials investigating the effect of cocoa on clinical outcomes are also needed to assess whether cocoa has an effect on cardiovascular events and to assess potential adverse effects associated with chronic ingestion of cocoa products.
Quality of life (QoL) is multi-dimensional concept of an individual' general well-being status in relation to their value, environment, cultural and social context in which they live. This study ...aimed to quantitatively synthesise available evidence on the association between QoL and mortality in the general population.
An electronic search was conducted using three bibliographic databases, MEDLINE, EMBASE and PsycINFO. Inclusion criteria were studies that assessed QoL using standardized tools and examined mortality risk in a non-patient population. Qualitative data synthesis and meta-analyses using a random-effects model were performed.
Of 4184 articles identified, 47 were eligible for inclusion, involving approximately 1,200,000 participants. Studies were highly heterogeneous in terms of QoL measures, population characteristics and data analysis. In total, 43 studies (91.5%) reported that better QoL was associated with lower mortality risk. The results of four meta-analyses indicated that higher health-related QoL (HRQoL) is associated with lower mortality risk, which was consistent for overall HRQoL (HR 0.633, 95% CI: 0.514 to 0.780), physical function (HR 0.987, 95% CI: 0.982 to 0.992), physical component score (OR 0.950, 95% CI: 0.935 to 0.965), and mental component score (OR 0.980, 95% CI: 0.969 to 0.992).
These findings provide evidence that better QoL/HRQoL was associated with lower mortality risk. The utility of these measures in predicting mortality risk indicates that they should be considered further as potential screening tools in general clinical practice, beyond the traditional objective measures such as body mass index and the results of laboratory tests.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Dark chocolate and flavanol-rich cocoa products have attracted interest as an alternative treatment option for hypertension, a known risk factor for cardiovascular disease. Previous meta-analyses ...concluded that cocoa-rich foods may reduce blood pressure. Recently, several additional trials have been conducted with conflicting results. Our study summarises current evidence on the effect of flavanol-rich cocoa products on blood pressure in hypertensive and normotensive individuals.
We searched Medline, Cochrane and international trial registries between 1955 and 2009 for randomised controlled trials investigating the effect of cocoa as food or drink compared with placebo on systolic and diastolic blood pressure (SBP/DBP) for a minimum duration of 2 weeks. We conducted random effects meta-analysis of all studies fitting the inclusion criteria, as well as subgroup analysis by baseline blood pressure (hypertensive/normotensive). Meta-regression analysis explored the association between type of treatment, dosage, duration or baseline blood pressure and blood pressure outcome. Statistical significance was set at P < 0.05.
Fifteen trial arms of 13 assessed studies met the inclusion criteria. Pooled meta-analysis of all trials revealed a significant blood pressure-reducing effect of cocoa-chocolate compared with control (mean BP change +/- SE: SBP: -3.2 +/- 1.9 mmHg, P = 0.001; DBP: -2.0 +/- 1.3 mmHg, P = 0.003). However, subgroup meta-analysis was significant only for the hypertensive or prehypertensive subgroups (SBP: -5.0 +/- 3.0 mmHg; P = 0.0009; DBP: -2.7 +/- 2.2 mm Hg, P = 0.01), while BP was not significantly reduced in the normotensive subgroups (SBP: -1.6 +/- 2.3 mmHg, P = 0.17; DBP: -1.3 +/- 1.6 mmHg, P = 0.12). Nine trials used chocolate containing 50% to 70% cocoa compared with white chocolate or other cocoa-free controls, while six trials compared high- with low-flavanol cocoa products. Daily flavanol dosages ranged from 30 mg to 1000 mg in the active treatment groups, and interventions ran for 2 to 18 weeks. Meta-regression analysis found study design and type of control to be borderline significant but possibly indirect predictors for blood pressure outcome.
Our meta-analysis suggests that dark chocolate is superior to placebo in reducing systolic hypertension or diastolic prehypertension. Flavanol-rich chocolate did not significantly reduce mean blood pressure below 140 mmHg systolic or 80 mmHg diastolic.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Suprathreshold Stochastic Resonance behind Cancer Rodrigo, Guillermo; Stocks, Nigel G.
Trends in biochemical sciences (Amsterdam. Regular ed.),
July 2018, 2018-07-00, 20180701, Letnik:
43, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Noise in gene expression is pervasive and, in some cases, even fulfills a functional role. Cancer cell populations exploit noise to increase heterogeneity as a defense against therapies. What lies ...behind this picture is a phenomenon of stochastic resonance led by the collective, rather than by individual cells.
In Australia, a herpes zoster (HZ) vaccination program targeting adults aged 70 years old with catch-up for those 71-79 years began in November 2016 but there is limited information on vaccine uptake ...and coverage achieved since commencement.
We used a national de-identified electronic primary care dataset, MedicineInsight, and extracted records from patients turning 50–90 years old during 2016–2018. Among patients considered regular attenders, with at least one visit per year in the two years prior, we estimated the crude and adjusted average monthly HZ vaccine uptake in the target population (70–79 years old) for each year since program implementation as well as cumulative vaccine coverage until December 2018. Multivariate logistic regression was used to analyse characteristics associated with higher coverage.
Among 52,229, 55,034, and 57,316 regular attenders turning 70–79 years old in 2016, 2017 and 2018 respectively, the average monthly vaccine uptake rate was 5.5%, 3.3%, and 1.6% respectively. Up to 31st December 2018, the estimated cumulative vaccine coverage in regularly attending adults was 46.9% (25,791/55,034). It was substantially lower at 41.6% (27,040/65,010) using an alternate definition of a regular attender. Vaccine coverage differed by sex (women: 48.5% versus men: 45.1%, adjusted OR = 1.1, 95% CI: 1.1–1.2); by jurisdiction (compared to New South Wales: 43.7%, South Australia: 55.6%, aOR = 1.6, 95% CI (1.5–1.8); Northern Territory: 27.6%, aOR = 0.6, (0.5–0.7)); by remoteness status (compared to major cities: 47.6%, remote/very remote areas: 38.2%, aOR = 0.7, (0.6–0.8)); and by socioeconomic disadvantage (compared to most disadvantaged: 41.8%, most advantaged: 48.6%, aOR = 1.6 (1.2–2.1)).
Our estimates of HZ vaccine coverage are substantially higher than the only other reports based on the Australian Immunisation Register however they still suggest that uptake is suboptimal. The use of electronic medical records can complement other data for estimating vaccine coverage in Australian adults.
In older persons without known cardiovascular disease, the use of low-dose aspirin resulted in a significantly higher risk of major hemorrhage and did not result in a significantly lower risk of ...cardiovascular disease than placebo.
A recent review concluded that general health checks fail to reduce mortality in adults.
This review focuses on general practice-based health checks and their effects on both surrogate and final ...outcomes.
Systematic search of PubMed, Embase, and the Cochrane Central Register of Controlled Trials.
Relevant data were extracted from randomised trials comparing the health outcomes of general practice-based health checks versus usual care in middle-aged populations.
Six trials were included. The end-point differences between the intervention and control arms in total cholesterol (TC), systolic and diastolic blood pressure (SBP, DBP), and body mass index (BMI) were -0.13 mmol/l (95% confidence interval CI = -0.19 to -0.07), -3.65 mmHg (95% CI = -6.50 to -0.81), -1.79 mmHg (95% CI = -2.93 to -0.64), and -0.45 kg/m(2) (95% CI = -0.66 to -0.24), respectively. The odds of a patient remaining at 'high risk' with elevated TC, SBP, DBP, BMI or continuing smoking were 0.63 (95% CI = 0.50 to 0.79), 0.59 (95% CI = 0.28 to 1.23), 0.63 (95% CI = 0.53 to 0.74), 0.89 (95% CI = 0.81 to 0.98), and 0.91 (95% CI = 0.82 to 1.02), respectively. There was little evidence of a difference in total mortality (OR 1.03, 95% CI = 0.90 to 1.18). Higher CVD mortality was observed in the intervention group (OR 1.30, 95% CI = 1.02 to 1.66).
General practice-based health checks are associated with statistically significant, albeit clinically small, improvements in surrogate outcome control, especially among high-risk patients. Most studies were not originally designed to assess mortality.
The coronavirus disease pandemic was declared in March 2020, as the southern hemisphere's winter approached. Australia expected co-circulation of severe acute respiratory syndrome coronavirus 2, ...influenza and other seasonal respiratory viruses. However, influenza notifications were 7,029 (March-September) compared with an average 149,832 for the same period in 2015-2019 corrected, despite substantial testing. Restrictions on movement within and into Australia may have temporarily eliminated influenza. Other respiratory pathogens also showed remarkably changed activity in 2020.
In a trial comparing 100 mg of aspirin with placebo in nearly 20,000 community-dwelling persons 70 years of age or older in Australia and the United States, aspirin use had no effect on the rate of ...survival free from dementia or physical disability.
Effect of cocoa on blood pressure Ried, Karin; Sullivan, Thomas R; Fakler, Peter ...
Cochrane database of systematic reviews,
2012-Aug-15
8
Journal Article
Recenzirano
High blood pressure is an important risk factor for cardiovascular disease attributing to about 50% of cardiovascular events worldwide and 37% of cardiovascular related deaths in Western populations. ...Epidemiological studies suggest that cocoa rich products reduce the risk of cardiovascular disease. Flavanols found in cocoa have been shown to increase the formation of endothelial nitric oxide which promotes vasodilation and therefore blood pressure reduction. Previous meta-analyses have shown that cocoa-rich foods may reduce blood pressure. Recently additional trials had conflicting results.
To determine the effect of flavanol-rich chocolate or cocoa products on blood pressure in people with or without hypertension.
We searched the following electronic databases from inception to November 2011: Cochrane Hypertension Group Specialised Register, CENTRAL, MEDLINE and EMBASE. In addition we searched international trial registries, and the reference lists of review articles and included trials.
Randomised controlled trials (RCT) investigating the effects of chocolate or cocoa products on systolic and diastolic blood pressure in adults for a minimum of two weeks duration.
Two authors independently extracted data and assessed the risk of bias in each trial in consultation with a third author. Random effects meta-analyses on all studies fitting the inclusion criteria were conducted using Review Manager version 5.1 and Stata version 12. Heterogeneity was explored by subgroup analyses and univariate meta-regression analysis of several variables including dosage of flavanol content (total or monomers) in chocolate or cocoa products, blinding, baseline blood pressure, theobromine content, sugar content, body-mass-index (BMI), duration and age.
Twenty studies met the inclusion criteria. Meta-analyses of the 20 studies involving 856 mainly healthy participants revealed a statistically significant blood pressure reducing effect of flavanol-rich cocoa products compared with control in short-term trials of 2-18 weeks duration: Mean difference SBP (95%CI): -2.77 (-4.72, -0.82) mm Hg, p=0.005, n=20; mean difference DBP (95%CI): - 2.20 (-3.46, -0.93) mm Hg, p=0.006, n=19 available for DBP.Trials provided participants with 30-1080 mg of flavanols (mean=545.5 mg) in 3.6-105 g of cocoa products per day in the active intervention group. In half of the trials (n=10) the active group consumed 500-750 mg of flavanols per day. The control group received either a flavanol-free product (n=12) or a low-flavanol containing cocoa powder (6.4 and 41 mg flavanols, n=8). Subgroup meta-analysis of trials with a flavanol-free control group revealed a significant blood pressure reducing effect, in contrast to trials using a low-flavanol product in the control group. This analysis may have been confounded by trial duration and the level of blinding of participants.Trial duration was short (mean 4.4 weeks, range 2-8 weeks, n=19, and one trial of 18 weeks). A significant blood pressure reducing effect was evident in trials of 2 weeks duration (n=9), but not in trials of >2 weeks duration (n=11). It is important to note that seven out of the nine trials (78%) of 2 weeks duration also had a flavanol-free control group. Therefore, subgroup analysis by duration might be confounded by flavanol dosage used in the control groups, and the level of blinding of participants.Adverse effects including gastrointestinal complaints and distaste of the trial product were reported by 5% of patients in the active cocoa intervention group and 1% of patients in the control groups.
Flavanol-rich chocolate and cocoa products may have a small but statistically significant effect in lowering blood pressure by 2-3 mm Hg in the short term.Our findings are limited by the heterogeneity between trials, which was explored by univariate meta-regression and subgroup analyses. Subgroup meta-analysis of trials using a flavanol-free control group revealed a significant blood pressure reducing effect of cocoa, whereas analysis of trials using a low-flavanol control product did not. While it appears that shorter trials of 2 weeks duration were more effective, analysis may be confounded by type of control and unblinding of participants, as the majority of 2-week trials also used a flavanol-free control and unblinding of participants. Results of these and other subgroup analyses based on, for example, age of participants, should be interpreted with caution and need to be confirmed or refuted in trials using direct randomized comparison.Long-term trials investigating the effect of cocoa products are needed to determine whether or not blood pressure is reduced on a chronic basis by daily ingestion of cocoa. Furthermore, long-term trials investigating the effect of cocoa on clinical outcomes are also needed to assess whether cocoa has an effect on cardiovascular events and to assess potential adverse effects associated with chronic ingestion of cocoa products.
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