Chronic coffee consumption has a detrimental effect on aortic stiffness and wave reflections

The role of coffee and potential mediators in subclinical atherosclerosis: insights from Mendelian randomization study

Background and aims

Coffee contains many bioactive compounds, and its inconsistent association with subclinical atherosclerosis has been reported in observational studies. In this Mendelian randomization study, we investigated whether genetically predicted coffee consumption is associated with subclinical atherosclerosis, as well as the role of potential mediators.

Methods

We first conducted a two-sample Mendelian randomization analysis to examine the causal effect of coffee and its subtypes on subclinical atherosclerosis inferred from coronary artery calcification (CAC). Next, the significant results were validated using another independent dataset. Two-step Mendelian randomization analyses were utilized to evaluate the causal pathway from coffee to subclinical atherosclerosis through potential mediators, including blood pressure, blood lipids, body mass index, and glycated hemoglobin. Mendelian randomization analyses were performed using the multiplicative random effects inverse-variance weighted method as the main approach, followed by a series of complementary methods and sensitivity analyses.

Results

Coffee, filtered coffee, and instant coffee were associated with the risk of CAC (β = 0.79, 95% CI: 0.12 to 1.47, p = 0.022; β = 0.66, 95% CI: 0.17 to 1.15, p = 0.008; β = 0.66, 95% CI: 0.20 to 1.13, p = 0.005; respectively). While no significant causal relationship was found between decaffeinated coffee and CAC (β = -1.32, 95% CI: -2.67 to 0.04, p = 0.056). The association between coffee and CAC was validated in the replication analysis (β = 0.27, 95% CI: 0.07 to 0.48, p = 0.009). Body mass index mediated 39.98% of the effect of coffee on CAC (95% CI: 9.78 to 70.19%, p = 0.009), and 5.79% of the effect of instant coffee on CAC (95% CI: 0.54 to 11.04%, p = 0.030).

Conclusion

Our study suggests that coffee other than decaffeinated coffee increases the risk of subclinical atherosclerosis inferred from CAC. Body mass index mediated 39.98 and 5.79% of the causal effects of coffee and instant coffee on CAC, respectively. Coffee should be consumed with caution, especially in individuals with established cardiovascular risk factors, and decaffeinated coffee appears to be a safer choice.

Habitual coffee and caffeinated beverages consumption is inversely associated with arterial stiffness and central and peripheral blood pressure

The effects of chronic coffee consumption on the cardiovascular system are still under debate. Aortic stiffness, wave reflections, and central and peripheral blood pressure (BP) are milestone indicators of cardiovascular-risk. We sought to investigate the association between coffee and caffeine consumption, arterial stiffness, and central/peripheral BP. Aortic stiffness was evaluated via pulse wave velocity (PWV); wave reflections with the augmentation index (AIx);peripheral systolic BP (SBP), diastolic BP (DBP), and central BP (cSBP/cDBP) were non-invasively assessed. Coffee and caffeine consumption was ascertained using a questionnaire. A linear inverse relationship between coffee and caffeine consumption and arterial stiffness and central and peripheral BP was found.Light coffee and caffeine consumers showed β-coefficients for PWV-0.15, SBP-3.61, DBP-2.48, cSBP-3.21, and cDBP-2.18 (all p values < 0.05).Present findings suggest that coffee and caffeine consumption is inversely associated with arterial stiffness and central and peripheral BP in a large population sample. Interventional prospective studies are needed to demonstrate the causal association.

Effects of coffee consumption on arterial stiffness and endothelial function: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Endothelial function (EF) and arterial stiffness (AS) are predictors of cardiovascular disease. As previous research concerning the effect of coffee intake on EF and AS was controversial, we conducted a systematic review and meta-analysis to synthesize research.

METHODS

We performed a systematic search in PubMed, Scopus and Web of Science to find clinical trials investigating the effect of coffee intake on EF or AS up to March 2020.Random-effects models were used to estimate the pooled weighted mean difference (WMD) between intervention and control groups for randomized controlled trials (RCTs). Between study heterogeneity was estimated using Cochran's Q and the I ²-inconsistency index. Internal validity of included randomized trials was determined with the Cochrane Collaboration's tool for assessing the risk of bias.

RESULTS

Twenty-three articles were included for qualitative and 11 articles for quantitative synthesis. Meta-analysis of 14 RCTs (nine articles) indicated a positive short-term (postprandial) effect of coffee intake on flow-mediated dilation (FMD) as a measure of EF (WMD: 1.93%[95% CI: 1.10-2.75]; I ²= 97.9%). Meta-analysis of three long-term RCTs(two articles) found no such effect on FMD (WMD: -0.08% [-3.82 to 3.66]; I ²= 61.4%).Most short-term information was from studies at low or unclear risk of bias, while the proportion of long-term information from studies at high risk of bias was considerable.

CONCLUSION

The results from this meta-analysis suggest a beneficial short-term effect of coffee intake on EF as measured by FMD. However, there might be unfavorable effects on AS. Our findings must be interpreted cautiously as the number of studies were low and included studies had a considerable risk of bias.

Effect of tea and coffee consumption on the blood pressure, pulse wave velocity and aortic pressures in young healthy individuals

Caffeine present in tea and coffee, the most commonly used beverages, has been implicated to have long term effects on cardiovascular system. The aim of this study was to document the acute and chronic effects of tea and coffee consumption on blood pressure, pulse wave velocity and aortic pressures in young, healthy individuals. This observational study was conducted on 86 healthy MBBS student volunteers of both genders between the age group of 18-27 years. Cardiovascular parameters (heart rate, peripheral blood pressure, central blood pressure, pulse wave velocity, augmentation pressure) were measured using PeriScope. Participants were divided into 3 groups based on their history of consuming tea/coffee/both/none. Data collected was analyzed using SPSS 17.0. ANOVA or Welsh test of equality of means was used for knowing the differences for scale variables. Paired sample t test was used to know the acute effect of coffee consumption among group 1 participants in a before-after design. In regular tea consumers, the bilateral brachial SBP, DBP and MAP were significantly higher than individuals who did not consume tea regularly; similar results in these parameters were also observed in regular coffee drinkers. However the lower limb arterial parameters were not markedly differently in tea/coffee group compared to non-drinkers. In both tea and coffee group, AoSP and AoDP were significantly higher than non-drinkers. Additionally, coffee drinking has acute stimulatory effects on CVS as evident by increase in peripheral and central vascular parameters.

Conflicting Effects of Coffee Consumption on Cardiovascular Diseases: Does Coffee Consumption Aggravate Pre-existing Risk Factors?

Coffee is one of the most popular beverages worldwide. Its effect on health is generally regarded as beneficial in many studies. However, there are growing concerns about the adverse effect of coffee consumption on cardiovascular disease (CVD) due to the potential aggravating impact on the cardiovascular system attributed to various compounds within coffee. This review is focused on deteriorative effects of coffee consumption on CVDs with possible mechanisms. Patients with risk factors of CVDs should prudently consider heavy consumption of coffee as it may exacerbate hypertension, dyslipidemia, and atherosclerosis, and increase the odds of cardiovascular events. J-shaped or U-shaped dose-response graphs of coffee consumption and CVD parameters partially explain the inconsistency of conclusions between coffee studies on CVD, highlighting a moderate intake of coffee. Moreover, there are discrepancies in results from clinical studies elucidating considerable influences of confounding factors including gender and smoking status on outcomes of those conducted to reveal the actual impact of coffee consumption on CVDs. Physical features of subjects including genetic variations and body mass index (BMI) make it difficult to determine moderate intake of coffee for individuals in terms of caffeine metabolism. Further epidemiological studies with consideration about characteristics of the study population are needed to determine the exact effect of coffee consumption on CVD.

Association between lifetime coffee consumption and late life cerebral white matter hyperintensities in cognitively normal elderly individuals

Coffee consumption is associated with cerebral hypoperfusion that may contribute to the development of cerebral white matter hyperintensities (WMH). We investigated the effect of lifetime coffee consumption on the volume of WMH (V_WMH) in late life, and compared the effect between men and women since caffeine clearance may be different between sexes. We enrolled 492 community-dwelling cognitively normal elderly individuals (73.4 ± 6.7 years old on average) from the Korean Longitudinal Study on Cognitive Aging and Dementia. We evaluated their patterns and amounts of coffee consumption using a study-specific standardized interview and estimated cerebral V_WMH by automatic segmentation of brain fluid-attenuated inversion recovery sequence magnetic resonance images. Higher cumulative lifetime coffee consumption was associated with higher logV_WMH in both sexes (p = 0.030). The participants who consumed more than 2 cups of coffee per day on average in their lifetime showed higher logV_WMH in late life than those who consumed less. When both sexes were analyzed separately, these coffee-logV_WMH associations were found only in women, although the volumes of brain and white matter of women were smaller than those of men. Our findings suggest that prolonged high coffee consumption may be associated with the risk of WMH in late life.

Is e-cigarette use associated with coronary heart disease and myocardial infarction? Insights from the 2016 and 2017 National Health Interview Surveys

BACKGROUND

This study analyzed the National Health Interview Surveys (NHIS) of 2016 (n = 33,028) and 2017 (n = 26,742) to examine whether e-cigarette use is consistently associated with myocardial infarction (MI) and coronary heart disease (CHD).

METHODS

Surveys were examined separately and pooled. Logistic regression analysis was used, with demographics, e-cigarette use, smoking and risk factors for CHD (hypertension, hypercholesterolemia, and diabetes) being independent variables. Former smokers were subclassified according to quit duration (⩽ 6 and > 6 years).

RESULTS

For MI, an association was observed with some days e-cigarette (but not daily) use in the 2017 survey (OR: 2.11, 95% CI: 1.14-3.88, p = 0.017). No statistically significant association was observed in the pooled analysis (daily e-cigarette use: OR: 1.35, 95% CI: 0.80-2.27, p = 0.267). For CHD, an association was observed with daily e-cigarette use in the 2016 survey (OR: 1.89, 95% CI: 1.01-3.53, p = 0.047). From the pooled analysis, no association was found between any pattern of e-cigarette use and CHD. In single-year and pooled analysis, both MI and CHD were strongly associated with all patterns of smoking, hypertension, hypercholesterolemia, diabetes, and age.

CONCLUSIONS

The pooled analysis of the 2016 and 2017 NHIS showed no association between e-cigarette use and MI or CHD. The associations between established risk factors, including smoking, and both conditions were remarkably consistent. The inconsistent associations observed in single-year surveys and the cross-sectional design of the NHIS cannot substantiate any link between e-cigarette use and an elevated risk for MI or CHD. Longitudinal studies are needed to explore the effects of e-cigarette use on cardiovascular disease.

Associations of Urinary Caffeine and Caffeine Metabolites With Arterial Stiffness in a Large Population-Based Study

OBJECTIVE

To assess the influence of caffeine on arterial stiffness by exploring the association of urinary excretion of caffeine and its related metabolites with pulse pressure (PP) and pulse wave velocity (PWV).

PARTICIPANTS AND METHODS

Families were randomly selected from the general population of 3 Swiss cities from November 25, 2009, through April 4, 2013. Pulse pressure was defined as the difference between the systolic and diastolic blood pressures obtained by 24-hour ambulatory monitoring. Carotid-femoral PWV was determined by applanation tonometry. Urinary caffeine, paraxanthine, theophylline, and theobromine excretions were measured in 24-hour urine collections. Multivariate linear and logistic mixed models were used to explore the associations of quartiles of urinary caffeine and metabolite excretions with PP, high PP, and PWV.

RESULTS

We included 863 participants with a mean ± SD age of 47.1±17.6 years, 24-hour PP of 41.9±9.2 mm Hg, and PWV of 8.0±2.3 m/s. Mean (SE) brachial PP decreased from 43.5 (0.5) to 40.5 (0.6) mm Hg from the lowest to the highest quartiles of 24-hour urinary caffeine excretion (P<.001). The odds ratio (95% CI) of high PP decreased linearly from 1.0 to 0.52 (0.31-0.89), 0.38 (0.22-0.65), and 0.31 (0.18-0.55) from the lowest to the highest quartile of 24-hour urinary caffeine excretion (P<.001). Mean (SE) PWV in the highest caffeine excretion quartile was significantly lower than in the lowest quartile (7.8 [0.1] vs 8.1 [0.1] m/s; P=.03). Similar associations were found for paraxanthine and theophylline, whereas no associations were found with theobromine.

CONCLUSION

Urinary caffeine, paraxanthine, and theophylline excretions were associated with decreased parameters of arterial stiffness, suggesting a protective effect of caffeine intake beyond its blood pressure-lowering effect.

Serum brain-derived neurotrophic factor predicting reduction in pulse pressure after a one-hour rest in nurses working night shifts

Night shift work is associated with cardiovascular disease and central nervous system disorders in female nurses. Brain-derived neurotrophic factor (BDNF) exerts protective effects on neural and endothelial functions. This study examined the association between serum BDNF levels and pulse pressure after rest in female nurses working night shifts. In this study, blood samples were collected for BDNF measurement after a night shift when nurses had been working night shifts for three continuous weeks. Blood pressure was assessed before and after a one-hour morning rest within a week of resuming the night shift after one month without any night shift work. The pulse pressure of nurses (n = 48, age 29 ± 5 years) was significantly reduced (from 43 ± 7 to 41 ± 6 mmHg, P = 0.003) after rest, and serum BDNF were significantly and inversely correlated with pulse pressure changes (r = −0.435, P = 0.002). Higher serum BDNF was an independent factor for greater reduction in pulse pressure (95%CI = −0.609 ‒ −0.174, P = 0.001). Using a receiver operating characteristic curve analysis, serum BDNF >20.6 ng/mL predicted a pulse pressure reduction after a one-hour rest (sensitivity 66.7%, specificity 77.8%). In conclusion, higher serum BDNF predicted greater recovery of pulse pressure after a one-hour rest in female nurses after night shift work.

Electronic cigarettes: an aid in smoking cessation, or a new health hazard?

The issue of electronic cigarettes is one of the most controversial topics in public health. There is intense debate and dividing opinions about their use patterns, health effects and association with smoking. This is expected since they were only recently introduced to the market and they refer to a harm-reduction approach and strategy that is not universally accepted for smoking and tobacco use in the public health community. Three main factors determine the public health impact of electronic cigarettes: (1) their safety/risk profile, both relative to smoking and in absolute terms; (2) their effectiveness for smoking reduction and cessation; (3) the patterns of use by different population subgroups, especially never-smokers, and adoption of use by youth. This analysis presents a brief overview of currently available evidence and gaps in research covering these three factors.

Whole grain consumption is negatively correlated with obesity-associated aortic stiffness: A hypothesis

OBJECTIVE

Obesity is a risk factor for cardiovascular disease that increases aortic stiffness, which predicts future cardiovascular events. Additionally, obesity is associated with overconsumption, which contributes to aortic stiffening. Recent work has highlighted the role of various foods and nutrients on aortic stiffness among the general population. The objective of the present study was to explore the influence of dietary factors on obesity-associated aortic stiffness, as food choices might be a potential explanation for accelerated aortic stiffening in obesity rather than overconsumption alone.

METHODS

Data collected in our laboratory were evaluated in aggregate considering obese men with available measures of aortic stiffness and habitual dietary intake (n = 22). Aortic stiffness was assessed with the gold standard carotid-femoral pulse wave velocity, and habitual dietary intake was determined with the National Institutes of Health's Dietary History Questionnaire-II.

RESULTS

Whole grain consumption predicted obesity-associated aortic stiffness in regression analyses (R² = 0.29, P = 0.010). This correlation remained significant after adjusting for traditional risk factors (age, body mass index, blood pressure) (R² = 0.27, P = 0.027). Overconsumption determined by daily caloric intake was not predictive of aortic stiffness (R² = 0.09, P = 0.17) nor was total fiber content (R² = 0.06, P = 0.29).

CONCLUSIONS

These findings suggest a potential role of whole grains to protect against aortic stiffness even when dietary overconsumption is present. Fiber content has been proposed as a major beneficial component in whole grains, but it did not correlate with obesity-related aortic stiffness, suggesting whole grains may have a unique and potentially synergistic role in the protection of obesity-associated aortic health.

Arterial stiffness and cognitive impairment

BACKGROUND

Arterial stiffness is one of the earliest indicators of changes in vascular wall structure and function and may be assessed using various indicators, such as pulse-wave velocity (PWV), the cardio-ankle vascular index (CAVI), the ankle-brachial index (ABI), pulse pressure (PP), the augmentation index (AI), flow-mediated dilation (FMD), carotid intima media thickness (IMT) and arterial stiffness index-β. Arterial stiffness is generally considered an independent predictor of cardiovascular and cerebrovascular diseases. To date, a significant number of studies have focused on the relationship between arterial stiffness and cognitive impairment.

OBJECTIVES AND METHODS

To investigate the relationships between specific arterial stiffness parameters and cognitive impairment, elucidate the pathophysiological mechanisms underlying the relationship between arterial stiffness and cognitive impairment and determine how to interfere with arterial stiffness to prevent cognitive impairment, we searched PUBMED for studies regarding the relationship between arterial stiffness and cognitive impairment that were published from 2000 to 2017. We used the following key words in our search: "arterial stiffness and cognitive impairment" and "arterial stiffness and cognitive impairment mechanism". Studies involving human subjects older than 30years were included in the review, while irrelevant studies (i.e., studies involving subjects with comorbid kidney disease, diabetes and cardiac disease) were excluded from the review.

RESULTS

We determined that arterial stiffness severity was positively correlated with cognitive impairment. Of the markers used to assess arterial stiffness, a higher PWV, CAVI, AI, IMT and index-β and a lower ABI and FMD were related to cognitive impairment. However, the relationship between PP and cognitive impairment remained controversial. The potential mechanisms linking arterial stiffness and cognitive impairment may be associated with arterial pulsatility, as greater arterial pulsatility damages the cerebral microcirculation, which causes various phenomena associated with cerebral small vessel diseases (CSVDs), such as white matter hyperintensities (WMHs), cerebral microbleeds (CMBs), and lacunar infarctions (LIs). The mechanisms underlying the relationship between arterial stiffness and cognitive impairment may also be associated with reductions in white matter and gray matter integrity, medial temporal lobe atrophy and Aβ protein deposition. Engaging in more frequent physical exercise; increasing flavonoid and long-chain n-3 polyunsaturated fatty acid consumption; increasing tea, nitrite, dietary calcium and vitamin D intake; losing weight and taking medications intended to improve insulin sensitivity; quitting smoking; and using antihypertensive drugs and statins are early interventions and lifestyle changes that may be effective in preventing arterial stiffness and thus preventing cognitive impairment.

CONCLUSION

Arterial stiffness is a sensitive predictor of cognitive impairment, and arterial stiffness severity has the potential to serve as an indicator used to facilitate treatments designed to prevent or delay the onset and progression of dementia in elderly individuals. Early treatment of arterial stiffness is beneficial and recommended.

J-shaped relationship between habitual coffee consumption and 10-year (2002-2012) cardiovascular disease incidence: the ATTICA study

PURPOSE

The purpose of this work was to evaluate the association between coffee consumption and 10-year cardiovascular disease (CVD) incidence in the ATTICA study, and whether this is modified by the presence or absence of metabolic syndrome (MetS) at baseline.

METHODS

During 2001-2002, 3042 healthy adults (1514 men and 1528 women) living in the greater area of Athens were voluntarily recruited to the ATTICA study. In 2011-2012, the 10-year follow-up was performed in 2583 participants (15% of the participants were lost to follow-up). Coffee consumption was assessed by a validated food-frequency questionnaire at baseline (abstention, low, moderate, heavy). Incidence of fatal or non-fatal CVD event was recorded using WHO-ICD-10 criteria and MetS was defined by the National Cholesterol Education Program Adult Treatment panel III (revised) criteria.

RESULTS

Overall, after controlling for potential CVD risk factors, the multivariate analysis revealed a J-shaped association between daily coffee drinking and the risk for a first CVD event in a 10-year period. Particularly, the odds ratio for low (<150 ml/day), moderate (150-250 ml/day) and heavy coffee consumption (>250 ml/day), compared to abstention, were 0.44 (95% CI 0.29-0.68), 0.49 (95% CI 0.27-0.92) and 2.48 (95% CI 1.56-1.93), respectively. This inverse association was also verified among participants without MetS at baseline, but not among participants with the MetS.

CONCLUSIONS

These data support the protective effect of drinking moderate quantities of coffee (equivalent to approximately 1-2 cups daily) against CVD incidents. This protective effect was only significant for participants without MetS at baseline.

The role of coffee consumption on the 10-year (2004-2014) Acute Coronary Syndrome (ACS) incidence among cardiac patients: the GREECS observational study

The association between long-term coffee consumption and 10-year cardiovascular disease incidence among Acute Coronary Syndrome (ACS) patients was evaluated. From 2003 to 2004, 2172 ACS consecutive patients from six major Greek hospitals were enrolled. During 2013-2014, the 10-year follow-up was performed (88% participation rate) and recurrent fatal or non-fatal ACS was recorded. Baseline coffee consumption (cups/day) was assessed using a semi-quantitative Food Frequency Questionnaire. Multi adjusted analysis revealed that 1-2 cups of coffee/day versus no consumption had an adverse effect on the ACS incidence [odds ratio (OR) = 1.35, 95% confidence interval (CI) 1.01, 1.79]. In subgroup analysis, with hypertension as strata, only the normotensive reached significance. Odds ratios for 1-2 and ≥3 cups relative to no consumption were [OR = 1.66, 95% CI 1.07, 2.60] and [OR = 1.86, 95% CI 1.06, 3.27], respectively, after controlling for potential confounders. Thus, avoidance of coffee may be of high importance to ameliorate disease prognosis among cardiac patients.

Tea, but not coffee consumption, is associated with components of arterial pressure. The Observation of Cardiovascular Risk Factors study in Luxembourg

There is uncertainty regarding the impact of tea and coffee consumption on arterial blood pressure. The present study aimed to examine the association between blood pressure (BP) components, namely, systolic BP (SBP), diastolic BP, mean arterial pressure, and pulse pressure (PP), and tea or coffee consumption, taking into account simultaneous consumption. The study population was derived from a national cross-sectional stratified sample of 1352 individuals aged 18 to 69 years, recruited between November 2007 and January 2009 to participate in the Observation of Cardiovascular Risk Factors in Luxembourg study. We hypothesized that greater tea consumption would be independently associated with lower BP. Tea and coffee consumptions in deciliters per day were obtained from a semiquantitative food frequency questionnaire. Participants were classified into 3 groups: nonconsumers, ≤3-dL/d consumers, and >3-dL/d consumers of each beverage separately. After exclusion of subjects taking antihypertensive medications, several general linear models were performed to investigate the independent relationship between tea/coffee consumption and BP components. Tea consumers (36.3%) were more likely to be younger women, nonsmokers, with better cardiometabolic profiles, and less frequent chronic pathologies, whereas the reverse was true for coffee consumers (88%). Greater tea consumption was associated with lower SBP and PP values, after adjustment for age, sex, education, lifestyle, and dietary confounding factors, including coffee drinking. No association between BP components and coffee consumption was observed. Daily consumption of 1 dL of tea was associated with a significant reduction of SBP by 0.6 mm Hg and PP by 0.5 mm Hg. Given the widespread consumption of tea and coffee throughout the world, together with the major cardiovascular disease risk, our findings have important implications for human health.

Effect of Caffeine Chronically Consumed During Pregnancy on Adenosine A1 and A2A Receptors Signaling in Both Maternal and Fetal Heart from Wistar Rats

Background: Caffeine is the most widely consumed psychoactive substance in the world, even during pregnancy. Its stimulatory effects are mainly due to antagonism of adenosine actions by blocking adenosine A₁ and A_2A receptors. Previous studies have shown that caffeine can cross the placenta and therefore modulate these receptors not only in the fetal brain but also in the heart. Methods: In the present work, the effect of caffeine chronically consumed during pregnancy on A₁ and A_2A receptors in Wistar rat heart, from both mothers and their fetuses, were studied using radioligand binding, Western-blotting, and adenylyl cyclase activity assays, as well as reverse transcription polymerase chain reaction. Results: Caffeine did not significantly alter A₁R neither at protein nor at gene expression level in both the maternal and fetal heart. On the contrary, A_2AR significantly decreased in the maternal heart, although mRNA was not affected. Gi and Gs proteins were also preserved. Finally, A₁R-mediated inhibition of adenylyl cyclase activity did not change in the maternal heart, but A_2AR mediated stimulation of this enzymatic activity significantly decreased according to the detected loss of this receptor. Conclusions: Opposite to the downregulation and desensitization of the A₁R/AC pathway previously reported in the brain, these results show that this pathway is not affected in rat heart after caffeine exposure during pregnancy. In addition, A_2AR is downregulated and desensitized in the maternal heart, suggesting a differential modulation of these receptor-mediated pathways by caffeine.

Postprandial effect of dietary fat quantity and quality on arterial stiffness and wave reflection: a randomised controlled trial

Background

Arterial stiffness is a component of vascular function and an established risk factor for cardiovascular disease. There is a lack of conclusive evidence on the effect of a meal rich in monounsaturated fat (MUFA) compared with an isoenergetic meal rich in saturated fat (SFA) on postprandial vascular function and specifically on arterial stiffness.

Methods

Twenty healthy, non-smoking males (BMI 24 ± 2 kg/m²; age 37.7 ± 14.4 y) participated in this single-blind, randomised, cross-over dietary intervention study. Each subject was randomised to receive a high-fat test-meal (3 MJ; 56 ± 2 g fat) at breakfast on 2 separate occasions, one rich in oleic acid (MUFA-meal) and one rich in palmitic acid (SFA-meal), and the meals were isoenergetic. Blood pressure (BP), arterial stiffness (PWV) and arterial wave reflection (augmentation index, AIx) were measured using applanation tonometry at baseline and every 30 minutes up to 4 hours after the ingestion of the test-meals.

Results

All subjects completed both arms of the dietary intervention. There was no significant difference in BP parameters, PWV or AIx at baseline between the two treatments (P > 0.05). There was a significant increase in brachial and aortic BP, mean arterial pressure (MAP), heart rate and PVW (time, P < 0.05) over the four hours after consumption of the fat-rich test-meal although the increase in PWV was no longer significant when adjusted for the increase in MAP. There was no difference in PWV between the two treatments (treatment*time, P > 0.05). There was a significant reduction in AIx (time, P < 0.05) over the four hour postprandial period although this was no longer significant when adjusted for the increase in heart rate and MAP (time, P > 0.05). There was no difference in AIx between the two treatments (treatment*time, P > 0.05). However, the reduction in heart rate corrected augmentation index (AIx₇₅) was significant when corrected for the increase in MAP (time, P < 0.01) with no differential effect of the treatments (treatment*time, P > 0.05).

Conclusions

This study has demonstrated a BP dependent increase in PWV and a decrease in arterial wave reflection in the four hour period in response to a high-fat meal. There was no evidence however that replacement of some of the SFA with MUFA had a differential effect on these parameters. The study highlights the need for further research to understand the effects of the substitution of SFA with MUFA on non-serum, new and emerging risk factors for CVD such as arterial stiffness.

The effects of pre- and post-exercise consumption of multi-ingredient performance supplements on cardiovascular health and body fat in trained men after six weeks of resistance training: a stratified, randomized, double-blind study

Background

The cardiovascular (CV) and metabolic health benefits or risks associated with consumption of multi-ingredient performance supplements (MIPS) in conjunction with periodized resistance training (RT) in resistance-trained men are unknown. This population is a major target audience for performance supplements, and therefore, the purpose of this study was to investigate the combined effect of RT and commercially available pre- and post-exercise performance supplements on CV health and body fat in resistance-trained men.

Methods

Twenty-four resistance-trained men completed six weeks (three times/week) of periodized RT while either ingesting SHOT 15-min pre-exercise and SYN immediately post-exercise (multi-ingredient performance supplement group: MIPS) or an isocaloric maltodextrin placebo 15-min pre-exercise and immediately post-exercise (Placebo group). Before and after six weeks of RT and supplementation, resting heart rate (HR), blood pressure (BP), total body fat, android fat, gynoid fat, fat-free mass (FFM) and fasting blood measures of glucose, lipids, nitrate/nitrite (NOx), cortisol and high sensitivity C-reactive protein (hs-CRP) were measured. Statistical analysis was conducted using a one-way ANOVA for baseline differences and a 2 × 2 (group × time) repeated measures ANOVA and Tukey post-hoc tests where appropriate. Significance was set at p < 0.05.

Results

There was no group × time interaction for HR, BP, blood glucose, lipids, NOx, hs-CRP, cortisol concentrations or body fat. However, there was a time effect where significant decreases in body fat (mean ± SD; MIPS: -1.2 ± 1.2%; Placebo: -0.9 ± 1.1%), android fat (MIPS: -1.8 ± 2.1%; Placebo: -1.6 ± 2.0%), and gynoid fat (MIPS: -1.3 ± 1.6%; Placebo: -1.0 ± 1.4%) for both groups were observed. FFM increased in both groups, and a group × time interaction was observed with MIPS increasing significantly more than the Placebo group (4.2% vs. 1.9%).

Conclusions

Six weeks of MIPS ingestion and periodized RT does not alter CV health parameters or blood indices of health or body fat more than a Placebo treatment in healthy, resistance-trained men. However, MIPS significantly increased FFM more than Placebo.

Consumption of a boiled Greek type of coffee is associated with improved endothelial function: The Ikaria Study

Objective:

The association of coffee consumption with cardiovascular disease remains controversial. Endothelial function is associated with cardiovascular risk. We examined the association between chronic coffee consumption and endothelium function in elderly inhabitants of the island of Ikaria.

Methods:

The analysis was conducted on 142 elderly subjects (aged 66–91 years) of the Ikaria Study. Endothelial function was evaluated by ultrasound measurement of flow-mediated dilation (FMD). Coffee consumption was evaluated based on a food frequency questionnaire and was categorized as ‘low’ (< 200 ml/day), ‘moderate’ (200–450 ml/day), or ‘high’ (> 450 ml/day).

Results:

From the subjects included in the study, 87% consumed a boiled Greek type of coffee. Moreover, 40% had a ‘low’, 48% a ‘moderate’ and 13% a ‘high’ daily coffee consumption. There was a linear increase in FMD according to coffee consumption (‘low’: 4.33 ± 2.51% vs ‘moderate’: 5.39 ± 3.09% vs ‘high’: 6.47 ± 2.72%; p = 0.032). Moreover, subjects consuming mainly a boiled Greek type of coffee had a significantly higher FMD compared with those consuming other types of coffee beverages ( p = 0.035).

Conclusions:

Chronic coffee consumption is associated with improved endothelial function in elderly subjects, providing a new connection between nutrition and vascular health.

How can diet influence the risk of stroke?

Cerebrovascular diseases are the second cause of mortality in the world, and hypertension is considered a main risk factor for occurrence of stroke. The mechanisms responsible for the increased stroke risk remain unclear. However, dietary interventions have been applied in the management and treatment of their risk factors, which include increased blood pressure levels, obesity, diabetes, and dyslipidemia. Further studies should be conducted to assess the effects of carotenoids, flavonoids, n-3 polyunsaturated fats, and lower salt and high glycemic index intake in risk of stroke.

Caffeine in hot drinks elicits cephalic phase responses involving cardiac activity

Caffeine stimulates both oropharyngeal and gut bitter taste receptors (hTAS2Rs) and so has the potential to elicit reflex autonomic responses. Coffee containing 130 mg caffeine has been reported to increase heart rate for 30 min post-ingestion. Whereas added-caffeine, in doses of 25 to 200 mg, ingested with decaffeinated coffee/tea decreases heart rate 10 to 30 min post-ingestion. This study aimed to clarify caffeine's chemosensory impact. Double-espresso coffees were compared to a placebo-control capsule in a double-blind between-measures design. Coffees tested were regular coffee (130 mg caffeine) and decaffeinated coffee with added-caffeine (0, 67 and 134 mg). Cardiovascular measures from three post-ingestion phases: 1) 0 to 5; 2) 10 to 15; and 3) 25 to 30 min; were compared to pre-ingestion measures. Participants comprised 11 women in the control group and 10 women in the test group. Decaffeinated coffee elicited no changes. Decaffeinated coffee with 67 mg caffeine: decreased dp/dt in Phase 1. Decaffeinated coffee with 134 mg caffeine: increased heart rate in Phases 1 and 2; decreased spontaneous baroreflex sensitivity in Phase 1; and increased diastolic pressure in Phases 2 and 3. Regular coffee: increased heart rate in Phases 1 and 2; decreased dp/dt in all phases; and decreased systolic pressure in Phase 1. Caffeine is the substance in regular coffee which elicits chemosensory autonomic reflex responses, which involves heart activity and the baroreflex. Compared to the caffeine in regular coffee, added-caffeine elicits somewhat different chemosensory responses including a more pronounced pressor effect and resetting of the baroreflex. Caffeine in commonly consumed amounts, as well as modulating body processes by blocking adenosine receptors, can elicit reflex autonomic responses during the ingestion of caffeinated drinks. It is plausible that caffeine stimulates hTAS2Rs, during the ingestion of coffee, eliciting cephalic phase responses. These cephalic phase responses likely result from vagal withdrawal and it is uncertain whether they enhance digestion or not.

Impact of acute caffeine ingestion on endothelial function in subjects with and without coronary artery disease

Although coffee is a widely used, pharmacologically active beverage, its impact on the cardiovascular system is controversial. To explore the effect of acute caffeine ingestion on brachial artery flow-mediated dilation (FMD) in subjects without coronary artery disease (CAD; controls) and patients with CAD, we prospectively assessed brachial artery FMD in 40 controls and 40 age- and gender-matched patients with documented stable CAD on 2 separate mornings 1 week to 2 weeks apart. After overnight fasting, discontinuation of all medications for ≥12 hours, and absence of caffeine for >48 hours, participants received capsules with caffeine 200 mg or placebo. One hour after drug ingestion, participants underwent brachial artery FMD and nitroglycerin-mediated dilation (NTG) using high-resolution ultrasound. As expected, patients with CAD were more often diabetic, hypertensive, obese, dyslipidemic, and smoked more than controls (p <0.01 for all comparisons). Aspirin, Clopidogrel, angiotensin-converting enzyme inhibitors, β blockers, and statins were significantly more common in patients with CAD than in controls (p <0.01 for all comparisons). At baseline, FMD, but not NTG, was significantly lower in patients with CAD compared to controls. Acute caffeine ingestion significantly increased FMD (patients with CAD 5.6 ± 5.0% vs 14.6 ± 5.0%, controls 8.4 ± 2.9% vs 18.6 ± 6.8%, p <0.001 for all comparisons) but not NTG (patients with CAD 13.0 ± 5.2% vs 13.8 ± 6.1%, controls 12.9 ± 3.9% vs 13.9 ± 5.8%, p = NS for all comparisons) and significantly decreased high-sensitivity C-reactive protein (patients with CAD 2.6 ± 1.4 vs 1.4 ± 1.2 mg/L, controls 3.4 ± 3.0 vs 1.2 ± 1.0 mg/L, p <0.001 for all comparisons) in the 2 groups compared to placebo. In conclusion, acute caffeine ingestion significantly improved endothelial function assessed by brachial artery FMD in subjects with and without CAD and was associated with lower plasma markers of inflammation.

Consumption of filtered and boiled coffee and the risk of first acute myocardial infarction; a nested case/referent study

BACKGROUND AND AIM

In northern Sweden, consumption of both filtered and boiled coffee is common. Boiled coffee, especially popular in rural areas, is known to raise blood lipids, a risk factor for acute myocardial infarction (MI). To our knowledge, only one epidemiological study, a case-control study from Sweden, has investigated boiled coffee in MI, noting an increased risk at high consumption levels in men, and no association in women. The aim of the present nested case-referent study was to relate consumption of filtered and boiled coffee to the risk of first MI.

METHODS AND RESULTS

The study subjects were 375 cases (303 men, 72 women) and 1293 matched referents from the population-based Northern Sweden Health and Disease Study. Coffee consumption was assessed by food frequency questionnaire. Risk estimates were calculated by conditional logistic regression. A statistically significant positive association was found between consumption of filtered coffee and MI risk in men [odds ratio for consumption > or = 4 times/day versus < or = 1 time/day 1.73 (95% CI 1.05-2.84)]. In women, a similar association was observed, but for boiled coffee [odds ratio 2.51 (95% CI 1.08-5.86)]. After adjustment for current smoking, postsecondary education, hypertension, and sedentary lifestyle, the results for women were no longer statistically significant.

CONCLUSION

Consumption of filtered coffee was positively associated with the risk of a first MI in men. A similar tendency was observed for boiled coffee in women, but the result was not statistically significant in multivariate analysis. Further investigation in a larger study is warranted.

Arterial stiffness: clinical relevance, measurement and treatment

Most traditional cardiovascular risk factors alter the structure and/or function of arteries. An assessment of arterial wall integrity could therefore allow accurate prediction of cardiovascular risk in individuals. The term 'arterial stiffness' denotes alterations in the mechanical properties of arteries, and much effort has focused on how best to measure this. Pulse pressure, pulse wave velocity, pulse waveform analysis, localized assessment of blood vessel mechanics and other methods have all been used. We review the methodology underlying each of these measures, and present an evidence-based critique of their relative merits and limitations. An overview is also given of the drug therapies that may prove useful in the treatment of patients with altered arterial mechanics.

Long-term, moderate coffee consumption is associated with lower prevalence of diabetes mellitus among elderly non-tea drinkers from the Mediterranean Islands (MEDIS Study)

BACKGROUND

We evaluated the association between coffee drinking and the prevalence of type 2 diabetes mellitus in elderly people from the Mediterranean islands.

METHODS

During 2005-2007, 500 men and 437 women (aged 65 to 100 years) from the islands of Cyprus (n = 300), Mitilini (n = 142), Samothraki (n = 100), Cephalonia (n = 104), Corfu (n = 160) and Crete (n = 131) participated in the survey. Cardiovascular disease (CVD) risk factors (i.e. hypertension, diabetes, hypercholesterolemia and obesity), as well as behavioral, lifestyle and dietary characteristics were assessed using face-to-face interviews and standard procedures. Among various factors, fasting blood glucose was measured and prevalence of type 2 diabetes mellitus was estimated, according to the established American Diabetes Association (ADA) criteria, while all participants were asked about the frequency of any type of coffee consumption over the last year.

RESULTS

Coffee drinking was reported by 84% of the participants, the majority of whom drank boiled coffee. The participants reported that they had consumed coffee for at least 30 years of their life. Data analysis adjusted for various potential confounders, revealed that, compared to non-consumption, the multi-adjusted odds ratio for having diabetes was 0.47 (95%, CI 0.32 to 0.69) for 1-2 cups/day, while it was 1.05 (95%, CI 0.70 to 1.55) for >3 cups/day, after adjusting for various potential confounders. The association of coffee drinking with diabetes was significant only among non-tea drinkers. Increased coffee intake was not associated with diabetes prevalence.

CONCLUSION

The data presented suggest that moderate coffee drinking is associated with a lower likelihood of having diabetes, after adjusting for various potential confounders.

Coffee consumption and risk of type 2 diabetes and heart disease

Coffee seems to have distinct acute and long-term effects on health, which can be modified by genetic background. Coffee consumption is potentially protective against the development of type 2 diabetes, but given the lack of a solid biological basis for this association, and the possible adverse cardiovascular effects of coffee, recommendations for optimal coffee intake are difficult to establish.

Tea consumption and infarct-related ventricular arrhythmias: the determinants of myocardial infarction onset study

BACKGROUND

Tea consumption is associated with lower post-infarct mortality among patients with acute myocardial infarction. We previously found preliminary evidence that tea consumption may also be associated with lower risk of infarct-related ventricular arrhythmias.

METHODS

Between 1989 and 1996, 3882 subjects with AMI were enrolled in the two phases of the Determinants of Myocardial Infarction Onset Study a median of four days after admission. Trained interviewers assessed self-reported usual tea and coffee consumption during the year prior to infarction with a standardized questionnaire. We examined the prevalence of ventricular arrhythmias in the two phases of the study separately and together.

RESULTS

Among the 1912 patients with complete information in the first phase, the prevalence of ventricular arrhythmias was 16% among abstainers from tea, 11% among moderate tea drinkers (<14 cups per week), and 14% among heavier tea drinkers (> or =14 cups per week) (p homogeneity = 0.03). Among the 1791 patients with comparable information in the second phase, the corresponding prevalence rates were 11%, 8%, and 8%, respectively (p = 0.06). When the phases were combined, the adjusted odds ratios for VA were 0.7 (95% confidence interval, 0.6-0.9) among moderate tea drinkers and 0.9 (95% confidence interval, 0.7-1.2) among heavier tea drinkers. The findings were of similar direction for both ventricular tachycardia and fibrillation. In contrast, there was higher risk of VA with increasing coffee intake (odds ratio for >14 cups per week 1.3; 95% confidence interval, 1.0-1.7; p trend 0.02).

CONCLUSIONS

Moderate tea intake is associated with a lower prevalence, and higher coffee intake with a slightly higher prevalence, of ventricular arrhythmias among patients hospitalized with acute myocardial infarction. If the association with tea intake is confirmed, it may suggest new approaches to prevention of ischemia-related arrhythmias.

Coffee intake and incidence of hypertension

BACKGROUND

The long-term longitudinal evidence for a relation between coffee intake and hypertension is relatively scarce.

OBJECTIVE

The objective was to assess whether coffee intake is associated with the incidence of hypertension.

DESIGN

This study was conducted on a cohort of 2985 men and 3383 women who had a baseline visit and follow-up visits after 6 and 11 y. Baseline coffee intake was ascertained with questionnaires and categorized into 0, >0-3, >3-6, and >6 cups/d. Hypertension was defined as a mean systolic blood pressure (SBP) >or=140 mm Hg over both follow-up measurements, a mean diastolic blood pressure (DBP) >or=90 mm Hg over both follow-up measurements, or the use of antihypertensive medication at any follow-up measurement.

RESULTS

Coffee abstainers at baseline had a lower risk of hypertension than did those with a coffee intake of >0-3 cups/d [odds ratio (OR): 0.54; 95% CI: 0.31, 0.92]. Women who drank >6 cups/d had a lower risk than did women who drank >0-3 cups/d (OR: 0.67; 95% CI: 0.46, 0.98). Subjects aged >or=39 y at baseline had 0.35 mm Hg (95% CI: -0.59, -0.11 mm Hg) lower SBP per cup intake/d and 0.11 mm Hg lower DBP (95% CI: -0.26, 0.03 mm Hg) than did those aged <39 y at baseline, although the difference in DBP was not statistically significant.

CONCLUSIONS

Coffee abstinence is associated with a lower hypertension risk than is low coffee consumption. An inverse U-shaped relation between coffee intake and risk of hypertension was observed in the women.

Association between coffee consumption and risk of hypertension

BACKGROUND

The longitudinal relationship between coffee use and hypertension is not well known. Aim. We did a prospective study to investigate if there is a temporal relationship between coffee consumption and development of sustained hypertension.

METHOD

We assessed 1107 white subjects with elevated blood pressure who were followed up for 6.4 years. Coffee intake and other life-style factors were ascertained from regularly administered questionnaires. Incident physician-diagnosed hypertension was the outcome measure.

RESULTS

During the follow-up, 561 subjects developed sustained hypertension, whereas 546 subjects did not meet the criteria for treatment. Coffee drinkers developed sustained hypertension more frequently than abstainers (53.1% versus 43.9%, P = 0.007). The incidence of hypertension did not differ between moderate and heavy coffee drinkers. Kaplan-Meier analysis confirmed that sustained hypertension was developed more frequently by coffee drinkers compared with nondrinkers (P<0.001). The adjusted relative risk of hypertension was greater in both categories of coffee drinking than in abstainers (hazard ratio, 95% confidence limit (CL) = 1.24, 1.06-1.44). The risk of hypertension associated with coffee drinking increased gradually with increasing level of alcohol use (adjusted P for interaction = 0.005).

CONCLUSIONS

In subjects screened for stage 1 hypertension a nonlinear association was found between coffee consumption and development of sustained hypertension.

Effect of chronic coffee consumption on aortic stiffness and wave reflections in hypertensive patients

OBJECTIVE

Aortic stiffness and wave reflections are important markers and prognosticators of cardiovascular risk. Caffeine increases acutely aortic stiffness and wave reflections. Furthermore, chronic coffee consumption is associated with increased aortic stiffness and wave reflections in normotensive subjects. In the present study, we aimed to assess the association between chronic coffee consumption, and aortic stiffness and wave reflections in hypertensive patients.

DESIGN

Epidemiological survey.

SETTING

Hypertension Unit, University Hospital. SUBJECTS-METHODS: We examined 259 never-treated hypertensives (age 50+/-12 years, 165 males) without diabetes mellitus, who were asked to describe in detail the type and amount of coffee they consumed. Carotid-femoral pulse wave velocity (PWV) and augmentation index (AIx) were measured non-invasively as indices of aortic stiffness and wave reflections, respectively.

RESULTS

When controlled for gender, age, height, smoking status, heart rate, mean pressure, HDL cholesterol and hsCRP, AIx was found to be higher with increasing daily coffee consumption. Post hoc analysis revealed that all groups of coffee consumption had higher AIx compared to no-consumption. PWV did not differ among groups of daily coffee consumption. Each participant had 35% higher relative risk of having high AIx for each cup (150 ml) of coffee per day, and 40% higher relative risk for each 10 cup-years.

CONCLUSIONS

Coffee consumption is associated with increased wave reflections, but not aortic stiffness in never-treated hypertensive patients. This finding may have important clinical implications for cardiovascular health in hypertensive subjects.

Coffee consumption and markers of inflammation and endothelial dysfunction in healthy and diabetic women

BACKGROUND

In several short-term studies, coffee consumption has been associated with impairment of endothelial function.

OBJECTIVE

The objective was to assess the relation between long-term caffeinated and decaffeinated filtered coffee consumption and markers of inflammation and endothelial dysfunction.

DESIGN

We conducted a cross-sectional study of 730 healthy women and 663 women with type 2 diabetes from the Nurses' Health Study I cohort, who were aged 43-70 y and free of cardiovascular disease and cancer at the time blood was drawn (1989-1990). Dietary intake was assessed with a validated food-frequency questionnaire in 1986 and 1990.

RESULTS

About 77% of the healthy women consumed > or =1 cup (237 mL) caffeinated coffee/mo and 75% consumed > or =1 cup decaffeinated coffee/mo; the corresponding intakes for women with type 2 diabetes were 74% and 63%, respectively. In healthy women, no appreciable differences in plasma concentrations of the markers were found across categories of caffeinated coffee intake. In women with type 2 diabetes, higher caffeinated coffee consumption was associated with lower plasma concentrations of E-selectin (adjusted percentage change per 1 cup/d increment = -3.2%; P = 0.05) and C-reactive protein (adjusted percentage change = -10.2%; P < 0.001). Higher decaffeinated coffee consumption was associated with lower plasma concentrations of E-selectin (adjusted percentage change = -2.5%; P = 0.08) and C-reactive protein (adjusted percentage change = -7.9%; P = 0.02) only in healthy women. The results were similar when we also adjusted the models for other dietary factors and blood lipids and when we excluded participants with hypertension or hypercholesterolemia.

CONCLUSIONS

These results indicate that neither caffeinated nor decaffeinated filtered coffee has a detrimental effect on endothelial function. In contrast, the results suggest that coffee consumption is inversely associated with markers of inflammation and endothelial dysfunction.

Acute Effect of Black and Green Tea on Aortic Stiffness and Wave Reflections

OBJECTIVE

While most studies have shown an inverse relation between tea consumption and cardiovascular risk, other studies have shown opposite results. Aortic stiffness and wave reflections are markers of cardiovascular disease and prognosticators of cardiovascular risk.

METHODS

The acute effect of black and green tea on aortic stiffness and wave reflections was assessed in 29 healthy volunteers in a randomized, single-blind, sham-procedure controlled, cross-over design. In the black tea sub-study, 16 subjects received 6 gm of tea, caffeine (175 mg), or hot water in 3 different sessions. In the green tea sub-study, 13 subjects received 6 gm of tea, caffeine (125 mg), or hot water. Carotid-femoral pulse wave velocity and wave reflection indices were measured at baseline and for 3 hours after consumption.

RESULTS

Black tea increased pulse wave velocity during the first 90 min (increase by 0.49 m/sec, P < 0.05), showing a rapid return towards baseline values thereafter (P = 0.07 for the whole study period); in contrast, green tea had no effect. Both black and green tea increased augmentation index (by 5.0% and by 6.6%, P < 0.01 and P < 0.001, respectively) throughout the study. These changes were less than the respective changes produced by caffeine. Both black and green tea had a significant pressor effect. No change in oxidant status was found with both types of tea.

CONCLUSIONS

Both black and green tea increases acutely wave reflections and only black tea increases aortic stiffness. Tea flavonoids may play a role in the attenuation of the effects of caffeine contained in tea.

Effect of dark chocolate on arterial function in healthy individuals: Cocoa instead of ambrosia?

Cocoa has been consumed for at least 2500 years, and for long time it has been regarded as a medicine. Arterial function is of paramount importance for the proper function and integrity of the cardiovascular system. Dark chocolate and flavonoid-rich cocoa have beneficial acute and short-term effects on endothelial function and wave reflections in normal individuals, in adults with cardiovascular risk factors, and in patients with coronary artery disease. Furthermore, dark chocolate and flavonoid-rich cocoa may have a blood pressure-lowering effect. These effects can be attributed to flavonoids and are mainly mediated through increased nitric oxide bioavailability. Further research is needed to demonstrate whether these effects of chocolate on arterial function are translated into clinical benefit.