Effect of Varied Doses of Coffee-Caffeine on Resting Cardiovascular system of Healthy Black African Adults (original) (raw)
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Cardiovascular effects of coffee and caffeine
The American Journal of Cardiology
This study evaluated the cardiovascular effects and elimination kinetics of coffee and caffeine in 54 volunteers selected according to 3 gradations of daily caffeine consumption, cigarette smoking status and the presence of caffeine intolerance. After 24 hours of caffeine abstinence, subjects received coffee and 2.2 mg/kg of caffeine (equivalent to 2 cups of coffee). Blood pressure, heart rate, systolic time intervals and plasma concentrations of caffeine were measured before and at timed intervals after coffee and caffeine. There were no differences in response to coffee and caffeine. The average systolic/diastolic blood pressure increased 9110 mm Hg. The maximal decrease in heart rate averaged 10 beats/min, and there were small increases in the systolic time intervals. There were no cardiovascular differences among the various groups. Caffeine in the smokers and heavy caffeiire users had a shorter half-life (3.2 and 4.1 hours) than that in nonsmokers and nonusers . in the caffeineintolerant group it had a longer half-life, while the cardiovascular effects were similar to those of the other groups. Thus, irrespective of the amount of daily caffeine consumption, smoking status or caffeine intolerance, the cardiovascular responses were similar and tolerance, if present, was gone by 24 hours.
Caffeine and cardiovascular health
This report evaluates the scientific literature on caffeine with respect to potential cardiovascular outcomes , specifically relative risks of total cardiovascular disease (CVD), coronary heart disease (CHD) and acute myocardial infarction (AMI), effects on arrhythmia, heart failure, sudden cardiac arrest, stroke, blood pressure, hypertension, and other biomarkers of effect, including heart rate, cerebral blood flow, cardiac output, plasma homocysteine levels, serum cholesterol levels, electrocardiogram (EKG) parameters , heart rate variability, endothelial/platelet function and plasma/urine catecholamine levels. Caffeine intake has been associated with a range of reversible and transient physiological effects broadly and cardiovascular effects specifically. This report attempts to understand where the de-lineations exist in caffeine intake and corresponding cardiovascular effects among various sub-populations. The available literature suggests that cardiovascular effects experienced by caffeine consumers at levels up to 600 mg/day are in most cases mild, transient, and reversible, with no lasting adverse effect. The point at which caffeine intake may cause harm to the cardiovascular system is not readily identifiable in part because data on the effects of daily intakes greater than 600 mg is limited. However, the evidence considered within this review suggests that typical moderate caffeine intake is not associated with increased risks of total cardiovascular disease; arrhythmia; heart failure; blood pressure changes among regular coffee drinkers; or hypertension in baseline populations.
Acute effects of coffee on QT interval in healthy subjects
Nutrition Journal, 2011
The coronary endothelial function is recognized to have an important role in the physiology of the diastolic ventricular relaxation, a phase of the heart cycle that influences the electrocardiographic QT interval. Endothelial function is investigated in vivo by flow mediated dilation (FMD) in the brachial artery and has proven to be a strong predictor of both coronary endothelial function and cardiovascular events. It has been reported that coffee acutely induces FMD changes. In particular, the brachial artery FMD seems to decrease after caffeinated coffee (CC) and to increase after decaffeinated coffee (DC) ingestion. Since the cardiovascular effects of coffee are still a debated matter, this study aimed at investigating with a randomized, double-blind crossover design, if the QT interval of adult healthy subjects (19 males and 21 females) changes in the hour following CC or DC ingestion. Both systolic and diastolic blood pressure were higher in the hour following the ingestion of CC; the heart rate significantly increased 30 minutes after CC ingestion. A significant increase of the QT duration was observed one hour after DC ingestion (398.9 ± 3.8 vs 405.3 ± 3.7 msec; P < 0.05), not after CC. The QT interval corrected for heart rate did not significantly change following CC or DC ingestion. In conclusion, despite CC and DC previously demonstrated to influence the FMD they do not seem to induce a significant unfavourable acute change of the left ventricular repolarization. Further investigations are required to elucidate the effects of coffee in subjects with cardiovascular diseases.
Effects of caffeine on vascular resistance, cardiac output and myocardial contractility in young men
American Journal of Cardiology, 1985
The mechanisms by which caffeine typically elevates blood pressure (BP) in humans have not been previously examined using a placebo-controlled design. Accordingly, oral caffeine (3.3 mg/kg body weight, equivalent to 2 to 3 cups of coffee) was given on 2 days and a placebo was given on 1 day to 15 healthy young men using a double-blind, crossover procedure. All 3 test sessions were held during a week of caffeine abstinence. Multiple measurements were made on subjects at rest (baseline values) and over a 45minute interval after ingestion of caffeine for BP, heart rate, systolic time intervals and thoracic impedance measures of ventricular function. Baseline measurements were highly reliable for each subject across all sessions and yielded means for placebo vs caffeine days that were not different. Caffeine increased systolic and diastolic BP (p <O.Ol) and decreased heart rate (p <0.05). The pressor effect was due to progressively increased systemic vascular resistance and resulted in greater stroke work (p <O-01). There was no indication that caffeine increased cardiac output or contractility. These actions of caffeine were replicable when each caffeine day was tested separately against the placebo day. These results suggest that caffeine use by persons with cardiovascular diseases should be examined to determine whether caffeine's enhancement of vascular resistance may contribute to systematic hypertension and/or create excessive demands for cardiac work.
National Journal of Medical Research, 2013
Introduction: Coffee is one of the most widely consumed beverages in the world. It is the primary source of caffeine in many populations, but also contains several other biologically active components that may have either harmful or beneficial cardiovascular effects. Caffeine is widely consumed by people of all ages in India as well as many other countries. Methods: The study was conducted on 80 volunteers aged 21-40 years and with body mass index (BMI) between 17.3-28.0 kg /m2 .The subjects were divided into two groups: Control (n=40) (Age less than 25years )and Study group (n=40)(Age > 40 years). Results: Observation suggests that increment in systolic blood pressure (SBP) recorded in both the groups after coffee ingestion, but SBP increment was lesser in elderly person than that of control group. We also observe that there was decrease in heart rate in both study and control group, QTc was lower in control group. Conclusion: Coffee increases systolic and diastolic blood pressure but not the heart rate and the QTc interval. we also conclude that QTc interval is greater in elderly persons.
Cardiovascular effects of caffeine in men and women
The American Journal of Cardiology, 2004
Caffeine increases blood pressure (BP). In men, acute BP elevations after caffeine intake are due to an increase in vascular resistance, with no change in cardiac output. The hemodynamic effects of caffeine have not been studied in women. Accordingly, BP and hemodynamic responses to caffeine were measured in a double-blind trial comparing age-matched men and women at rest and during mental stress. Caffeine (3.3 mg/kg, equivalent to 2 to 3 cups of brewed coffee) or placebo was given to separate groups of women (n ؍ 21 and 21) and men (n ؍ 16 and 19) (mean ages 29 and 27 years, respectively). BP, cardiac output, and vascular resistance were observed at rest, during a stressful public-speaking simulation, reading aloud, and recovery. Caffeine caused nearly identical systolic and diastolic BP elevations in women (4.5 and 3.3 mm Hg, respectively) and men (4.1 and 3.8 mm Hg, respectively). Men given caffeine versus placebo showed the expected elevation in vascular resistance throughout the remainder of the protocol (p <0.001), with no difference in cardiac output. In contrast, women responded to caffeine with increases in stroke volume (p <0.001) and cardiac output (p <0.001), with no difference in vascular resistance from women taking placebo. Men and women have similar BP responses to caffeine, but the BP responses may arise from different hemodynamic mechanisms. Women who consume a dietary dose of caffeine showed an increase in cardiac output, whereas men showed increased vascular resistance. ᮊ2004 by Excerpta Medica, Inc.
Impact of coffee consumption on heart health: An Overview
International Journal of Cardiology Sciences, 2024
Communicating with evidence indicates that coffee consumption improves heart health, but a cautionary approach is recommended for individual differences. Bioactive compounds present in coffee such as polyphenols and diterpenes have antioxidant and anti-inflammatory properties that may positively affect vascular health. Nonetheless, there is a synthesis of epidemiological, clinical, and mechanistic studies undertaken on this subject. According to epidemiologic studies, moderate coffee consumption (3-5 cups) is inversely related to the risk of developing and dying from a number of cardiovascular conditions including coronary artery disease, stroke, and heart failure. However, it is important to note that too much of a good thing can have negative effects; those who are sensitive to caffeine or partake in excess consumption may experience arrhythmias, high blood pressure, or rapid heartbeats. It is also important to understand that the effects of coffee on heart health are influenced by lifestyle factors, genetic factors, and brewing techniques, and vice versa: coffee’s impact on heart health is a two-way street. Lastly, given the various benefits and risks that accompany coffee consumption, the review calls for tailored recommendations. To aid in gathering complete information and better serve the general public, further research must address the multifaceted relationships between coffee components, genetic predispositions, and cardiac events.
Coffee, caffeine and blood pressure: a critical review
European Journal of Clinical Nutrition, 1999
Objective: We review the published data relating to intake of coffee and caffeine on blood pressure in man. We also refer to studies on the possible mechanisms of actions of these effects of caffeine. Design: The MEDLINE and Current Contents databases were searched from 1966 to April 1999 using the text words`coffee or caffeine' and`blood pressure or hypertension'. Controlled clinical and epidemiologic studies on the blood pressure effects of coffee or caffeine are reviewed. We also refer to studies on the possible mechanisms of action of these effects of caffeine. Results: Acute intake of coffee and caffeine increases blood pressure. Caffeine is probably the main active component in coffee. The pressor response is strongest in hypertensive subjects. Some studies with repeated administration of caffeine showed a persistent pressor effect, whereas in others chronic caffeine ingestion did not increase blood pressure. Epidemiologic studies have produced contradictory ®ndings regarding the association between blood pressure and coffee consumption. During regular use tolerance to the cardiovascular responses develops in some people, and therefore no systematic elevation of blood pressure in long-term and in population studies can be shown. Conclusions: We conclude that regular coffee may be harmful to some hypertension-prone subjects. The hemodynamic effects of chronic coffee and caffeine consumption have not been suf®ciently studied. The possible mechanisms of the cardiovascular effects of caffeine include the blocking of adenosine receptors and the inhibition of phosphodiesterases.
Coffee Consumption and Cardiovascular Risk: An Updated Overview
Journal of Cardiology and Therapy, 2014
Coffee is one of the most widely consumed beverages worldwide. Since coffee contains caffeine, a stimulant, coffee drinking is not generally considered to be part of a healthy lifestyle. However, coffee is a rich source of antioxidants and other bioactive compounds, and many misconceptions persist regarding the health-related effects of coffee. Because of coffee is a complex beverage containing many bioactive compounds, its biological effects may be substantial and are not limited to the actions of caffeine; consequently, the health effects of chronic coffee intake are wide ranging. Coffee consumption may reduce the risk of type 2 diabetes mellitus, hypertension, obesity and depression, but it may adversely affect lipid profiles depending on how the beverage is prepared. A growing body of evidences suggests that habitual coffee consumption is neutral to beneficial regarding the risks of a variety of adverse cardiovascular outcomes including coronary heart disease, congestive heart failure, arrhythmias, and REVIEW
Journal of the American College of Cardiology, 2013
Coffee is the most widely consumed beverage in the United States (US) after water, and is the principal source of caffeine intake among adults. The biological effects of coffee may be substantial and are not limited to the actions of caffeine. Coffee is a complex beverage containing hundreds of biologically-active compounds, and the health effects of chronic coffee intake are wide ranging. From a cardiovascular (CV) standpoint, coffee consumption may reduce the risks of type 2 diabetes mellitus (T2DM) and hypertension (HTN), as well as other conditions associated with CV risk such as obesity and depression; but it may adversely affect lipid profiles depending on how the beverage is prepared. Regardless, a growing body of data suggests that habitual coffee consumption is neutral to beneficial regarding the risks for a variety of adverse CV outcomes including coronary heart disease (CHD), congestive heart failure (CHF), arrhythmias, and stroke. Moreover, large epidemiological studies suggest that regular coffee drinkers have reduced risks for mortality-both CV and all-cause. The potential benefits also include protection against neurodegenerative diseases, improved asthma control, and lower risk of select gastrointestinal diseases. A daily intake of about 2 to 3 cups of coffee appears to be safe and is associated with neutral to beneficial effects for most of the studied health outcomes. However, most of the data on coffee's health effects are based upon observational data, with very few randomized controlled studies, and association does not prove causation. Additionally, the possible advantages of regular coffee consumption have to be weighed against potential risks (which are mostly related to its high caffeine content) including anxiety, insomnia, tremulousness and palpitations, as well as bone loss and possibly increased risk of fractures.