How Does Caffeine Affect Your Heart
You wake up and brew yourself a pot of coffee. As you sit to read the morning news, you start sipping, getting ready to start the day. Later in the afternoon, you feel the post-lunch slump, so you drive to the nearest coffee shop for a pick-me-up espresso or latte. But have you ever wondered how the caffeine in all this coffee affects your body more specifically, your heart? Lets break it down.
How Does Caffeine Affect Heart Rate
Caffeine is a natural psychostimulant, a substance that affects the central nervous system . Considering the fact that we consume it daily by drinking coffee, tea and cola, it’s no wonder why people call it the world’s most famous psychoactive drug. Naturally, it can be found in leaves and seeds of many plants. Out of many physiological effects that caffeine has on the human body, one of the most important ones must be its effect on heart rate.
Is Caffeine Bad For Your Heart
New Research Suggests Caffeine Elevates Blood Pressure, Stress
Aug. 1, 2002 — Like millions of Americans, self-described coffee addict Kathy Liebswager can’t quite function in the mornings until she has had her caffeine fix. She typically drinks eight to 10 cups throughout the day, and she says she believes the caffeine has a calming effect on her.
“When I worked, I literally couldn’t think until I had had my first cup of coffee,” the retired Navy counselor says. “There have been periods when I cut way down or mixed decaffeinated coffee with regular, but I definitely missed the caffeine.”
Liebswager is not alone in thinking of caffeine as a stress reliever, but a new study suggests the opposite is true. Researchers at Duke University Medical Center found that caffeine actually exaggerates stress and its effect lasts throughout the day.
Even more troubling, the researchers concluded that the equivalent of four cups of coffee raises blood pressure for many hours. Although the increases appear modest, they are large enough to affect heart attack and stroke risk, says lead author James D. Lane, PhD. The findings were reported in the July/August issue of the journal Psychosomatic Medicine.
Caffeine is consumed daily by an estimated 85% of adults in the U.S. in the form of coffee, tea, and sodas. The average daily number of cups per coffee drinker is 3.3, and 64% of all coffee is consumed at breakfast.
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Aspect : Defining The Problem And Selecting Variables
Background Information: The human heart is a major muscular organ located in the thoracic cavity between the lungs. Its major function is to pump blood throughout the body. A double-layered sac, Pericardium, which is the tough connective tissue protects and anchors the heart. There is fluid between the layer of the sac allow for lubrication of the hearts continual motions. The inner layer of the sac is the heart wall, which is mainly cardiac muscle. The human heart is made up of two chambers. The atriums receive blood from veins, and the ventricles pump blood into the arteries. For the blood to pass through the an atrium to a ventricle for example, the blood has to pass through a heart valve. Valves control the blood from moving backwards. The lub-dub sound made by a beating heart derives from the closing of the atrioventricular valves, then the concurrent closing of the aortic and pulmonary valves . The human heart is also myogenic meaning the heart is independent of an outside stimulus from the nervous system. The sinoatrial node, pace maker, is responsible for sending electrical impulses through the heart making it contract and pump blood. The human heart is very much affected by the consumption of caffeine. Caffeine can be found in certain coffees, teas, sodas, and chocolates. By consuming caffeine ones heart rate to dramatically increase and also cause abnormal heart rhythms .
Variables
Caffeine Dependency And Withdrawal
Like many other drugs, its possible to build up a tolerance to caffeine. This means you become used to its effects on your body and need to take larger amounts to achieve the same results. Over time, you may become physically and psychologically dependent on caffeine to function effectively.
If you are dependent on caffeine and you stop having it, you may experience withdrawal symptoms. These may include:
- fatigue
- muscle pain
- anxiety.
Symptoms of caffeine withdrawal may begin within 12 to 24 hours and can last about seven days.
The easiest way for you to break caffeine dependence is to reduce the amount youre having gradually. This gives your nervous system time to adapt to functioning without the drug.
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Coffee Caffeine And Your Heart: Q& a With Dr Arrash Fard
Dr. Arrash Fard is here to answer all our questions about coffee and caffeine consumption, particularly for people with heart conditions like hypertension or heart disease.
Q: In general, there’s a lot of conflicting information out there about how coffee affects the heart . What’s your advice for those who either have a condition like heart disease or hypertension, or are at risk for developing one later in life, when it comes to interpreting all the contradictory research out there about coffee and heart health?
A: There is no strong evidence that coffee consumption has deleterious effects on heart health when consumed in modest amounts. To go further, medical literature does not support concerns of modest coffee intake on cardiac outcomes such as death or stroke. It is generally accepted as safe for most healthy adults to consume less than 400 mg of caffeine daily. It is generally not recommended for people to discontinue coffee or caffeine intake to try improving cardiovascular outcomes.
Q: Coffee aside, what should people with chronic heart-related conditions/people who are at risk of these conditions know about general caffeine use? Are there more risks/benefits associated with different forms of caffeine ?
Evidence Of Coffees Heart Benefits
A Harvard University study published in Circulation in 2015 found that people who drank three to five cups of coffee daily were less likely to die prematurely from any cause. It also found that they were specifically less likely to die from heart disease and stroke compared to people who drank little or no coffee. And drinking more than five cups of coffee per day didnt favorably affect risk of death.
These are just the latest in a string of positive research findings. For example, an analysis published in 2013 in Circulation compiled the results of 36 studies on coffee that included more than one million patients. Researchers concluded that people who drank coffee in moderation were significantly less likely to develop cardiovascular disease than those who didnt drink coffee. Again, the review showed that three to five cups offered the greatest level of protection. Additionally, an analysis published in 2012 in Circulation: Heart Failure of five clinical studies, including more than 140,000 patients, found that those who drank four cups of coffee daily were least likely to develop heart failure.
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Caffeine And Risk Of Arrhythmia
Presented by Jeffrey Goldberger, M.D., NorthwesternUniversity
A 1994 survey of several hundred physicians from Minnesota and Vermont foundthat 94 percent of those surveyed recommended reducing or stopping caffeinefor patients complaining of palpitations . Jeffrey Goldbergerdescribed the finding as remarkable and considered it histask for the workshop to examine whether the evidence supports thatrecommendation. In his experience, it is not often that 94 percent ofphysicians agree on something even when its benefits have been demonstratedin randomized clinical trials, such as the use of beta-blockers aftermyocardial infarction or anticoagulants for atrial fibrillation. It isdifficult to get that kind of consensus and interesting to consider where itcomes from.
There are many data sources on the effects of caffeine on arrhythmias,including case reports, animal studies, human physiologic studies, humansmall-case series, and human observational trials. The predominant focus ofGoldberger’s presentation was on human observational trials. He notedthat most of the data comes from coffee-intake studies and emphasized theneed to keep in mind, while reviewing these studies, the variation in theamount of caffeine in different coffee drinks.
Differences Between Caffeine In Energy Drinks Versus Coffee
One audience member disputed El-Sohemy’s claim that peakconcentrations from chugging a cold drink are different from those fromslowly sipping a hot beverage. According to the audience member, thedose response is the same for similar doses regardless of whether thedose is being consumed slowly or quickly. El-Sohemy replied that theactual dose, the actual amount of caffeine being consumed, is not theonly issue. In terms of peak plasma concentrations, which can haveimportant physiological effects, chugging a cold beverage leads to ahigher peak plasma concentration and could have a profound effect evenif the dose is smaller than the dose in a hot beverage sippedslowly.
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What Happens To The Heart When You Consume Caffeine
Once you take that first sip of coffee, the caffeine enters your blood from the stomach and small intestine and begins to stimulate your central nervous system. The receptors in the cells within your heart are stimulated by the caffeine and increases your heart rate.
As your heart beats faster accelerating by about three beats per minute your blood flow speeds up, too. The increase in your heart rate from caffeine can take effect in as soon as 15 minutes and take approximately six hours to wear off.
Benefits Of Caffeine: How Caffeine Improves Brain Function And Activity
Ishtiak Ahmed Chowdhury
Tags: Brain, Brain activity, Brain function, Dopamine, Serotonin, Adenosine antagonist, Coffee benefits, Caffeine benefits, Benefits of caffeine, Psychoactive drug
Take a guess! What do you think is the most popular psychoactive drug in the whole wide world?!
Coffee has been the staple non-alcoholic beverage of America since Captain John Smith, the founder of the first English settlement: colony of Virginia, introduced it here after his visits to Turkey. Back then in 1607, John Smith had no idea of what he had just accomplished!
Captain John Smith had introduced America to a substance so powerful that it would go on to become the most dominant psychoactive drug of the 21st century. Although times have changed and caffeine is not just available in coffee or tea it has also become available in various other edible forms. Energy drinks and energy shots are highly enriched with caffeine along with Taurine, an amino acid that is ubiquitously found in the human body.
However, the burning question is: does caffeine have a positive effect on the human brain?
Believe it or not, caffeine drastically improves brain function and activity. Although caffeine can induce dependence and high tolerability in moderation, it has tremendous benefits.
In summary, caffeine certainly has a positive effect on productivity as it improves brain function and activity. However, it must be administered in moderation.
References:
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Panelist Discussion With The Audience
Following El-Sohemy’s presentation, workshop participants were invitedto ask questions of the three panelists. Most of the discussion revolvedaround the future research needs on the cardiovascular effects of caffeineexposure, including in vulnerable populations, and differences betweencaffeine in energy drinks versus coffee.
Human Studies On The Effect Of Caffeine On Arrhythmias And Othercardiac End Points
Many health effects that are observed in association with caffeineexposure are those that occur on sympathetic excitation, according toGoldberger. examined the effect of coffee on sympathetic nerveactivity in a placebo-controlled trial of 15 healthy volunteers . A number of interventionswere tested, including intravenous caffeine versus placebo anda triple espresso versus a decaf triple espresso . The researchers reported a sustained increase in caffeine levelsin the intravenous caffeine group and, not surprisingly inGoldberger’s opinion, a small increase in blood pressure and adrop in heart rate. Sympathetic nerve activity, as measured by a numberof different techniques, also increased. The placebo group showed nochange over time. With coffee drinking, there was no difference betweenhabitual versus nonhabitual coffee drinkers with respect to sympatheticnerve activity or caffeine levels. A striking finding, inGoldberger’s opinion, was that decaf administered to nonhabitualusers increased blood pressure and sympathetic nerve activity. Habitualusers showed no increase in blood pressure.
More broadly, there are studies that have examined other cardiovascularoutcomes, some of which have shown negative outcomes in association withcaffeine use and others positive outcomes. For example, ,a health professional’s follow-up study, reported lower rates ofcoronary heart disease with caffeine consumption. But other studies haveshown the opposite, according to Goldberger.
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Physiologic Effect Of Coffee
Heart minute volumes and cardiac index rise acutely after coffee consumption, an effect which may in part be due to direct stimulation of cardiac myocytes or central and humoral activation. The effect of caffeine is more pronounced in subjects who do not drink coffee regularly compared with habitual coffee drinkers, who show minimal effects on the CV system. Tolerance to coffee is of clinical importance and should be considered in the assessment of coffee consumption as a CV risk factor.
The acute CV effects of coffee are most likely related to the antagonistic binding of caffeine on adenosine receptors, which results in vasoconstriction and an increase in peripheral resistance. This response may explain the observed rise in diastolic blood pressure compared with systolic BP. Moderate doses of coffee have been shown to reduce resting heart rate due to a moderate increase in BP. The decrease in heart rate is generally associated with vagally mediated slowing as the baroreceptors respond to BP elevations after caffeine administration. Higher doses can produce heart rate acceleration, but such effects are not commonly associated with typical patterns of consumption. The underlying mechanisms for the effect of coffee on the CV system have not been elucidated.
Coffee has a favorable effect both on autonomic failure hypotension and postprandial hypotension and has been recommended as a preventive or therapeutic measure in these conditions.
How Much Caffeine Is Too Much
In New Zealand, there are no firm guidelines on how much caffeine is too much for the general population. For children and pregnant or breastfeeding women there are strict caffeine guidelines. For children its recommended to have no more than 3mg of caffeine per kg of bodyweight. For pregnant and breastfeeding women, its recommended they limit caffeine to 200mg or less a day from all sources.
Although there is a lack of guidelines, there is a recommended maximum daily caffeine intake.
For adults who are not pregnant or breastfeeding this equates to a maximum of 400mg of caffeine per day and no more than 200mg in one sitting. As food and drink sources of caffeine can vary, so does the caffeine content. Depending on the product and size, 400mg can add up quickly.For example, a cup of coffee tends to have more caffeine than a cup of tea, but this also varies between the type of beans and how they are prepared.
- Caffeine in brewed coffee can range between 95200mg per cup.
- Instant coffee can range from 27173mg per cup.
- Black tea contains between 40120mg per cup.
- Green tea between 25-29mg per cup.
For tea, the amount of caffeine depends on how much water it is brewed in, how long its brewed for and the quality of the tea.
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Mouth Throat And Other Cancers
In a study of 968,432 men and women, participants who drank than 4 cups of coffee a day had a 49-percent lower risk of death from oral cancer, compared with those who drank no coffee at all or only an occasional cup.
Other possible cancer-related benefits include:
- a lower risk of endometrial cancer
- a reduced risk of prostate cancer
- protection against head and neck cancer
- protection against the recurrence of breast cancer
If You Are Sensitive To Caffeine You May Want To Be More Cautious
According to the FDA, a fast heart rate, jitters, insomnia, anxiousness, nausea, and headache are common indicators that you are sensitive to caffeine or may have consumed too much.
Those with an arrhythmia, or an irregular heart rhythm, may be more sensitive to caffeine’s effects on heart rate, and can be more likely to feel heart palpitations or fluttering from drinking coffee, says Khan.
A 2018 review published in JACC: Clinical Electrophysiology concluded that avoiding caffeine is only necessary when there’s a clear association between caffeine intake and arrhythmia. However, everyone processes caffeine differently, and even though moderate consumption is deemed safe, the amount you should drink is highly dependent on how your body responds.
“I usually advise patients to listen to their body, and if they feel fluttering and jitters after caffeine intake, I tell them to avoid it,” says Khan, adding that he’s had patients report fewer symptoms after decreasing caffeine consumption.
In addition, pregnant women should be more cautious with caffeine intake, as some studies have found that even moderate consumption can be associated with harmful birth outcomes. The American Pregnancy Association recommends consuming no more than 200 mg per day.
Overall, moderate caffeine intake is considered safe for your heart, and drinking a few cups of coffee may even have cardiovascular benefits. But if you are sensitive to caffeine or consuming too much, it’s best to exercise caution.
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Coffee Can Affect Your Heart’s Rhythms
HealthDay Reporter
MONDAY, Nov. 15, 2021 — Your daily cup of joe might be a quick pick-me-up, but it comes with a mixed bag of good and not-so-good effects on your health, a new study reports.
Drinking coffee helps people stay more active, but it also significantly robs some of sleep, researchers say.
And while java doesn’t seem to cause irregular rhythms in the upper chamber of the heart, it can cause the lower chambers to skip beats, according to findings presented Sunday at the online annual meeting of the American Heart Association.
“People should understand that this extremely commonly consumed beverage really does have substantive effects on our health, and they’re variable,” said lead author Dr. Gregory Marcus, associate chief of cardiology for research at the University of California, San Francisco. “It’s not that coffee is necessarily all good or all bad. It’s very likely that whether it’s net good or net bad depends on a combination of factors.”
Physicians have long considered caffeine a potential heart health risk, since it is a stimulant that increases heart rate. But prior studies on the subject have produced results that were “all over the place,” said Dr. Sana Al-Khatib, a Duke heart rhythm expert.
“It hasn’t been easy for us as clinicians to advise patients,” noted Al-Khatib, who wasn’t involved with the study.
Over two weeks, participants were randomly assigned on a daily basis to either drink as much coffee as they liked or to forgo it.
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