The Coffee Consensus

 “We want to do a lot of stuff; we’re not in great shape. We didn’t get a good night’s sleep. We’re a little depressed. Coffee solves all these problems in one delightful little cup.”  The quote, from Jerry Seinfeld, noted comedian and the star of “Comedians in Cars Getting Coffee”, demonstrates just how much people cherish and depend on their coffee. From cafes in Paris to Starbuck’s in Seattle, people all over the world really love their coffee. Coffee is the main source for caffeine, but other products certainly contain caffeine including tea, chocolate and energy drinks.  Is caffeine consumption good or bad for the heart?

Caffeine is known to increase adrenaline and other stimulating hormones in the blood which are part of the “fight or flight” response of the body. These stimulating hormones may provoke arrhythmias (abnormal heart rhythms).  For years doctors have been taught to ask patients about their social habits, including their consumption of caffeine.  In patients with arrhythmias, guidelines state that doctors should try to eliminate potential causative factors including caffeine, alcohol and nicotine.  Does caffeine provoke arrhythmias? Multiple studies have now shown that moderate consumption of caffeine (coffee, tea, chocolate) is not associated with an increased risk for arrhythmias including extra beats from the heart’s upper chambers (premature atrial contractions or PACs), extra beats from the lower chambers (premature ventricular contractions or PVCs), rapid rhythms from the upper chambers (supraventricular tachycardia, SVT, or atrial fibrillation, Afib) and arrhythmias from the lower chambers (ventricular tachycardia, VT).  Even in patients right after a heart attack who were drinking up to five to six cups of coffee a day, there was no increase in the frequency or severity of arrhythmias.

Regular coffee consumption has been associated with a lower risk of diabetes, obesity, depression and heart artery disease.  Caffeine intake has also been shown to lower the risk for cardiac death. The lowest risk for cardiovascular disease was seen in those who drank 3-5 cups of coffee per day and even in heavy coffee drinkers (greater than 5 cups per day) there was no increase in heart disease.  In addition, there is little evidence that chronic coffee consumption raises blood pressure or cholesterol levels.

Chocolate and tea may have additional heart protective benefits due their high content of flavonoids. Flavonoids have antioxidant properties and increase nitric oxide, which helps protect the inner lining of the blood vessels, leading to better cardiovascular health.  Eating flavonoid-rich dark chocolate has been shown to lower blood pressure. Chocolate consumption has also been associated with a lower risk of heart artery disease. A large study of 158,000 people followed over 12 years showed that chocolate consumption, including both dark and milk chocolate, lowered the risk for heart attack, stoke and cardiac death.

Energy drinks, on the other hand, contain a large amount of caffeine (up to three times the amount compared to a cup of coffee) as well as other ingredients (taurine, guarana) which may be harmful for the heart.  In addition, energy drinks are often consumed along with alcohol or just before exercise, increasing their heart risk.  As the usage of energy drinks increases, it is becoming clear that they are dangerous. There were more than 20,000 emergency room visits related to the adverse effects of energy drinks in 2011.  These adverse events include arrhythmias, chest pain, high blood pressure and sudden cardiac death.  The adverse events occurred both in patients with underlying heart disease and, more ominously, without prior heart disease.

Currently, it is felt that moderate coffee consumption is generally safe for the heart and that there may be potential cardiovascular benefits to caffeinated products such as coffee, tea and chocolate.  While some caffeine ingestion appears to be beneficial, the risk for heart problems increases in those who regularly consume energy drinks. This is consistent with the theme that if a moderate amount of something is good for the heart then more is not necessarily better. This is true for caffeine as well as diet, exercise and alcohol. While a cup of coffee per day, moderate exercise, a balanced diet and a glass of wine may be part of a healthy lifestyle, excess caffeine, extreme dieting, chronic obsessive over exercising and binge drinking have all been shown to be harmful.  So enjoy that morning cup of coffee. Moderation is good.