28-year-old dies of heart attack, mother blames caffeine in energy drinks and coffee: How much caffeine is a risk factor?

Why excessive caffeine shots are bad for your heart

Caffeine is a stimulant that promotes the release of stress hormones like noradrenaline. These increase heart rate and blood pressure, stress out your heart by making it work harder. This often leads to arrhythmia or irregular heartbeats, which interfere with the normal functioning of the heart’s electrical signals, causing them to slow down, pace up or simply move in an uncoordinated manner. This may result in stoppage of the heart or what is called as sudden cardiac arrest. Some arrhythmias, like atrial fibrillation (AFib), can lead to blood pooling in the heart’s chambers, increasing the risk of blood clots. If this clot goes to a heart artery, it can cause a heart attack. Prolonged or severe arrhythmias can weaken the heart muscle, making it less efficient at pumping blood. This can lead to heart failure and increase the risk of heart attack.

Does scientific literature bear out the extra caffeine link?

A study presented at the American College of Cardiology’s ACC Asia 2024 conference found that chronic high caffeine consumption (400 mg or more daily) may increase the risk of cardiovascular disease in otherwise healthy individuals. A 1999 study reported that ingesting more than 10 cups of coffee per day was associated with an increased risk of sudden cardiac death in a population with coronary artery disease.

A Japanese study in 2022 found that drinking two or more cups of coffee a day was associated with twice the risk of death from cardiovascular disease among people with severe hypertension compared to non-coffee drinkers.

How much caffeine is safe for the heart?

Up to 400 milligrams (mg) of caffeine per day is generally considered safe for most healthy adults. But studies have shown that having half to one cup of coffee a day is safer because of its antioxidant properties that help in lowering blood sugar and cholesterol. Consuming more than 400 mg of caffeine daily can elevate heart rate and blood pressure. Trouble is not so much about drinking coffee per se but energy drinks and sodas which pack higher concentrations of caffeine, sometimes caffeine equivalent to four cups of coffee. Regular consumption makes you tolerant and addicted to these drinks. So over time, your caffeine intake surpasses normal limits.