One of coffee’s most famous health benefits can be reversed if you consume more than 400 mg of caffeine per day.
A new study presented at the American College of Cardiology Asia 2024 (ACC Asia 2024) conference found that coffee is only good for your health when consumed in moderation.
The research, led by Dr. Nency Kagathara from Zydus Medical College & Hospital (India), focused on coffee’s most well-known benefit: its effects on the cardiovascular system.
Many earlier studies have shown coffee to be a “miracle drink” for the heart. Drinking a few cups a day has been linked to better blood pressure control and a lower risk of serious heart conditions.
However, the new findings warn that consuming about 400 mg of caffeine daily can cause problems.
A typical cup of coffee contains about 80–100 mg of caffeine, depending on how it is brewed. That means 400 mg is roughly equivalent to four strong cups of coffee or five weaker cups. The same amount of caffeine can also be found in about 10 cans of regular soda or 2 cans of energy drinks.
In a detailed analysis of volunteers aged 18–45, researchers found that when high caffeine intake is maintained daily, it can disrupt the parasympathetic nervous system, leading to higher blood pressure and faster heart rate, even in young, healthy adults.
For those who consume more than 600 mg of caffeine per day, heart rate and blood pressure remained significantly elevated even five minutes after resting following a walking test.
Previous research has shown that with moderate coffee consumption, blood pressure may rise temporarily right after drinking, but it quickly returns to normal. Over time, drinking a few cups a day can even help the body regulate blood pressure more effectively.
But when caffeine intake is too high, the body struggles to recover, putting long-term heart health at risk.