Up to 5 Cups of Coffee a Day Is Safe for Most Adults, Says American Heart Association

If you're someone who enjoys multiple cups of coffee every day, new research offers reassuring news.

A scientific statement released by the American Heart Association (AHA) says that most healthy adults can safely consume up to 400 mg of caffeine per day—roughly equivalent to five 8-ounce cups of caffeinated coffee—without increasing their risk of cardiovascular disease.

Published in the peer-reviewed journal Circulation, the statement reviews the latest scientific evidence on caffeine and heart health. Researchers found that moderate coffee consumption, especially black coffee without added sugar or cream, may even be associated with a lower risk of several cardiovascular conditions.

"Caffeine consumed in coffee is a key part of daily life for millions of people, and in our review of the most recent research, for most adults, intake of up to 400 mg of caffeine/day, the equivalent of up to 5 cups of caffeinated coffee per day without added sugars or fillers, is safe and does not increase cardiovascular risk," said Gregory M Marcus, MD, MAS, FAHA, chair of the scientific statement writing group and professor of medicine at the University of California, San Francisco.

He added, "However, high doses of caffeine, such as those found in energy drinks including energy shots, may have harmful effects on the heart and should be avoided."

Can coffee actually benefit your heart?

According to the review, drinking two to four cups of caffeinated coffee a day has been associated with a lower risk of heart disease, heart failure and stroke.

The researchers also found that black coffee consumed without additives may be linked to a reduced risk of Type 2 diabetes, stroke, heart disease, heart failure and certain irregular heart rhythms.

However, the benefits appear to have limits. The review notes that drinking more than four cups a day may increase the risk of heart failure in some individuals.

Randomised clinical trials also suggested that caffeine in coffee may reduce the risk of atrial fibrillation, while increasing the likelihood of premature ventricular contractions (PVCs), highlighting that caffeine's effects can vary depending on the type of heart rhythm.

Why are energy drinks viewed differently?

The AHA statement draws a clear distinction between coffee and energy drinks.

Researchers found that energy drinks and energy shots often contain much higher concentrations of caffeine—between 40 and 69 mg per fluid ounce—compared with 9.4 to 20.6 mg per fluid ounce in regular brewed coffee.

These highly concentrated beverages have been linked to increased blood pressure and abnormal heart rhythms, making them a less favourable source of caffeine.

What factors influence how caffeine affects you?

The researchers stress that there is no universal caffeine recommendation that suits everyone.

Factors such as genetics, age, medications, metabolism and regular caffeine intake all influence how the body responds.

In the short term, caffeine can temporarily raise blood pressure, heart rate and blood sugar while also improving alertness. Some people may also experience heart palpitations, anxiety or sleep disturbances.

Marcus emphasised that moderation and individual tolerance remain important.

"Although research suggests that caffeine consumption may be associated with certain cardiovascular benefits for some people, it's important to remember that there is no 'one-size-fits-all' strategy for safe caffeine consumption. People can respond very differently to caffeine based on various factors, such as age, medications, underlying health conditions, genetics and how quickly their bodies metabolize it. What may be a reasonable amount for one person could cause unwanted effects, such as heart palpitations, anxiety or sleep disruption, in another. That's why it's important to pay attention to how your body responds to caffeine and talk with your healthcare team about what is right for you," he said.

What are the limitations of the research?

The authors caution that much of the available evidence is based on observational studies, meaning the findings show associations rather than direct cause and effect.

They also note that coffee contains many naturally occurring compounds besides caffeine, making it difficult to isolate caffeine's specific effects. In addition, ingredients commonly added to coffee—such as sugar, flavoured syrups, milk and cream—can significantly influence health outcomes.

The American Heart Association says more randomised controlled trials are needed to better understand how caffeine from different sources, including tea, soft drinks, energy drinks and supplements, affects cardiovascular health and why people respond differently.

(With inputs from ANI)