Coffee may protect your heart but energy drinks could harm it Moderate coffee may help the heart, but high-powered energy drinks could push caffeine into dangerous territory. - Date: - July 21, 2026 - Source: - American Heart Association - Summary: - For most adults, a daily caffeine habit may be safer for the heart than many people assume. A new American Heart Association review found that up to 400 milligrams of caffeine a day, roughly three to five cups of regular black coffee, is generally safe and may even be linked to lower risks of heart disease, stroke, heart failure, and Type 2 diabetes.

But the source matters: highly concentrated energy drinks and shots can sharply raise blood pressure and trigger irregular heart rhythms. - Share: Caffeine is the most widely used stimulant and psychoactive substance in the world, and coffee is how most people consume it. According to a new scientific statement from the American Heart Association, most adults can safely consume up to 400 mg of caffeine/day (or up to five 8-ounce cups of caffeinated coffee per day).

For some people, moderate coffee consumption may also be associated with a lower risk of cardiovascular disease. The picture changes at higher doses. Concentrated sources of caffeine, especially energy drinks including energy shots, may raise the risk of cardiovascular problems.

The findings were published in the American Heart Association's flagship peer-reviewed journal Circulation in the scientific statement "Caffeine and Cardiovascular Disease." "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 Chair of the scientific statement volunteer writing group Gregory M. Marcus, M.D., M.A.S., FAHA, a professor of medicine at the University of California, San Francisco School of Medicine and the associate chief of Cardiology for Research at the University of California, San Francisco Health. "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." Why Caffeine Research Is Complicated Understanding exactly how caffeine affects the cardiovascular system is difficult.

Coffee is the main source of caffeine in most studies, but coffee contains many other substances that could influence health. Experimental research suggests that some bioactive compounds in coffee have antioxidant and anti-inflammatory properties, which may contribute to its possible benefits. It is also hard to distinguish the effects of caffeine from those of ingredients commonly added to coffee, including milk, cream, flavored syrups and/or sugar.

Most caffeine research is observational as well, which means it can identify associations but cannot establish cause and effect. Coffee is not the only source of caffeine. Tea, chocolate, soda and energy drinks, as well as over-the-counter and prescription medications, can all add to a person's daily intake.