A new scientific statement from the American Heart Association says that drinking up to five 8-ounce cups of coffee a day is safe for most healthy adults and may even reduce the risk of several serious health conditions, including heart disease, stroke, heart failure and Type 2 diabetes.
Published Monday in the journal *Circulation*, the statement reviewed dozens of studies examining the effects of coffee and caffeine on heart health. Researchers found that consuming about three to five cups of coffee daily — roughly 400 milligrams of caffeine — was consistently associated with the greatest health benefits.
The review helps clarify years of conflicting research that alternately linked coffee to both health risks and benefits. While many of the studies were observational and cannot prove cause and effect, researchers said an increasing number of randomized clinical trials have also pointed to positive effects.
Scientists believe caffeine may benefit the heart in several ways. Studies suggest people tend to be more physically active on days they drink caffeinated coffee, while caffeine may also help lower blood pressure and reduce the risk of atrial fibrillation, an irregular heartbeat that can increase the risk of stroke.
Coffee also contains naturally occurring compounds called polyphenols, which have antioxidant and anti-inflammatory properties. Those compounds may explain why some studies have found health benefits from decaffeinated coffee as well.
Researchers cautioned that individual responses to caffeine vary because of genetics and other factors. While the evidence suggests the “sweet spot” is generally between two and four cups per day, consuming up to five cups appears safe for most adults.
The health benefits can disappear, however, if coffee is loaded with sugar, flavored syrups, or creamers high in saturated fat.
Other caffeinated beverages, particularly energy drinks, are a different story, the report cautioned. Many contain significantly more caffeine than coffee and have been linked to irregular heart rhythms and elevated blood pressure. Researchers recommend limiting or avoiding energy drinks despite the favorable findings for coffee.
Source: American Heart Association