A new scientific study published in the journal Circulation, a publication of the American Heart Association, has revealed that the habit of drinking coffee may be beneficial for cardiovascular health.

Researchers, in collaboration with the American Heart Association, reviewed findings from studies conducted over the past decades and concluded that consuming up to 400 milligrams of caffeine per day—equivalent to about five 8-ounce cups of coffee—is safe for most adults and may provide heart health benefits.

The researchers indicated that consuming up to 400 milligrams of black coffee per day is associated with lower rates of heart disease, heart failure, stroke, and heart rhythm disorders, as well as a reduced risk of type 2 diabetes.

Although the results point to potential benefits of black coffee for heart health in many adults, the researchers emphasized the need for further studies to understand the impact of other caffeine sources, such as tea, on cardiovascular health.

But there is a key condition: these findings apply only to black coffee, not to coffee drinks sweetened with sugar or those with added cream or cream substitutes.

Coffee has health benefits when consumed without added sweeteners or cream; these additions 'likely reduce its health benefits,' according to a press release from the American Heart Association regarding the new study.

The Association generally recommends that adults limit their consumption of whole milk due to its high saturated fat content. Whole milk, along with half-and-half (which it contains), is among the most common additions to coffee.

The study also emphasizes that the method of preparing coffee plays a role in its health benefits.

The compound cafestol, found in coffee brewed with a French press, Turkish coffee, espresso, and boiled coffee, is associated with elevated levels of LDL (bad) cholesterol, which increases the risk of heart attacks and strokes.

In contrast, this is not a concern with instant coffee or coffee prepared using paper filters, as they do not contain cafestol.

No ideal amount for everyone

Some studies have shown that drinking one to three cups of coffee per day was associated with an increased risk of high blood pressure in healthy individuals, but this association was not seen in those who drank more than three cups per day.

Dr. Gregory M. Marcus, chair of the scientific statement writing group and professor of medicine at the University of California, San Francisco School of Medicine, said: 'Although research suggests that caffeine consumption may be associated with some cardiovascular health benefits in some people, it is important to remember that there is no one-size-fits-all recommendation for safe caffeine consumption.'

Marcus explained that factors such as age, health status, genetics, and medications affect how the body processes caffeine, and thus the appropriateness of the amount each person consumes.

Marcus added: 'What might be an appropriate amount for one person may cause undesirable effects in another, such as palpitations, anxiety, or sleep disturbances.'

He noted that most people are aware of their appropriate daily caffeine intake, and if you are considering an extra cup of black coffee, it is likely safe for you.