Coffee is America’s favorite beverage. More than 70% of American adults drink coffee each week, making it the most consumed beverage other than water.

There is clear evidence that coffee is a superfood that helps to prevent diseases, including cancer, heart disease, diabetes, and Parkinson’s disease, and others.

Now a new longitudinal study finds that limiting coffee consumption to the morning may lead to greater health benefits.

The paper, published in the European Heart Journal, analyzed data from three separate studies. One study, the National Health and Nutrition Examination Survey, included reports from 40,000 adults collected between 1999 and 2018 of everything they ate and drank over a 24-hour period, including what time they consumed coffee. Researchers also analyzed data from the other two studies that tracked the dietary habits of more than 1,400 health professionals over the course of seven days.

Researchers classified participants into three groups: those who primarily drank coffee in the morning, those who spread their coffee consumption throughout the day, and those who didn’t drink coffee at all. Then, they tracked health outcomes for participants over the next 10 years to determine whether the timing of coffee consumption impacted their health. Over that period, more than 4,200 of the participants died, including approximately 1,270 from cardiovascular disease and 930 from cancer.

Researchers found that people who drank coffee mainly in the morning had a significantly lower risk of death – they were 16% less likely to die – compared to those who didn’t drink coffee at all. And morning coffee drinkers were 31% less likely to die from cardiovascular causes than non-coffee drinkers. But people who drank coffee all day did not significantly lower their risk of dying compared to non-coffee drinkers. In other words, drinking coffee all day did not provide a benefit.

The data also demonstrated that for those who drank coffee in the morning, increasing their coffee intake lowered their risk of dying. For those who drank their coffee throughout the day, increasing coffee consumption did not reduce the risk of dying. Essentially, drinking more coffee is only beneficial unless you drink it in the morning.

The results used statistical analysis to account for other factors that influence the overall risk of death, including age, race, smoking, nutrition, physical activity, sleep habits and overall health status.

What’s going on here? The link between morning coffee consumption and a lower risk of dying isn’t fully understood. Researchers hypothesize that morning coffee may better support the body’s natural sleep-wake cycle. Caffeine later in the day likely disrupts circadian rhythm, which is linked with higher blood pressure, inflammation and increased risk of heart disease.

Coffee is also known for its anti-inflammatory properties. The body’s natural inflammatory markers naturally peak in the morning, so drinking coffee in the morning may reduce inflammation.

The authors did not indicate that the study is observational, and that coffee intake was self-reported by participants, which can lead to inaccuracies.

The take-home message: Evidence suggests that drinking coffee is good for you, but only if you consume it in the morning!