A new study published in the European Heart Journal has found that people who drink coffee primarily in the morning may have a lower risk of death—especially from heart disease—compared to those who drink coffee throughout the day or not at all. The findings suggest that not just how much coffee you drink, but when you drink it, could influence long-term health outcomes.
While previous studies have shown that moderate coffee consumption is generally linked to health benefits, including lower risks of cardiovascular disease and death, results have been mixed—particularly for people who drink large amounts of coffee. Scientists suspected that differences in drinking habits, such as the time of day people consume coffee, might explain some of the inconsistencies in earlier findings.
“Coffee drinking may affect circadian rhythm related behaviors such as sleeping and hormones such as melatonin and cortisol, which are relevant to health. Therefore, the time of coffee drinking may impact health,” said Lu Qi, interim chair of the Department of Epidemiology at Tulane University and HCA Regents Distinguished Chair and Professor.
To investigate this idea, the researchers analyzed data from the National Health and Nutrition Examination Survey, a large, ongoing study of health and diet in the United States. They examined data from over 40,000 adults collected between 1999 and 2018. Participants were asked to recall everything they ate and drank over a 24-hour period, including what time they consumed coffee. The researchers then used a statistical method called cluster analysis to identify common patterns in coffee drinking habits. Two clear groups emerged: those who primarily drank coffee in the morning (between 4 a.m. and noon) and those who spread their coffee consumption throughout the day. A third group included people who didn’t drink coffee at all.
To confirm these patterns, the team analyzed data from two additional studies that tracked dietary habits in over 1,400 health professionals, using more detailed food records collected over seven days. These external studies showed similar trends in coffee drinking times, helping to strengthen the reliability of the results.
After sorting participants into the different coffee-drinking patterns, the researchers tracked health outcomes over nearly a decade. During this time, more than 4,200 participants died. Of those deaths, about 1,270 were from cardiovascular disease, and about 930 were from cancer. The researchers examined whether different coffee drinking patterns were linked to different risks of death, taking into account other factors that might influence health, such as age, race, smoking status, diet quality, physical activity, sleep habits, and total coffee intake.
They found that people who drank coffee mainly in the morning had a significantly lower risk of death from any cause compared to those who didn’t drink coffee at all. Specifically, morning coffee drinkers were 16 percent less likely to die during the study period. The reduction in risk was even greater for deaths related to heart disease: morning coffee drinkers were 31 percent less likely to die from cardiovascular causes than non-coffee drinkers. In contrast, people who drank coffee throughout the day did not have a statistically significant reduction in risk compared to non-coffee drinkers.
Importantly, the study also found that the benefits of drinking more coffee were limited to the morning coffee drinkers. Among those who drank most of their coffee in the morning, higher amounts of coffee were linked to progressively lower risks of death. But for people who drank coffee throughout the day, the amount of coffee they consumed had no clear relationship with risk. This suggests that drinking more coffee isn’t necessarily helpful unless it’s consumed earlier in the day.
These patterns remained even after the researchers accounted for other possible influences, such as short sleep, trouble sleeping, or the consumption of tea and caffeinated soda. The consistency of the findings across different levels of coffee intake and across various groups of people—by age, income, and health status—further supports the link between coffee timing and health.
The findings suggest that “drinking coffee in the morning may benefit health more than drinking in afternoon and evening/night,” Qi told PsyPost.
While the exact reasons for these findings aren’t fully understood, the researchers offered some possible explanations. One involves the body’s natural sleep-wake cycle, known as the circadian rhythm. Drinking coffee in the afternoon or evening may interfere with this rhythm by reducing melatonin production, a hormone that helps regulate sleep and nighttime bodily functions. Disrupted circadian rhythms have been associated with higher blood pressure, inflammation, and increased risk of heart disease.
Another possible explanation has to do with inflammation. Coffee contains compounds that may reduce inflammation in the body, and some inflammatory markers naturally peak in the morning. Consuming coffee during this time might have a stronger impact on lowering inflammation than drinking it later in the day.
Despite the strengths of the study, the researchers acknowledged several limitations. The study was observational, which means it cannot prove cause and effect—only associations. Coffee intake and timing were self-reported, which may introduce errors or inaccuracies in the data. It’s also possible that people who drink coffee only in the morning may differ from all-day drinkers in other ways, such as having healthier routines or sleep habits that weren’t fully captured in the analysis.
“The study is observational in nature, and could not inform causality,” Qi noted.
Even with these limitations, the study opens a new line of inquiry into how the timing of food and beverage consumption could influence long-term health. Future research may explore how coffee timing interacts with shift work, genetic differences in caffeine metabolism, or other lifestyle factors. For now, the findings suggest that enjoying your coffee in the morning—not just how much you drink—could be an important part of a healthier routine.
Looking forward, Qi hopes to “test the causal effects of coffee drinking time on human health in clinical trials.”
The study, “Coffee drinking timing and mortality in US adults,” was authored by Xuan Wang, Hao Ma, Qi Sun, Jun Li, Yoriko Heianza, Rob M Van Dam, Frank B Hu, Eric Rimm, JoAnn E Manson, and Lu Qi.
