For many people, the day does not officially begin until they have had their first cup of coffee. Whether sipped slowly while reading the morning news or grabbed hastily on the way to work, coffee is a daily ritual that fuels millions worldwide. But beyond its ability to provide a much-needed energy boost, new research suggests that drinking coffee at a specific time of day may also have significant health benefits.
A recent study has found that drinking coffee in the morning may lower the risk of death from cardiovascular disease and other causes, whereas consuming coffee throughout the day does not seem to offer the same advantages.
The research, led by Lu Qi, MD, PhD, a professor at the Celia Scott Weatherhead School of Public Health and Tropical Medicine at Tulane University, provides a new perspective on the relationship between coffee consumption and longevity.
Morning Coffee vs. All-Day Coffee: A Surprising Health Advantage
The study revealed that individuals who drank coffee in the morning were 31% less likely to die from heart disease and 16% less likely to die prematurely from any cause compared to those who did not drink coffee at all.
However, people who consumed coffee throughout the day did not experience the same benefits. Their risk of cardiovascular-related death and early mortality was found to be comparable to that of non-coffee drinkers.
This groundbreaking research is the first of its kind to analyze not only the quantity of coffee people consume but also the specific time of day they drink it.
“Our findings indicate that it’s not just whether you drink coffee or how much you drink, but the time of day when you drink coffee that’s important. We don’t typically give advice about timing in our dietary guidance, but perhaps we should be thinking about this in the future,” says Dr. Qi.
How Much Coffee Is Beneficial?
Previous studies have indicated that moderate coffee consumption—approximately 200 to 300 milligrams of caffeine per day (equivalent to two to three 12-ounce cups of coffee)—is linked to a lower risk of heart attack, stroke, and type 2 diabetes. The recent study aimed to build on these findings by investigating whether the timing of coffee intake further influences these health outcomes.
The study, which analyzed data from over 40,000 adults enrolled in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2018, asked participants about their food and beverage consumption, including their coffee habits. Participants reported whether they drank coffee, how much they consumed, and the time of day they typically drank it.
Researchers also examined a subgroup of about 1,400 individuals who completed detailed food and drink diaries over the course of a week. By linking this data with mortality records over a 10-year period, researchers were able to assess the long-term effects of coffee consumption on health.
The study classified morning coffee consumption as occurring between 4 a.m. and 11:59 a.m. Among the participants, approximately 36% drank coffee in the morning, 16% consumed coffee throughout the day, and 48% did not drink coffee at all.
Interestingly, both moderate (two to three cups per day) and heavy morning coffee drinkers (more than three cups per day) experienced significant health benefits, whereas individuals who drank only one cup or less in the morning saw a smaller reduction in risk.
Expert Reactions to the Study
The study has received praise from experts in cardiology and public health, who have long been interested in the relationship between coffee and heart health.
“This is a well-done and fascinating study,” says David Kao, MD, an associate professor of cardiology at the University of Colorado Anschutz Medical Campus, who was not involved in the research. Dr. Kao’s own work has explored the health effects of coffee consumption.
“Many of us who have published in this area have noted that robust observational/real-world studies are needed to answer questions like ‘why’ and ‘how’ this association works, and this is probably the best such next-generation paper I have seen,” he says.
The fact that the greatest health benefits were observed among morning coffee drinkers aligns with previous research on the optimal daily intake of coffee.
“It’s reassuring that several patterns observed previously—such as an apparent ‘sweet-spot’ around two to three cups of coffee per day—suggest that these findings probably are relevant to prior studies. Validation in large independent cohorts really strengthens the arguments,” says Dr. Kao.
Why Might Morning Coffee Be More Beneficial?
Since the study is observational, it does not provide a definitive explanation for why drinking coffee in the morning is linked to reduced mortality, while consuming it throughout the day is not. However, researchers have proposed a few possible reasons.
“A possible explanation is that consuming coffee in the afternoon or evening may disrupt circadian rhythms and levels of hormones such as melatonin. This, in turn, leads to changes in cardiovascular risk factors such as inflammation and blood pressure,” says Dr. Qi.
Nishant Shah, MD, an assistant professor of medicine at Duke University School of Medicine, echoes this idea, noting that the body’s sleep-wake cycle, or circadian rhythm, plays a crucial role in overall health.
“It is well known that good sleep hygiene leads to better health. The authors also nicely note that coffee does contain some anti-inflammatory properties that work best in the morning times [rather than at] later times,” says Dr. Shah.
However, Shah cautions that because this is an observational study, it cannot establish a direct causal relationship between morning coffee consumption and reduced health risks.
“There may also be other factors that influenced the results of the study. For example, early morning coffee drinkers may have better overall health and lifestyle habits than those who drink coffee throughout the day,” he says.
Additionally, because the study relies on self-reported data, recall bias could have influenced the results. Despite these limitations, Shah acknowledges that the researchers took extensive measures to minimize external factors that could have skewed their findings.
Should Afternoon Coffee Drinkers Change Their Habits?
Despite the intriguing findings, experts caution against making drastic changes to coffee consumption habits based solely on this study. There is not yet enough evidence to definitively recommend that individuals limit their coffee intake to the morning hours.
“It’s also worth noting that all-day drinkers don’t have a worse risk compared with non–coffee drinkers, just not a significantly reduced risk,” says Dr. Kao.
This means that while drinking coffee throughout the day may not provide the same heart-health benefits as morning coffee, it is not necessarily harmful either.
“This would suggest that if coffee throughout the day is an important part of someone’s life, and it isn’t causing any harm, there’s no reason to recommend against it,” Dr. Kao adds.
Dr. Qi agrees, emphasizing the need for further research before making firm recommendations.
“More studies are needed to validate our findings in different populations before making recommendations,” he says.
Final Thoughts: Timing May Matter More Than We Thought
The study’s findings open the door for new discussions on the role of coffee in cardiovascular health. While previous research has focused primarily on how much coffee people consume, this study suggests that when they drink it may also play a role.
Morning coffee drinkers appear to have a significant advantage in reducing their risk of heart disease and early death, while all-day coffee drinkers do not experience the same protective effects. The potential connection between coffee, circadian rhythms, and inflammation provides an interesting avenue for future research.
For now, coffee lovers can take comfort in the fact that their morning cup of joe is not just an energy booster—it may also be a heart-healthy habit. And while afternoon coffee may not offer the same benefits, it remains a personal choice that, for many, is still a cherished part of their daily routine.