A morning cup of joe appears to be good for the heart, but it might be time to reconsider the afternoon coffee run.
People who only drank coffee in the morning were less likely to die of heart problems compared to non-coffee drinkers, according to a new study published in the European Heart Journal. But those health outcomes were not observed among people who drank coffee throughout the day.
Researchers analyzed data from more than 40,000 U.S. adults who reported whether they drank coffee, how often, and when. The team found two distinct patterns among coffee drinkers – those who just drank coffee before midday, and another smaller group who drank coffee throughout the day.
By linking the people to public death records over a period of 10 years, the study showed that morning coffee drinkers had a 16% lower risk of death from any cause and a 31% lower risk of death from cardiovascular problems than non-coffee drinkers. There was no difference in risk of death between daylong coffee drinkers and non-coffee drinkers.
“This is the first study testing coffee drinking timing patterns and health outcomes. 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,” said researcher Lu Qi, MD, PhD, director of the Tulane University Obesity Research Center, in a news release.
“This study doesn’t tell us why drinking coffee in the morning reduces the risk of death from cardiovascular disease,” Qi continued. “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.”
The benefits of morning coffee were observed among people who reported drinking any amount before noon, but the greatest benefits were seen among those who said they drank at least two cups.
These latest findings may be related to how coffee impacts the sympathetic nervous system, which prepares the body for action, an expert not involved in the research suggested.
“Why would time of the day matter? In the morning hours there is commonly a marked increase in sympathetic activity as we wake up and get out of bed, an effect that fades away during the day and reaches its lowest level during sleep,” wrote Thomas F. Lüscher, MD, a cardiologist at Royal Brompton and Harefield hospitals in London, as part of an accompanying editorial. “Thus, it is possible, as the authors point out, that coffee drinking in the afternoon or evening disrupts the circadian rhythm of sympathetic activity. Indeed, many all-day drinkers suffer from sleep disturbances. In this context, it is of interest that coffee seems to suppress melatonin, an important sleep-inducing mediator in the brain.”
Other possible health impacts of coffee may be that it can blunt the effects of mental stress and also possibly reduce inflammation, Lüscher noted.
“Overall, we must accept the now substantial evidence that coffee drinking, particularly in the morning hours, is likely to be healthy,” Luscher concluded. “Thus, drink your coffee, but do so in the morning.” (https://www.webmd.com/diet/news/20250108/coffee-benefits-limited-morning-hours)
