Morning coffee boosts mood better than later in the day, research suggests

A German study has found that regular caffeine drinkers tend to be in a better mood after a cup of coffee or another caffeinated drink — more noticeably in the morning than later in the day.

The researchers note that the mood-boosting benefits were strongest within the first 2.5 hours after waking up, tiredness and social context moderated this association. Participants reported feeling significantly happier and more enthusiastic when they had their morning coffee compared to the same time on other days without the drink.

Moreover, after drinking coffee, participants felt slightly less sad or upset than on comparable days without coffee. Unlike the boost in positive emotions, this effect was not dependent on the time of day.

“Around 80% of adults worldwide consume caffeinated beverages, and the use of such stimulating substances dates far back in human history,” says senior author Sakari Lemola, professor at Bielefeld University.

“Even wild animals consume caffeine; bees and bumblebees prefer nectar from plants that contain caffeine.”

Differences across individuals

For their study published in Scientific Report, the authors at Bielefeld University and the University of Warwick (UK) set out to study caffeine consumption in everyday life, not just in artificial laboratory settings.

The authors analyzed data from 115 German participants aged 18–25 for two weeks, and another group of 121 adults aged 18–29 for 28 days.

Participants completed short questionnaires on their phones seven times a day, indicating their current mood and whether they had consumed a caffeinated drink in the preceding 90 minutes.

In addition, the researchers determined whether coffee prompted different effects across individuals. For example, they anticipated that more anxious participants would experience negative mood changes, such as increased nervousness, after consuming caffeine.

However, co-author Justin Hachenberger from Bielefeld University in Germany, says the links between caffeine intake and positive or negative emotions were fairly consistent across all groups.

“We were somewhat surprised to find no differences between individuals with varying levels of caffeine consumption or differing degrees of depressive symptoms, anxiety, or sleep problems,” says Hachenberger.

He details that people who react to caffeine poorly likely avoid it and that this study did not include people who completely abstain from caffeine.

Boosting energy levels

The researchers associate caffeine’s morning mood-boosting property with its ability to block adenosine receptors, which boosts wakefulness and energy levels.

Co-author Anu Realo, professor at the University of Warwick, says blocking these receptors can increase dopamine activity in key brain regions — “an effect that studies have linked to improved mood and greater alertness.”

At the same time, the researchers note it’s unclear whether these effects are linked to a reduction in withdrawal symptoms after a night’s sleep. “Even people with moderate caffeine consumption can experience mild withdrawal symptoms that disappear with the first cup of coffee or tea in the morning,” says Realo.

The study authors caution that excessive caffeine intake is linked to various health risks, while consuming it later in the day can lead to sleep problems. Moreover, they stress that caffeine can lead to dependence. 

Caffeine hot takes

When consumed in moderation, caffeine’s benefits are elucidated in other recent scientific research. One analysis found caffeine may be effective in helping slow down aging at a cellular level, by tapping into an ancient cellular energy system. The investigation of fission yeast — a single-celled organism “surprisingly similar” to human cells — found that caffeine helps cells sustain life.

A separate paper suggests that a daily cup of caffeinated coffee may lower all-cause mortality risk by 16%. Specifically, black coffee and coffee with low added sugar and saturated fat were associated with a 14% lower risk of mortality.

Meanwhile, in prenatal research, scientists found caffeine may protect babies by preventing dangerous drops in oxygen that can cause death. Sudden Unexpected Infant Death is the leading cause of infant deaths between one and 12 months old.