Does drinking coffee at night make us more impulsive and reckless?

A new study from the University of Texas at El Paso (UTEP) in the US shows that drinking coffee at night can increase impulsive behavior, even leading to reckless actions.

Coffee has long been a favorite beverage for many, especially office workers and night shift workers. However, scientists warn that consuming coffee at night can negatively impact behavioral control.

The study was conducted at the Department of Biology, University of Texas at El Paso (UTEP), USA, and published in the journal iScience. The research team used fruit flies (Drosophila melanogaster), a species commonly used in behavioral research due to its genetic and neurological similarities to humans, to examine the effects of coffee consumption at night.

"Caffeine is the most widely consumed psychoactive substance in the world , with about 85% of adults in the U.S. using it regularly," said researcher Paul Sabandal, a lecturer in the UTEP biology department. "We wanted to find out if there are any factors that cause caffeine to affect behavior differently."

In a series of experiments, researchers fed flies diets containing caffeine at varying doses, differentiating between daytime and nighttime consumption, with or without sleep deprivation.

The results showed that flies given caffeine at night tended to react more impulsively. Specifically, they were less likely to stop moving when encountering strong gusts of wind, a natural irritant, and instead continued to fly erratically.

"Normally, flies stop flying when they encounter strong winds. But when they consume caffeine at night, they fly recklessly, despite the discomfort," researcher Erick Saldes shared.

Conversely, when caffeine is consumed during the day, this unusual behavior does not occur.

Coffee has many benefits, but only when consumed in moderation and at the right time - Photo: AI

Notably, the study also revealed a clear difference between sexes: although the amount of caffeine in their bodies was similar, female flies exhibited more impulsive behavior than male flies.

"Flies don't have hormones like humans, such as estrogen. This suggests there may be other genetic or physiological factors that make their offspring more sensitive to caffeine," Professor Kyung-An Han explained.

Although the study was conducted on fruit flies, experts believe that these results still have many important implications for humans.

Fruit flies (Drosophila melanogaster) are a popular biological model in neuroscience research because they share many similarities with humans in terms of genetic structure and neural responses. Behaviors such as learning, memory, and responses to stimuli can all be studied in this species.

Therefore, the fact that fruit flies exhibit impulsive behavior after consuming caffeine at night suggests the possibility of a similar reaction occurring in humans, particularly in situations of sleep deprivation or night shift work.

While caffeine can help you stay alert, it can impair your ability to control your behavior if used at the wrong time. This is especially important to note for groups such as healthcare workers, long-distance drivers, night shift workers, or anyone who habitually drinks coffee late at night.

This study opens new avenues for better understanding the neurological effects of caffeine and encourages further research on humans.

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MINH HAI

Source: https://tuoitre.vn/uong-ca-phe-ban-dem-khien-ta-boc-dong-lieu-linh-hon-20250806144100889.htm