Study Reveals Drinking coffee increased impulsive behavior in fruit flies, with stronger effects in females and potential implications for night-shift workers.
Drinking coffee late at night to stay awake, new research suggests that habit may have unexpected effects. Scientists at the University of Texas at El Paso report that consuming caffeine at night may increase impulsive behavior, which could encourage riskier actions.
The research investigated how caffeine consumed at night influences inhibition and impulsivity in fruit flies. The study was led by Erick Saldes, Ph.D., Paul Sabandal, Ph.D., and Kyung-An Han, Ph.D. According to Han, the fruit fly species used in the experiments, Drosophila melanogaster, is widely used in behavioral research because its genetic and neural systems share important similarities with those of humans.
“Caffeine is the most widely consumed psychoactive substance in the world, with about 85% of adults in the U.S. using it regularly,” said Sabandal, research assistant professor in UTEP’s Department of Biological Sciences. “Given caffeine’s popularity, we wanted to explore whether additional factors influence its impact on behavioral control.”
Experiments Show Night vs. Day Differences in Fly Behavior
To examine the effects of caffeine more closely, the researchers carried out multiple experiments in which fruit flies were given caffeine in their diets under different circumstances. These conditions included varying caffeine concentrations, consumption during the day or at night, and combinations with sleep deprivation. The scientists measured impulsivity by observing whether the flies could stop moving when exposed to strong airflow, which is naturally unpleasant for them.
