Your Nighttime Coffee Habit Might Be Making You More Impulsive

Fly in the Ointment: Whether it’s noon or 3 pm, most of us have a coffee cutoff because we know it affects our sleep. However, a new study suggests that drinking caffeine too late might influence something else: our decision making. 

The Study: Researchers gave fruit flies caffeine under different conditions, comparing daytime versus nighttime exposure and tracking how impulsively the flies behaved afterward. Flies that had caffeine at night had a much harder time stopping themselves from flying into strong airflow, which is basically the fruit fly equivalent of sending a reckless text. Flies that got caffeine during the day showed none of the same behavior. Interestingly, female flies responded more strongly to the stimulus than males. 

The Takeaway: A nighttime cup of coffee may impact your decision-making in addition to your sleep. These findings may have broader implications for people who need to stay alert at night, particularly shift workers. 

Keep in Mind: The researchers say these effects could be especially relevant for women. However, the study was conducted on fruit flies, not humans, so the result might not be totally applicable.