The Impulsive Impact Of Drinking Coffee At Night, According To Science

Powering through a night shift? Drinking a cup of coffee may be the best way to finish lingering tasks or get through momentary fatigue. Just as science determined that the best time to drink coffee is in the morning, it has also realized that drinking a cup of coffee at night isn't so strange, especially if you need a boost in energy to keep you awake. However, this spurt in stamina may also come with some consequences. A new study has found that a dose of nighttime caffeine may lead to impulsive behavior and cause drinkers to take greater risks.

To better understand how coffee affects the mind and body of nighttime drinkers, researchers at the University of Texas at El Paso examined the influence of caffeine on fruit flies at night. The species they used has genetic and neural systems that are similar to that of humans, and a series of experiments showed the team that the fruit flies behaved erratically due to the nighttime caffeine. 

"Under normal circumstances, flies stop moving when exposed to strong airflow. We found that flies consuming caffeine at night were less able to suppress movement, displaying impulsive behaviors such as reckless flying despite these aversive conditions," said researcher Erick Saldes, Ph.D.(via SciTechDaily).

Coffee has a long history: Its earliest documented use was in 1,000 B.C. in Ethiopia. Given that time frame, and the drink's worldwide popularity, you would think that mankind has already uncovered every side of coffee. Yet, new studies continue to show us that coffee has powers we're only beginning to understand. The new study, which was published in iScience, sheds light on how a nighttime dose of coffee could spell trouble for women who drink coffee. In clinical trials involving fruit fly models, the scientists observed that female fruit flies displayed more impulsive behavior, despite receiving the same dose of caffeine as their male counterparts.

"Flies don't have human hormones like estrogen, suggesting that other genetic or physiological factors are driving the heightened sensitivity in females," said team member and biological sciences professor Kyung-An Han (via SciTechDaily). The researchers indicated that their findings could help explain how drinking coffee at night influences impulsive behavior in people and especially women, but further research is needed for conclusive results. It is worth noting that in a different study that didn't factor in coffee intake, female night shift workers were already found to be at a high risk of workplace injuries and other errors due to the negative effect of sleep loss on the circadian rhythm.