Taking Naps and Eating Food During Shift Work Could Reduce Alertness, Says Research

Health care and social assistance workers have been warned that eating a meal and taking a power nap during shift work could be dangerous, as research shows this may reduce alertness.      

Researchers from the University of South Australia looked at the effect of napping and eating on the functionality of night shift workers, a quarter of whom work in health and social assistance industries.

While many shift workers rely on naps to function, the researchers said long naps could make you feel groggy and sluggish.

Also, performance could be impaired in the hour following a nap, which could be dangerous for health professionals in charge of caring for others.

Even though shorter “power naps” are often touted as a good method to increase alertness, there has been no definitive research to suggest that this works at night.

They recommended shift workers test out if napping is helpful on an individual basis, before proceeding to take naps at work.

Eating was another tool shift workers often used to combat exhaustion, but research has shown there were dangers to eating at night, when the body was meant to be asleep.

Charlotte Gupta is a PhD candidate at the University of South Australia, who has studied the impacts of eating a meal during shift work.

She told Pro Bono News that eating a large meal at night was found to negatively affect alertness and performance.

“Initially we did a small pilot study with 10 people and it was really the first study to look at eating during the night and what that does to performance,” Gupta said.

“So because it was that first step, we wanted to know what the difference was between eating something big and not eating at all. So we had five people eat a really big meal and five people not eat anything at all during the night shift.

“And the people that ate a big meal performed a lot worse on a driving simulator task. They crashed a lot more, had trouble sticking to speed limit and driving straight. But people that didn’t eat at all drove a lot more safely.”

While the study involved a driving simulation, Gupta said the results would have real-world consequences for shift workers in the health and social assistance industries.

“So the driving task obviously relates to driving but there’s also a reaction time component to it. We got them to do a really simple three-minute task, which involves just responding to a stimulus,” Gupta said.

“And people that ate were responding a lot slower [meaning] their basic reaction time was impaired. And when you think of nurses who are responding to patient alarms…that breakdown in not being able to respond as quickly can be very damaging.”

Gupta said sleep deprivation also had an effect on work performance, especially during night shifts.

“Any amount of sleep deprivation has an effect on your reaction time particularly at night, because at night we’re already slower to react than during the day. And if we add sleep deprivation on top of that, then we’re going to be reacting even slower,” she said.

While eating a large meal may impede alertness, Gupta added that eating a snack may be a safe compromise for hungry shift workers.

“We’re now extending our research and looking at a snack as a possible alternative. So giving some people a large meal, some a small snack and some nothing at all and then looking at the differences,” she said.

“And we’re finding that again the big meal is bad, but the small snack seems to be no different to not eating at all. So it is a good alternative for safe [levels of alertness].”

Overall, Gupta said there were a varied number of methods shift workers employed to stay alert during long shifts, with further research needed to find the best solution.

“There’s different things that different people do. A lot of shift writers have a whole bunch of countermeasures that they have in place and some of that does involve eating food,” she said.

“Other than food, caffeine is a huge one. There’s a lot of research currently being done looking at the effects of caffeine, and what that does immediately and then throughout the night. When [combined] with food and napping, we’re not really sure how they all work together.

“So people might have individually good countermeasures, but what that combination is doing is still unknown.”