New research published in the journal Scientific Reports suggests that sleep consistency is more important than pulling all-nighters to cram when it comes to earning a better grades in school.
For their study, researchers had 61 students at Harvard keep an online diary of their sleep schedule for 30 days. Based on this data, students were either placed in the regular sleepers group or the irregular sleepers group. Students were also given a sleep score on a scale from 0-100, with 0 being a completely irregular sleep pattern and 100 being always going to bed and waking up at the same time and achieving a healthy amount of sleep. Researchers found that for every score increase of 10 on the regularity index, the student had an average increase of 0.10 in their GPA.
Delayed Melatonin Release and Circadian Rhythm
Andrew Phillips, lead author of the study and associate professor of medicine at Harvard Medical School, said the findings also revealed that irregular sleepers have a delayed release of the sleep hormone melatonin.
“Our body contains a circadian clock, which helps to keep time for many biological functions,” he said. “One of the key markers of the circadian clock is melatonin. Usually, at nighttime, our circadian clock sends a signal that tells us to release melatonin overnight.”
Irregular sleepers had much later circadian rhythms, by about three hours on average. Dr. Charles Czeisler, study author and chief of the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital in Boston, said that delayed circadian rhythm can leave you feeling jet-lagged.
“That means that if the student had an 8 a.m. class, it would actually be happening at 5 a.m. biological time. It’s as if they were traveling from the East Coast time zone to the Pacific time zone,” Czeisler said. “When circadian rhythms are disrupted, it degrades many different physiological systems in the body and makes individuals much more vulnerable to adverse health outcomes. That could be everything from catching a cold to gaining weight to diabetes, and here in this study, we’re showing it can degrade academic performance as well.”
Kristen Knutson, an associate professor of sleep medicine at Northwestern University and expert in sleep patterns and their relation to health, said sleep regularity is an underrated aspect of overall health.
“Much attention has been paid to sleep quantity and quality, which are important as well,” said Knutson, who was not involved in the new research. “But the importance of sleep doesn’t end there. So, other factors like sleep timing and like sleep regularity are important to provide a more holistic perspective that includes all these dimensions of sleep health.”
Knutson concluded that although it’s not certain that sleep regularity led to a decline in grades, it certainly seems the two behaviors are linked.
“It’s possible that students who have bad sleep habits also have other bad habits that are the reasons behind their poor grades,” Knutson said. “That being said, if it is possible that irregular sleep could impair a student’s ability to do well in school, we really need to understand this further.”
Is your college or grade school kid getting enough quality sleep? Show them this study, and hopefully they’ll make getting more sleep a priority!