A combined study by researchers in the United Kingdom (University of Oxford) and the United States (Harvard Medical School and University of Nevada) has concluded that the current early start times for schools and universities is detrimental to the kids’ learning and health. To arrive at this conclusion, the team analyzed important research data from the past 30 years correlating sleep medicine and circadian neuroscience.

The National Institutes of Health (NIH), USA, recommends about 7-8 hours of sleep for adults, 9-10 hours for teens, and at least 10 hours of sleep for younger school-aged children. A good night’s sleep is when the body repairs and rejuvenates itself.

However, the Centers for Disease Control and Prevention (CDC) states that sleep deprivation is a public health problem.

Lack of sleep is known to:

• Contribute to metabolicdisorders such as diabetes
• Contribute to cancer
• Cause damage to neurons, indicating that chronic lack of sleep could cause injury to the brain  
• At the gene level, insufficient sleep for one week is reported to alter gene expression, which could have profound impact on the health of an individual.
• Impair memory, since consolidation of newly acquired information in memory happens during sleep

Our bodies operate on a Circadian rhythm in which physical and biological changes follow a 24-hour cycle. The suprachiasmatic nuclei (SCN) of the hypothalamus region in the brain, adapted to the light-dark cycle through specialized photoreceptors in the eyes, coordinates the circadian rhythm, as well as metabolism, sleep, hormones, core body temperature, etc. The sleep-wake cycle is a balance between alertness and a pressure to sleep.

During adolescence, it is reported that the pressure to sleep takes longer to build, extending the waking hours. This shift strikes a discordant note in their Circadian rhythms, causing chronic sleep loss, which reflects in the teens’ behavior. Noticeable changes include:

• Irritability
• Lack of concentration
• Under-performance
• Lack of communication
• Lack of alertness
• Decreased motor performance
• Decreased cognitive performance
• Unintended sleeping
• Increased risk taking
• Mood swings
• Depression

In the article being discussed here, the authors quote several studies to show lack of concentration and reduced alertness in teens with impaired sleep and how sleeping even an extra hour helped. Here are a few examples:

• Adolescent drivers have a peak rate of accident in the mornings, which is attributed to a functional impact of an out-of sync Circadian rhythm.
• When school starting was pushed back by an hour, the rate of accidents involving 17-18 year-olds in a Kentucky school went down by 16.5%, while the state accident rates increased by 7.8%. Students reported sleeping the extra hour in the morning.
• Similar results were obtained in two school districts in Virginia, with the later starting school showing better results.
• When students took the same test at 10.00am and then at 2.00pm, their test scores were significantly better at 2.00pm.
• Moving the start time of school by even one hour improved attendance, achievement, behavior, and mood of the students.

Based on careful review of studies conducted over a 30-year period, the authors opine, “An overview of the circadian timing system in adolescence leading to changes in sleep patterns is given and underpins the conclusion that altering education times can both improve learning and reduce health risks.”

Borrowing the words of Arne Duncan (US Secretary of State for Education), the study concludes, ‘Let teens sleep, start school later.’

Written by Mangala Sarkar, PhD