Sleep Interruptions More Harmful Than Lack of Sleep
Not getting enough sleep is a common grouse. And lack of sleep can not only leave you grumpy and tired but affect memory, concentration and social interactions. It can make you short tempered and even lead to serious health issues.
New research shows that disrupted sleep can affect your mood and behaviour even more than getting the same shortened amount of sleep uninterrupted.
Waking up several times during the night makes you far more grumpy and depressed than not getting enough sleep, with fitful sleep making people less energetic, unfriendly and depressed the next day than people who slept late, reported researchers in the journal Sleep.
Sleep disruptions shorten the periods of deep, slow-wave restorative sleep needed for the brain to feel calm and rested, the study found.
“When your sleep is disrupted throughout the night, you don’t have the opportunity to progress through the sleep stages to get the amount of slow-wave sleep that is key to the feeling of restoration,” says study lead author Patrick Finan, Ph.D., an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.
Building block of cell growth
Sleepless nights short-circuit a fundamental cellular process that drives physical growth, physiological adaptation and brain activity. A study, published in the journal, Plant Cell last month, found that protein synthesis – needed for cell renewal and growth — activity not only changed throughout the day, but also did so under the influence of circadian rhythms, the body’s internal sleep-wake cycle that tells you when to sleep and when to get up.
Since muscle action, brain activity, growth and development are controlled by proteins whose synthesis is carefully regulated – for example, infection reduces protein synthesis activity, making you feel sluggish and tired – insomnia-induced changes in synthesis affect the way we function and develop. This makes sleep even more critical for young children and teenagers, who undergo rapid spurts in growth and development.
A solid night’s sleep
Few, however, are getting enough sleep. Genetic changes in adolescence shift circadian rhythms to almost three hours later during teenage years, leading to chronic sleep deprivation among young people. Teenagers need about nine hours of sleep each day but average around seven hours, largely because they have to get up in time for school irrespective of when they went to bed. Since circadian rhythms determine when the brain and body are at peak functioning, being forced to follow adult-timetables affects the ability to learn, development and health of young people.
Lack of sleep also leads to weight gain, with several studies showing that those who sleep less than seven hours weighed more than those who slept for nine hours or more.
Sleep on it
Truncated sleep raises blood pressure, increases stress hormone levels and causes inflammation, all factors that raise heart disease risk. Chronic sleep deprivation also warps metabolism, causing glucose intolerance and type-2 diabetes. It also causes weight gain by altering metabolic functions, such as how the body processes and stores carbohydrates, and by stimulating the release cortisol, the stress hormone linked to higher amounts of abdominal fat.
The amount of sleep needed varies widely with people, with some making do with six hours a night and others needing up to nine hours. Ideally, adults should target for seven to eight hours of sleep each night, and teenagers go for eight to nine hours. While you don’t need to worry about a sleepless night or two, restless nights for more than two weeks need investigation at a sleep clinic.