Cheating Ourselves of Sleep
Think you do just fine on five or six hours of shut-eye? Chances are, you are among the many millions who unwittingly short change themselves on sleep.
Research shows that most people require seven or eight hours of sleep to function optimally. Failing to get enough sleep night after night can compromise your health and may even shorten your life. From infancy to old age, the effects of inadequate sleep can profoundly affect memory, learning, creativity, productivity and emotional stability, as well as your physical health.
A number of bodily systems are negatively affected by inadequate sleep: the heart, lungs and kidneys; appetite, metabolism and weight control; immune function and disease resistance; sensitivity to pain; reaction time; mood; and brain function.
Poor sleep is also a risk factor for depression and substance abuse, especially among people with post-traumatic stress, people with PTSD tend to relive their trauma when they try to sleep, which keeps their brains in a heightened state of alertness.
The elderly are especially vulnerable but many are helped by standard behavioural treatments for insomnia, like maintaining a regular sleep schedule, avoiding late-in-day naps and caffeine, and reducing distractions from light, noise and pets.
It should come as no surprise that myriad bodily systems can be harmed by a chronically shortened night’s sleep which affects almost every tissue in our bodies.
Several studies have linked insufficient sleep to weight gain. Not only do night owls with short changed sleep have more time to eat, drink and snack, but levels of the hormone leptin, which tells the brain enough food has been consumed, are lower in the sleep-deprived while levels of ghrelin, which stimulates appetite, are higher.
In addition, metabolism slows when one’s circadian rhythm and sleep are disrupted; if not counteracted by increased exercise or reduced caloric intake, this slowdown could add up to 10 extra pounds in a year.
The body’s ability to process glucose is also adversely affected, which may ultimately result in Type 2 diabetes. In one study, healthy young men prevented from sleeping more than four hours a night for six nights in a row ended up with insulin and blood sugar levels like those of people deemed prediabetic. The risks of cardiovascular diseases and stroke are higher in people who sleep less than six hours a night. Even a single night of inadequate sleep can cause daylong elevations in blood pressure in people with hypertension. Inadequate sleep is also associated with calcification of coronary arteries and raised levels of inflammatory factors linked to heart disease. (In terms of cardiovascular disease, sleeping too much may also be risky. Higher rates of heart disease have been found among women who sleep more than nine hours nightly.)
The risk of cancer may also be elevated in people who fail to get enough sleep. The increased risk may result from diminished secretion of the sleep hormone melatonin.
Children can also experience hormonal disruptions from inadequate sleep. Growth hormone is released during deep sleep; it not only stimulates growth in children, but also boosts muscle mass and repairs damaged cells and tissues in both children and adults.
Some of the most insidious effects of too little sleep involve mental processes like learning, memory, judgment and problem-solving. During sleep, new learning and memory pathways become encoded in the brain, and adequate sleep is necessary for those pathways to work optimally. People who are well rested are better able to learn a task and more likely to remember what they learned. The cognitive decline that so often accompanies aging may in part result from chronically poor sleep.
With insufficient sleep, thinking slows, it is harder to focus and pay attention, and people are more likely to make poor decisions and take undue risks. As you might guess, these effects can be disastrous when operating a motor vehicle or dangerous machine.
In driving tests, sleep-deprived people perform as if drunk, and no amount of caffeine or cold air can negate the ill effects.
At your next health check-up, tell your doctor how long and how well you sleep. Be honest: Sleep duration and quality can be as important to your health as your blood pressure and cholesterol level.