Diligently staying up long into the night to finish a project or waking up ridiculously early to catch an airplane may be necessary, or at least seem necessary. But there are many reasons why we feel and look so haggard when we go without sleep—or disrupt our normal patterns. As we age, our circadian rhythms become less regulated in general, so quality sleep becomes more important and the costs of sleep disruption get higher. So it’s worth understanding what we trade away when we choose not to sleep—and why we suffer so much when we suffer from insomnia.
When we sleep our bodies eliminate most of the neurotoxins and other metabolic wastes that build up in our brains when we’re awake, explains MIT neuroscience associate professor Dr. Edward Boyden. During sleep, the glymphatic system increases the flow of cerebrospinal fluid in the spaces between our brain cells, thereby flushing out these harmful molecules. Preliminary studies show that the cerebrospinal fluid barely moves from our brains when we’re awake. If not flushed out, these toxins can cause neurodegeneration.
Even if the total hours we sleep are optimal, disrupted sleep is still linked with neurodegeneration, depression, impaired immune function, and impaired glucose metabolism, which leads in turn to obesity and type 2 diabetes. Studies on mice show that chronic disrupted sleep leads to cell death in the hypothalamus and other areas that help keep us alert and awake. The damage seems to be long term—a month after the end of the study the mice had trouble staying awake during their active hours.
When we sleep matters too. Further studies show that if we don’t sleep in sync with our circadian rhythm, our REM phase of sleep and other important sleep processes become inefficient, which has been shown to lead to inefficient memory consolidation.
Sleep disruption has been shown to disturb the internal clocks that regulate our genes. During optimal sleep—at night, when the temperature is low and melatonin is high—6.4 percent of our blood cells’ RNA is rhythmic. In contrast, if we delay our sleeping time for four hours or more, only 1 percent of that RNA is rhythmic. Thus, sleeping during nonoptimal hours can cause an 84 percent decrease in gene transcription.
If we go one week with poor sleep, there is an added 20 percent decrease in our whole body’s gene expression. Some of the genes affected are involved in inflammation, stress control, appetite control, and immune responses, which could explain why sleep deprivation is so debilitating.
Poor sleep also deregulates the processing of reward and loss information, leading to increased risk taking and thrill seeking, as well as reduced optimism, sociability, emotional intelligence, emotional control, and constructive thinking. Thus, chronic poor sleep can lead to a severe impairment of our understanding of our daily accomplishments and failures, which can lead to misjudging ourselves and others.
When we don’t sleep well, we tend to get fat, fall apart, and lose touch with who we are. It’s a sad fact that daily life has become so stressful in industrialized societies that mistimed sleep, sleep disturbances, insufficient sleep, and insomnia are chronic. In fact, studies at Harvard have found that one in five Americans gets less than six hours of sleep per night. Not coincidentally, there has been a simultaneous increase in diabetes, obesity, and depression.
The solution is of course to protect our sleep as best we can. Keep off the red-eye and the early flights; exercise regularly; maintain a steady sleep schedule; fast during the night; get rid of noise and light; turn off your cell phone and other distractions; and sleep naked to keep your skin temperature cool and your melatonin high. The good news is that the symptoms of lack of sleep tend to disappear quickly once quality sleep returns.
Better Than Pills
Meditating As a Substitute for Sleep
While sleeping pills have gotten better in recent years, sleep has turned out to be more complex than anyone knew. So popping pills to get to sleep remains a suboptimal solution at best—and may prove to be a seriously bad idea. Likely better—and certainly safer—is to develop a meditation practice. Research suggests that we can replace a significant amount of sleep with meditation.
One study of long-term meditators—who’ve been consistently meditating for an average of 2.3 hours per day for three or more years—found that they only needed to sleep about 5.2 hours per night. These meditators showed no signs of sleep deprivation and performed well on mental performance tests. Buddhists texts state that advanced meditators should only need four hours of sleep, and some advanced meditation practitioners claim to need only 1.5 to three hours of sleep. Meditating for hours at a time can have dramatic effects, reshaping the brain for happiness and optimism. That said, novice meditators will likely feel fatigued and need to sleep longer while their bodies become acclimated to regularly meditating for long periods.