Sleep Patterns Have Health Consequences
Should night owls try to adopt an earlier sleep pattern?
More than a third of American adults routinely fail to get the seven or more hours of nightly sleep that’s generally recommended for optimal health, the Centers for Disease Control and Prevention said last year. In some cases, biology may be to blame. Some say there is an environmental component involved, so night owls with no job flexibility should try to adopt an earlier sleep pattern. Others say trying to override your natural tendencies is extremely difficult and could do more harm than good. Nathaniel F. Watson, a professor of neurology at the University of Washington in Seattle, says some night owls would benefit by trying to change their sleep patterns. Katherine Sharkey, an associate professor of medicine at Brown University’s Alpert Medical School, says going against your natural tendencies can sometimes do more harm than good and one must individualize the approach.
Everyone has an internal clock, or circadian rhythm, that regulates feelings of sleepiness and wakefulness over a 24-hour cycle. These patterns vary from person to person, however, which is why some people function best in the morning and others seem to have more energy late at night.
Those who fall into the “night owl” category—almost 20% of Americans, by some estimates—have a problem in that their internal clocks are out of sync with society’s external ones, which generally favor early start times for school and work. From a health standpoint, the ideal time to sleep is during the “biological night,” or when all of a person’s clocks are coordinated and fulfilling their usual nighttime activities. For night owls, this “sweet spot” for sleep occurs at a later time than for early birds. Numerous studies have demonstrated that desynchronized rhythms are associated with negative health consequences, including disrupted and shortened sleep, problems with mood regulation, metabolic abnormalities that increase risk of obesity and diabetes, cognitive dysfunction and even increased cancer risk.
The well-known proverb “Early to bed and early to rise makes a man healthy, wealthy and wise” appeared in Benjamin Franklin’s annual almanac in the mid-1700s, a time when bloodletting was commonplace in medical practice and the discovery of penicillin was nearly two centuries away. Yet this quip provides insight that, nearly 300 years hence, is germane to our discussion of health and human circadian rhythms, which are biological processes, such as the sleep-wake cycle, that persist in approximately 24-hour periods. Their fluctuations can be synchronized to the 24-hour day by environmental stimuli such as light. Bright light exposure through light boxes and outdoor light can help resynchronize misaligned clocks for some individuals.
We are beginning to understand that being an evening type is bad for your health. Evening types have poorer diets, reduced quality of life and more depression, and they consume more alcohol than morning types. They also take longer to fall asleep and, perhaps most important, they sleep less.
The harsh reality is that modern society is hard on evening types. The 8 a.m. workday requires an early wake time, which, in turn, requires an early bedtime to allow for the seven or more hours of nightly sleep that is generally necessary for optimal health. Evening types don’t go to bed early; it isn’t in their nature. The end result is that evening types often end up chronically sleep-deprived, which is perilous to their health.
Clearly, we should strive to avoid these complications by prioritizing sleep in our lives, but simply ambling off to bed earlier isn’t an easy solution for evening types. The most practical solution for evening types is to pursue careers with flexible hours. Evening types are only systematically sleep-deprived to the extent that they have an externally imposed early wake time. Left alone, evening types can have a happy and healthy “sleep life” with adequate nightly duration by just going to bed when tired and waking when rested, regardless of the time of day, if they can control external influences.
But for the majority of evening types who lack this flexibility, it is worth making changes to foster an earlier bedtime.
Light is by far the most important factor that helps entrain, or synchronize, human circadian rhythms. To push to an earlier bedtime, evening types should get morning exposure to bright light, from ambient light or a therapeutic light box. Avoiding light in the evening is crucial for those seeking an earlier bedtime. This means that TVs, smartphones, tablets and laptops must be put away at an earlier hour.
Morning exercise is helpful, as is a regular bedtime routine that signals to the body that sleep is imminent. Bedtimes and wake times must be consistent: Taking melatonin a few hours before the intended bedtime also can help some people, but it shouldn’t be necessary long-term.
The reality is, people who try to change their natural sleep patterns often end up getting less sleep or poor-quality sleep. Many night-shift workers, for example, live with chronic circadian desynchrony because their bodies never fully adapt to working at night and sleeping during the day.
So, what is a 24-hour society to do to minimize the health risks of circadian desynchrony?
Solutions include the adoption of flexible schedules that allow people to work during their individual circadian daytime if possible. More research on countermeasures like melatonin and light is needed to determine best practices and whether such interventions are safe. Finally, increasing education about circadian rhythms and sleep will help individuals keep track of how their sleep patterns affect their health. Initiating “Sleep Hygiene” techniques have shown beneficial outcomes.
Sleep hygiene — Sleep hygiene refers to actions that tend to improve and maintain good sleep:
● Sleep as long as necessary to feel rested (usually seven to eight hours for adults) and then get out of bed
● Maintain a regular sleep schedule, particularly a regular wake-up time in the morning
● Try not to force sleep. Do not go to bed until sleepy and use the bed primarily for sleep (and not for reading, watching television, eating, or worrying). Do not spend more than 20 minutes in bed awake. If awake after 20 minutes, leave the bedroom and engage in a relaxing activity, such as reading or listening to soothing music.
● Avoid caffeinated beverages after lunch
● Avoid alcohol near bedtime (eg, late afternoon and evening) Avoid smoking or other nicotine intake, particularly during the evening
● Adjust the bedroom environment as needed to decrease stimuli (eg, reduce ambient light, turn off the television or radio)
● Avoid prolonged use of light-emitting screens (laptops, tablets, smartphones, ebooks) before bedtime
● Resolve concerns or worries before bedtime. Once asleep if awakened, do not “Process” ideas. Make a deliberate effort to keep the mind focused on relaxed, pleasant thoughts.
● Exercise regularly for at least 20- 30 minutes, preferably more than four to five hours prior to bedtime
● Avoid daytime naps, especially if they are longer than 20 to 30 minutes or occur late in the day
Advancing bedtimes for evening types isn’t easy, but for most it is necessary to reap the benefits of adequate, regular sleep duration, which is a prerequisite to a healthy life. For evening types pursing this goal, the wisdom of Benjamin Franklin again provides insight, in that “energy and persistence conquer all things.”
Paul R. Block, MD, FACP, FCCP
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