by Morgan A. McLaughlin McFarland
Sleep is as strong a biological need as food, water and shelter. Without adequate sleep, physical health degrades and mental health suffers. Sleep deprivation wreaks such profound havoc on the mind and body that it's used in some cultures as an enhanced interrogation technique for prisoners. Achieving adequate sleep can be a challenge, however, as variances in work and school schedules, medical conditions like insomnia or lifestyle choices can all interfere with the ability to fall into a deep, restorative sleep. What does the ideal sleep cycle look like and how can we achieve it?
The Clinical Need for Sleep
One cause for sleep difficulties may be your work schedule, particularly shift work that involves late or irregular hours. Inconsistency in bedtime and waking time or attempting to sleep during daylight hours can make achieving an adequate amount of sleep difficult.
"Humans are best suited to sleeping when it is dark outside. We release melatonin when it gets dark and when our bodies are cooling down," says Nancy Collop, MD, director of the Emory Sleep Center and professor of Medicine and Neurology at the Emory University School of Medicine. The National Sleep Foundation suggests a melatonin supplement can replicate the body's natural melatonin production in certain cases, such as jet lag and shift work, by resetting the body's internal clock. Melatonin supplements are not a substitute for the proper amount of sleep, however, and have not been adequately studied for use in treating sleep disorders.
Taz Bhatia, MD, of CentreSpringMD stresses the importance a consistent sleep schedule. "Most people sleep an average of seven hours per night, falling asleep and waking up at the same times," says Bhatia. "Professions that demand otherwise accelerate aging and disease."
When should those seven hours of sleep fall? While sleep time may vary, most people's ideal sleep schedule falls within a specific window of time.
"Most people go to sleep between around 10 p.m. to 12 a.m. and rise around 6 a.m. to 8 a.m.," says Hitendra Patel, MD, Medical Director of the WellStar Sleep Program. "A very small percentage of folks have Advanced Sleep Phase Disorder (ASPD), where they naturally fall asleep around 5 p.m. to 8 p.m. and rise around 1 a.m. to 4 a.m. The opposite condition is Delayed Sleep Phase Disorder (DSPD), where the sleep time is around 2 a.m. to 6 p.m. until about 10 a.m. to 2 p.m. Of the two, DSPD is more common, and patients with this are often misdiagnosed as having insomnia since they cannot fall asleep during the 'conventional' sleep period. They have great difficulty waking up and functioning in the early part of the day (when their brain is still wanting to be in sleep mode). ASPD is more common in the elderly, and these patients often complain of early morning awakening and being unable to return to sleep."
Sleep Cycles: REM and Non-REM
Not all sleep is created equal. Our bodies go through different stages in the sleep cycle, with different physiological effects from REM (rapid eye movement) and non-REM sleep. Both stages of sleep affect the nervous, endocrine and cardiopulmonary systems. During sleep, core body temperature drops. Heart rate and diastolic blood pressure decrease by as much as 10 percent. Growth hormones, testosterone and prolactin increase, while cortisol and hormones that affect insulin and thyroid production decrease. During non-REM sleep, respiratory rate slows and blood oxygen levels decrease.
"[Non-REM sleep] is typically seen after falling asleep and initially going into non-REM sleep. About 90 minutes later, we go into REM sleep and cycle between non-REM and REM sleep every 90 minutes or so. REM sleep is where we typically dream." says Vijay M. Patel, MD, pulmonologist and sleep medicine specialist with Piedmont Newnan Hospital. "We usually spend more time in non-REM sleep during the first part of the night and more time in REM sleep in the later part of sleep. We may have two to five cycles between non-REM and REM sleep."
How important is it to experience full, uninterrupted sleep cycles, particularly REM sleep? While REM's full effects on the body are still being explored, we do know that REM plays a vital role in our physical and mental health.
"In general, a good night's sleep is very important in our overall body functions, including learning new information and consolidating that information into memories," Dr. Vijay Patel says.
Inside and Out
Healthy sleep gives the body and the mind a period of restoration. According to the National Sleep Foundation, while we rest in deep sleep, the brain builds and strengthens neuropathways, glands release and rebalance hormones, the blood supply increases and tissue growth and repair occurs. Therefore, sacrificing sleep affects mental acuity, reflexes, mood, stamina, immunity and even appearance.
"Lack of sleep is aging your body in many ways and can leave you with a dull, sallow skin look, early wrinkling and hair loss," says Dr. Bhatia. "Mentally, lack of sleep worsens anxiety, depression and attention or the ability to focus." The body needs that regular rejuvenation to maintain health and combat stresses from lifestyle and environment.
Without this downtime, David Westerman, MD, medical director of Northside Hospital Sleep Disorders Center, cautions there's "a negative impact on memory and thinking processes, mood changes, irritability, increased risk for depression and substance abuse and a negative impact on interpersonal relationships." Dr. Collop agrees, stating that "the biggest effects of sleep deprivation in studies is that on mood—more depressed and labile. Reaction time is reduced as well. Chronic sleep deprivation also seems to affect the immune system, so one may be more susceptible to infections."
The Dos and Don'ts of Good Sleep
For those without a chronic sleep disorder, a few changes to lifestyle and behaviors may greatly improve sleep. Here are some Dos and Don'ts to help you achieve the best possible night's sleep:
Do: Be consistent with bedtime and waking time.
Do: Get regular exercise, which is shown to reduce insomnia and lead to deeper, more regular sleep.
Do: Develop a bedtime routine, with 30 to 60 minutes of unwinding activities before bed—such as yoga, meditation or prayer, even a warm bath or shower to help relax.
Do: Keep the room cool, dark, quiet and uncluttered.
Do: Limit screentime for one to two hours prior to bedtime; light from TV and devices (smartphones or tablets) stimulates the pineal gland, interfering with the sleep/wake cycle.
Do: Use the bed for sleeping and sex only, not for other activities such as work or spreading out projects.
Don't: Use tobacco or other nicotine-containing products.
Don't: Have caffeine within four hours of bedtime (this includes chocolate).
Don't: Drink alcohol within one to two hours of bedtime (particularly for women).
Don't: Eat heavy or fatty late-night snacks.
Don't: Nap in the late afternoon or early evening.
Don't: Let sleep be shortchanged. Prioritize it!
And the Most Important Don't? "Don't think you can catch up on your sleep—you can only catch up on slowing down the aging process," says Dr. Bhatia. "We all need consistent, regular nightly sleep for our bodies to function optimally."
Taz Bhatia, MD, CentreSpringMD —centrespringmd.com
Nancy Collop, MD, Director of Emory Sleep Center and Professor of Medicine and Neurology, Emory University School of Medicine — emoryhealthcare.org
National Sleep Foundation — sleepfoundation.org
Hitendra Patel, MD, Medical Director of WellStar Sleep Program — wellstar.org
Vijay M. Patel, MD, FCCP, Pulmonologist and Sleep Medicine Specialist, Piedmont Newnan Hospital — piedmont.org
David E. Westerman, MD, FCCP, FAASM, Medical Director of Northside Hospital Sleep Disorders Center — northside.com