Missing out on sleep can have serious consequences for the body and the brain—including possibly setting the stage for cognitive decline and Alzheimer’s disease (AD), according to a new study. However, by learning a few sensible sleep strategies, you can improve the likelihood of a brain-healthy night’s rest.
Sleep disturbances—having difficulty falling asleep or staying asleep, or experiencing sleep that is not restorative—are common in people with mild cognitive impairment (MCI) and AD. However, whether sleep disturbance is a result of neurodegenerative processes or a possible cause is uncertain. A study published online March 11, 2013 in JAMA Neurology suggests that it may be both. Researchers fitted 142 cognitively normal people, whose average age was 65, with a device that recorded their movements while they slept, providing an indication of both their total sleep time and their sleep efficiency (how much time in bed they spent actually sleeping). The participants also gave a sample of cerebrospinal fluid to be analyzed for toxic beta-amyloid protein—a hallmark of AD—as an indication of amyloid deposition in the brain.
WHAT YOU CAN DO
Keep a sleep diary and seek help from your doctor for these symptoms of disturbed sleep if you cannot resolve them on your own:
- Difficulty falling asleep
- Frequent waking and difficulty going back to sleep
- Waking too early
- Unrefreshing sleep
- Snoring or brief halts in breathing while asleep
- Difficulty waking when the alarm clock rings, or morning fatigue
- Daytime sleepiness, or falling asleep at inappropriate times
- Difficulty concentrating or functioning because of fatigue
- Needing drugs or alcohol to fall asleep, or caffeine to stay awake
The scientists found that the 32 participants with the strongest indications of amyloid deposition in the brain were also those who slept less efficiently, took more daytime naps, and woke up more during the night over the two-week study period. Previous studies by the same researchers found that sleep deprivation in mice leads to the buildup of amyloid in the brain, and that increasing the animals’ sleep time reduces amyloid accumulation. Another study showed that removing amyloid plaque from the brains of mice restored normal sleep/wake patterns. The authors say their findings may indicate the existence of an interrelationship between sleep and amyloid deposition, in which each factor influences the other in a vicious cycle that promotes negative brain changes. If further studies strengthen the view that sleep disruption helps increase risk for AD, this would provide “an even stronger motivation to identify and treat individuals with sleep disorders,” the study authors said.
Brain and Body
“This study does not suggest that disrupted sleep causes AD, but merely that the two issues are associated with one another,” says John Winkelman, MD, PhD, of the Division of Sleep Medicine at Brigham and Women’s Hospital in Boston. “Further investigation will be needed to determine the precise relationship between sleep disruption and AD. However, this research adds to a long list of possible harmful brain effects linked with chronic sleep disturbance, including the impairment of essential brain functions, such as thinking, decision-making, attention, the ability to accomplish complex tasks, verbal fluency, memory, and maintaining mood stability.”
The list goes on: Sleep problems may interfere with important brain processes that are accomplished during sleep, such as consolidating and storing newly acquired information, making memories resistant to interference, promoting the creation of new brain cells, and repairing brain cells and strengthening their connections to other cells. Mental disorders such as depression and anxiety are also associated with chronic sleep disturbances, Dr. Winkelman says.
“Chronic sleep problems have been linked to heightened vulnerability to physical problems that affect the brain, such as infection and inflammation, high blood pressure, heart disease, and stroke,” he points out. “Lack of sleep also appears to interfere with the body’s ability to manage insulin and raises the risk for obesity and diabetes, both of which have been linked to memory impairment.”
About 40 million Americans suffer from chronic sleep disorders each year, according to a National Institutes of Health estimate, and many are older adults. If you are one of them, don’t just assume that your sleep problems are a normal part of aging.
“Sleep studies looking at older adults have not identified age as an independent predictor of insomnia and other sleep problems,” Dr. Winkelman says. “But a number of issues associated with increasing age—such as social isolation, mental illness, lack of exercise, use of medications, and more frequent medical conditions—may negatively affect sleep quality. These are factors people can do something about.”
A prerequisite for satisfying sleep is practicing good “sleep hygiene,” Dr. Winkelman says. Some suggestions:
▶ Adhere to a regular schedule of bed time and especially wake-up time.
▶ Engage in regular exercise.
▶ End your day with a relaxing hour of quiet activity before bedtime.
▶ Since napping can interfere with your need for sleep at night, avoid napping or limit daytime dozes to morning naps of an hour or less.
▶ Use your bed only for sleep or sex (e.g., watch TV or read elsewhere)
▶ Cut down on or eliminate caffeine, alcohol and nicotine, and avoid heavy meals within four hours of bedtime.
Tailor these general rules to suit your individual needs, and if they don’t work, consider seeking professional help, Dr. Winkelman advises. Prepare for your doctor’s visit beforehand by identifying specific problems that interfere with your sleep. Your doctor can help you get treatment for any conditions that are associated with sleep problems, such as depression, anxiety, pain, frequent urination, Parkinson’s disease, stroke, heart disease, or sleep disorders such as sleep apnea (characterized by temporary interruptions of breathing during sleep and often accompanied by loud snoring) and restless leg syndrome (characterized by a need to move the legs at night that leads to difficulty falling asleep). In consultation with your doctor, review your medications to determine whether any side effects might be interfering with your sleep.
“If you continue to have difficulty falling asleep or staying asleep, referral to a sleep specialist may be in order,” Dr. Winkelman says.
“With the proper diagnosis and treatment, your quality of sleep—and your brain function—may well improve.”