Impaired sleep over many years may be a risk factor for some forms of dementia
DEAR MAYO CLINIC: Is it true that sleep deprivation eventually could lead to Alzheimer’s disease?
There have been a number of studies looking at the effect of sleep on disorders that impair cognitive function, such as Alzheimer’s disease. Although no research has shown a clear link between sleep deprivation and Alzheimer’s, it is possible that impaired sleep over many years may put you at higher risk for some forms of dementia, including Alzheimer’s disease.
Alzheimer’s disease is a progressive type of dementia that impairs memory, thinking and social abilities severely enough to interfere with daily functioning. Sleep problems are a common component of Alzheimer’s disease. Alzheimer’s disease can disrupt the normal sleep-wake cycle, causing daytime drowsiness and nighttime restlessness. And, as Alzheimer’s gets worse over time, these sleep disturbances often get worse, too. For many people with the disease, round-the-clock naps eventually replace deep, restorative nighttime sleep.
The question of whether a lack of healthy sleep could contribute to the development of Alzheimer’s disease is under investigation. Although the exact cause of Alzheimer’s isn’t well-understood, researchers believe that a buildup of an abnormal protein called beta-amyloid in the brain contributes to the disease. As it accumulates in the brain, beta-amyloid appears to damage or destroy brain cells by interfering with communication among cells.
When you get a good night’s rest, particularly when you’re in deep sleep, research has shown that beta-amyloid is cleared from your brain. If your body doesn’t get the quality sleep it needs, over time, beta-amyloid may not be adequately cleared from the brain. It’s possible that could enhance the buildup of this abnormal protein, thereby raising the risk of Alzheimer’s disease.
The Centers for Disease Control and Prevention recommends adults get an average of at least seven hours of sleep a night. If you struggle to get that much sleep, consider incorporating some basic sleep tips into your routines that may improve the quantity and quality of your sleep.
One of the best steps you can take to encourage better sleep is to set a sleep schedule and stick to it. Your bedtime and wake-up time don’t have to be exactly the same every day, but they should be generally consistent. For example, try to limit the difference in your sleep schedule on weeknights and weekends to no more than one hour. Staying on a schedule reinforces your body’s sleep-wake cycle.
Set up your bedroom environment to help you sleep. For most people, that means keeping it dark, cool and quiet. For the best sleep, turn off all electronic devices at least 30 to 60 minutes before you got to bed. This gives your brain time to relax and wind down, making timely sleep more likely. Keep computers and TVs out of your bedroom, and shut down cellphones at night, storing them in another room.
Leading a healthy, active lifestyle can promote healthy sleep, too. Eat a well-balanced diet. Keep alcohol to a minimum. Although alcohol can make it easier to fall asleep faster, it makes it harder to stay asleep. Exercise regularly. If you have a sleep disorder, such as sleep apnea, restless leg syndrome or insomnia, have those conditions evaluated and treated.
Getting a good night’s sleep is important. Not only could long-term sleep deprivation raise your risk for dementia, research has shown that, over time, people who don’t sleep enough also may be at an increased risk for other health problems, including high blood pressure, heart disease and diabetes. -- Ronald Petersen, M.D., Ph.D., Alzheimer’s Disease Research Center, Mayo Clinic, Rochester.