Lack of sleep and Alzheimer’s risk
Can lack of sleep cause Alzheimer’s? Recent studies confirm what many of us already know: sleep gets worse as we age. Starting around middle-aged and older, people often wake more frequently at night, sleep less deeply and wake too early in the morning. Could these sleeping issues be putting us at risk for cognitive decline or even Alzheimer’s disease?
What is sleep deprivation’s link with dementia?
One night of poor sleep can cause issues with your thinking the next day. But many months or years of inadequate sleep may lead to more serious and chronic problems with your thinking. For example, one study found that people who sleep less than 4 hours a night may struggle more with their thinking, learning, and memory abilities.
Research is ongoing, but so far, a history of sleep trouble does seem to increase the risk of dementia for some people. One study suggests sleep deprivation could increase your dementia risk by 20%. In middle age, even getting less than 6 hours of sleep per night may increase your dementia risk in the future.
Scientists are beginning to probe the complex relationship between the brain changes involved in poor sleep and those in very early-stage Alzheimer’s. People who slept six hours or less per night in their 50s and 60s were more likely to develop dementia later in life. The findings suggest that inadequate sleep duration could increase dementia risk and emphasizes the importance of good sleep habits.
Nearly 60 percent of older adults have some kind of chronic sleep disturbance.
It’s long been known that people with Alzheimer’s often have sleep difficulties. Now scientists are probing the link between sleep and Alzheimer’s earlier in the disease process and in cognitively normal adults. They wonder if improving sleep with existing treatments might help memory and other cognitive functions—and perhaps delay or prevent Alzheimer’s.
Which comes first, poor sleep or Alzheimer’s?
The chicken-and-egg question is whether Alzheimer’s-related brain changes lead to poor sleep, or whether poor sleep somehow contributes to Alzheimer’s. Scientists believe the answer may be both.
Findings show that brain activity induced by poor sleep may influence Alzheimer’s-related brain changes, which begin years before memory loss and other disease symptoms appear.
What’s the connection between sleep and Alzheimer’s?
Some recent studies suggest that poor sleep contributes to abnormal levels of beta-amyloid protein in the brain, which in turn leads to the amyloid plaques found in the Alzheimer’s brain. These plaques might then affect sleep-related brain regions, further disrupting sleep.
Studies in humans have also addressed the relationship between sleep and biomarkers of Alzheimer’s disease. One study found that in cognitively normal older adults, poor sleep quality (more time awake at night and more daytime naps) was associated with lower beta-amyloid levels in cerebrospinal fluid, a preclinical sign of Alzheimer’s. Another study, by researchers at NIA and Johns Hopkins University (Baltimore, MD), found that healthy older adults who reported short sleep duration and poor sleep quality had more beta-amyloid in the brain than those without such sleep problems.
While many adults have problems sleeping, people with dementia often have an even harder time. Sleep disturbance may affect up to 25% of people with mild to moderate dementia and 50% of people with severe dementia. Sleep disturbances tend to get worse as dementia progresses in severity.
Obstructive sleep apnea is also more common in people with Alzheimer’s disease. This potentially serious sleep disorder that causes breathing to repeatedly stop and start during sleep, possibly leading to a host of other health issues.
More studies to examine the value of a good night’s sleep in delaying or preventing Alzheimer’s disease are underway.
The Good News
Quality sleep is known to play an important role in concentration and learning, as well as mood and overall health. Quality sleep is something that can be improved. People with sleep problems should consult a sleep medicine physician so that they can function at their best. No matter what your age!