How Sleeping Habits Affect Alzheimer’s Risk

A new study has revealed a link between poor sleep and increased Alzheimer’s disease risk. The research found that adults with normal cognitive function who experience trouble sleeping and daytime drowsiness may be more likely to develop the degenerative brain disease than their more rested counterparts.

The study, published online in Neurology, found that these sleep problems are associated with increased spinal fluid indicators of Alzheimer’s disease. Although it's not clear why poor sleep is associated with the disease, the team hypothesize that the brain does a lot of its cleaning during sleep, The New York Times reported. Without sufficient time to self-clean, brain toxins that may lead to Alzheimer’s disease have time to build up.

“Not everyone with sleep problems is destined to develop Alzheimer’s disease,” said senior author, Barbara B. Bendlin, The New York Times reported. “We’re looking at groups of people, and over the whole group we find the association of poor sleep with the markers of Alzheimer’s. But when you look at individuals, not everyone shows that pattern.”

This is not the first study to show a link between poor sleep and degenerative brain diseases. For example, past research from the University of Rochester revealed that the brains of mice clear away molecules during sleep that could potentially cause damage and degenerate the brain. As the mice slept, their brains actually changed shape, expanding to allow them to better flush out these toxins that had built up during the day, The Huffington Post reported. Based on this, the researchers determined that poor sleep in humans could accelerate the effects of degenerative brain diseases such as Alzheimer’s and Parkinson's.

“Think about a fish tank,” Dr. Maiken Nedergaard, a Danish biologist who had previously led research on sleep’s purpose in the brain, told The New York Times. “If you have a tank and no filter, the fish will eventually die. So, how do the brain cells get rid of their waste? Where is their filter?”

Finding out what causes Alzheimer’s could be critical to stopping the disease as early as possible, before irreversible damage has been done. Research from earlier this year may have revealed another clue in Alzheimer’s early start; it found that signs of brain plaque buildup can be seen in patients as early as 10 years before they begin to experience disease symptoms. The team hope this will help doctors find and treat patients who may be at highest risk for this disease early, and also could help them figure out a way to clear these brain plaques before they build up in quantities great enough to cause symptoms.

Source: Sprecher KE, Koscik RL, Carlsson CM, et al. Poor sleep is associated with CSF biomarkers of amyloid pathology in cognitively normal adults. Neurology . 2017