Tossing and turning and grappling with restless nights? New research suggests that a poor night’s sleep doesn’t just make you dreary-eyed the next day – in the long run, disrupted sleep could be a risk factor for Alzheimer’s or other neurological diseases.
Scientists out of the Washington University School of Medicine suggest that for middle-aged people, disrupted sleep causes an increase in a brain protein called amyloid beta that’s tied to Alzheimer’s disease.
Just one poor night’s sleep is enough to see an increase while a week’s worth of tossing and turning led to an increase in another brain plaque called tau – its buildup in the brain has been tied to dementia, too.
“We showed that poor sleep is associated with higher levels of two Alzheimer’s-associated proteins. We think that perhaps chronic poor sleep during middle age may increase the risk of Alzheimer’s later in life,” Dr. David Holtzman, the study’s senior author, said.
“The main concern is people who have chronic sleep problems. I think that may lead to chronically elevated amyloid levels, which animal studies have shown lead to increased risk of amyloid plaques and Alzheimer’s,” Dr. Yo-El Ju, the study’s first co-author, said.
The pair has looked at poor sleep and its effect on cognition in the past: in previous research, they learned, for example, that people with sleep apnea are at a greater risk of developing mild cognitive impairment about a decade before people without the sleep disorder.
(Mild cognitive impairment is an early warning sign for Alzheimer’s.)
This time around, the researchers worked with 17 healthy adults between 35 to 65 years old. They didn’t have any sleep problems or cognitive impairments. The participants wore activity monitors on their wrists for two weeks that measured how much sleep they were getting.
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They also spent a few nights in a dark, soundproof, climate-controlled room, as electrodes on their scalp monitored brain waves.
Half of the group dealt with sleep disturbances during the night – a beeping noise that grew louder and louder would pull them out of sleep. A month later, the groups were reversed.
Turns out, the researchers learned that each participants’ amyloid beta levels increased by about 10 per cent after a single night of interrupted sleep.
If they slept poorly at home, their tau levels would spike.
One night, or even a week, of poor sleep doesn’t have much of an effect on overall risk of developing Alzheimer’s disease, the experts say. It’s chronic sleeping problems that could be an issue.
About 25,000 new cases of dementia are diagnosed each year, according to the Alzheimer Society. It estimates that 564,000 Canadians have dementia right now.
By 2031, in just 14 years, it’s warning that 937,000 Canadians will have dementia.
As many as 50 per cent of Canadians with dementia are not diagnosed early enough, losing valuable time when intervention can help these people with managing their daily lives.
The Alzheimer Society documents a list of 10 signs to watch for:
- Memory loss affecting day-to-day abilities – forgetting things often or struggling to retain new information.
- Difficulty performing familiar tasks – forgetting how to do something you’ve been doing your whole life, such as preparing a meal or getting dressed.
- Problems with language – forgetting words or substituting words that don’t fit the context.
- Disorientation in time and space – not knowing what day of the week it is or getting lost in a familiar place.
- Impaired judgment – not recognizing a medical problem that needs attention or wearing light clothing on a cold day.
- Problems with abstract thinking – not understanding what numbers signify on a calculator, for example, or how they’re used.
- Misplacing things – putting things in strange places, like an iron in the freezer or a wristwatch in the sugar bowl.
- Changes in mood and behaviour – exhibiting severe mood swings from being easy-going to quick-tempered.
- Changes in personality – behaving out of character such as feeling paranoid or threatened.
- Loss of initiative – losing interest in friends, family and favourite activities.