"Poor sleep is associated with higher levels of two Alzheimer's-associated proteins", said David M. Holtzman, a neurology professor from Washington University School of Medicine, in a statement. Holtzman, Washington University sleep medicine physician Yo-El Ju and colleagues recruited 17 volunteers, all healthy adults between ages 35 and 65, who had no sleep disorders.
Each time the participants drifted into deep sleep, a beeping monitor would rouse them out of it and into lighter sleep. "For example, disrupted sleep or lack of sleep may lead to amyloid plaque buildup because the brain's clearance system kicks into action during sleep". For example, there was no link between biological markers in the spinal fluid and obstructive sleep apnea. "I don't think people should worry about Alzheimer's disease after one bad night".
Have you ever slept all night - only to wake up in the morning feeling exhausted?
Ju cautioned that it's not yet certain whether simply getting better sleep will improve your Alzheimer's prospects.
One of the functions of sleep is to wash neurotoxins from the brain, including beta-amyloid proteins, which other research has shown can worsen sleep.
Scientists at the University of Wisconsin-Madison looked at the spinal fluid of 101 people with an average age of 63, and found that those who reported poor sleep quality had, on average, more markers of Alzheimer's disease - including amyloid and tau build-ups, brain-cell damage and inflammation.
Bendlin did note that, "It's still unclear if sleep may affect the development of the disease or if the disease affects the quality of sleep". It shows that poor sleep leads to an increase in harmful compounds that can cause dementia. "These are good sleepers", Ju says.
Holtzman and the study's co-first author, Dr Yo-El Ju, invited nearly 20 participants aged between 35 and 65 into the School of Medicine's sleep room for a night. The sounds usually didn't wake the people up but kept them from getting any slow-wave sleep.
"It's important to identify modifiable risk factors for Alzheimer's given that estimates suggest that delaying the onset of Alzheimer's disease in people by a mere 5 years could reduce the number of cases we see in the next 30 years by 5.7 million and save $367 billion in health care spending", says Bendlin.