A significant marker for Alzheimer's disease has been seen to rise and fall to reflect sleeping pattern.
The body finishes clearing away amyloid beta during the periods of relative brain inactivity provided by sleep, according to research published in journal Neurology.
Amyloid beta is cleared through the spinal fluid, as well as by other mechanisms.
This pattern was seen to be strongest in healthy young people, while the highs and lows of amyloid beta levels begin to flatten in older adults.
In seniors with brain plaques linked to Alzheimer's disease, levels of the marker remain at an almost constant level.
Findings indicate that inadequate sleep could put the individual at an increased risk of developing Alzheimer's.
The University of Washington's Stephen Duntley said: "We've known for some time that significant sleep deprivation has negative effects on cognitive function comparable to that of alcohol intoxication.
"This connection to Alzheimer's disease isn't confirmed yet in humans, but it could be very important."
Find out more about Alzheimer's disease care at Barchester homes