Poor Sleep and Alzheimer’s…the Washington University Study. Kathie Brown Roberts P.C.

Washington University in St. Louis


In the second study, published in the journal Brain, a team from Washington University in St. Louis reported that sleep disruption raised levels of amyloid, the protein that clogs the brains of Alzheimer’s patients. They believe that interrupted sleep may allow too much of the compounds, amyloid and tau, to build up and that sleep might help the body clear them away.


In this study, the team allowed their group of 17 healthy adults to sleep a normal amount of time but half were prevented from getting deep sleep, called slow-wave sleep. In the mornings, their spinal fluid was analyzed. Those who had their slow-wave sleep disrupted had an increase in their amyloid levels by about 10%. The volunteers also wore sleep monitors to measure their sleep at home. Those who slept poorly for a week at home had measurably higher levels of a second Alzheimer’s associated protein called tau.


Amyloid is naturally produced in the brain and researchers know it can cause clogs called plaques. People with more plaques often have memory and thinking problems and dementia but not always, so the amyloid link is not yet entirely clear.


Dr. Yo-El S. Ju, who led this study, thinks that interrupted sleep leads to increased brain activity and increased amyloid production. Amyloid is released by brain cells all the time when they fire their synapses, but they don’t release the amyloid when they rest. Dr. Ju thinks the brain may clear out excess levels of amyloid during deep sleep.


“When people are in a nice, deep sleep, they get a period of time when, with the normal clearance mechanisms working, the levels of amyloid decrease. If levels are increased over years, they are more likely to cause the clumps, called plaques, which don’t dissolve.”


Studies in mice show it takes only an excess of about 10 percent of amyloid to cause amyloid plaques to form. This study showed that just one night of interrupted sleep can increase amyloid levels by 10 percent.


Dr. Ju’s team will next study whether treating obstructive sleep apnea, a common cause of sleep disruption, will improve people’s slow-wave sleep and affect amyloid levels.