Why do we sleep?

Cedernaes explained that the new study does not refute “the fact that levels of proteins linked to neurodegeneration, such as tau, are produced at higher levels during wakefulness when neuronal activity is high.”

He noted that in animal studiesTrusted Source, such protein levels tend to rise during sleep deprivation.

In human studiesTrusted Source, researchers have observed that sleep interruption disrupts the normal regulation of proteins, specifically amyloid beta and tau proteins, which are implicated in Alzheimer’s pathogenesis.

There is a body of research suggesting “too little sleep, and poor sleep, are associated with a higher risk of neurodegeneration and specifically Alzheimer’s disease,” Cedernaes said, citing 40-year follow-up data from his own research supporting this connection.

“So even though sleep may not facilitate clearance of metabolites from the brain, there are other mechanisms through which sleep has restorative properties that contribute to healthy aging of the brain,” Cedernaes added.

Frank noted, “Our study simply removes one explanation of how there might be a connection between poor, or short, sleep and neurological disorders.”

Is there a way to clear your brain?

“Our data only show that the waking state gives improved clearance compared to being asleep or anesthetized, but we do not know what aspects of the waking state are responsible,” Frank said.

“It might be just neuronal activity. We can speculate that exercise would improve clearance further, but this has yet to be shown.”

Indeed, preliminary research suggests that physical activity may help clear metabolites from the brain, but further studies are warranted.

Cedernaes acknowledged while this remains a new area of study, sleep is often associated with better health outcomes.

“We know that a healthy lifestyle, meaning sufficient high quality sleep, a healthy diet, and sufficient amounts of physical activityTrusted Source, are all associatedTrusted Source with a lower risk of developing neurodegenerative disease later in life.”

— Jonathan Cedernaes, PhD, researcher