Taking a Sleeping Pill May Lower Levels of Key Alzheimer's Proteins in the Brain
Michelle Milliken
Past research has linked unhealthy sleep patterns with an increased risk of developing Alzheimer’s disease. Now, new research indicates that taking medications to ensure a good night’s sleep may have the opposite effect, decreasing hallmarks of Alzheimer’s in the brain.
A study recently published in the journal Annals of Neurology investigated the impacts of suvorexant, a type of sleeping pill known as an orexin inhibitor, on the accumulation of tau and amyloid beta, two proteins linked with Alzheimer’s. The team found that the pill, in higher doses, lowered the levels of both in the brain.
Dr. Brendan Lucey, the study’s senior author and director of Washington University’s Sleep Medicine Center, says, “This is a small, proof-of-concept study. It would be premature for people who are worried about developing Alzheimer’s to interpret it as a reason to start taking suvorexant every night. We don’t yet know whether long-term use is effective in staving off cognitive decline, and if it is, at what dose and for whom. Still, these results are very encouraging. This drug is already available and proven safe, and now we have evidence that it affects the levels of proteins that are critical for driving Alzheimer’s disease.”
In past research, Dr. Lucey and his colleagues linked poor sleep to higher levels of amyloid and tau in the brain. For the current study, they wanted to see if good sleep could counteract this. To investigate, the team recruited 38 cognitively healthy people between the ages of 45 and 65 to undergo a two-night sleep study. Participants either had a 10 mg dose of suvorexant, 20 mg of suvorexant, or a placebo before going to sleep at a clinical research unit.
Every two hours, for 36 hours, the researchers withdrew cerebrospinal fluid via spinal tap. The samples were taken beginning an hour before the first dose was given. Among those who had received the higher dose of suvorexant, amyloid levels dropped between 10 and 20%, while a type of tau known as hyperphosphorylated tau decreased 10 to 15%. This was compared to the placebo group. However, the same effect was not observed in the lower dose group.
Within 24 hours of the first dose, the tau levels had risen again but amyloid levels were still lower for the high dose group. When they took their second dose, though, both protein levels fell again. The team says these findings make them hopeful, as they believe lowering amyloid every day may decrease overall accumulation of plaques, and hyperphosphorylated tau is also linked with tau tangles and neuron death. Though more research is needed, the team is already expanding this work to other studies.
Dr. Lucey says, “Future studies need to have people taking these drugs for months, at least, and measuring the effect on amyloid and tau over time. We’re also going to be studying participants who are older and may still be cognitively healthy, but who already have some amyloid plaques in their brains. This study involved healthy middle-aged participants; the results may be different in an older population.”
While research is still ongoing, Dr. Lucey recommends that everyone get a good night’s sleep, or to get help from a sleep specialist if this is a struggle for them.
You can read the whole study here.
