A common sleeping pill can slash the risk of Alzheimer’s by reducing the build-up of harmful proteins in the brain, according to a study.
Scientists at Washington University in St Louis, Missouri tracked the progress of 38 people using suvorexant – a drug that aids sleep – for two nights.
Alzheimer’s is caused by a build-up of the proteins in the brain, including amyloid and tau. Scientists believe that removing these sticky deposits from the brain can stem the advance of Alzheimer’s.
Researchers found that those who took the highest dose experienced a drop of up to a fifth in the amyloid levels in their spinal fluid the next day, compared with those who received a placebo.
Sleep disturbances can be an early sign of Alzheimer’s and the disease itself can reduce sleep quality.
Brendan Lucey, an associate professor of neurology and director of Washington University’s Sleep Medicine Center, said that patients should not begin taking the pills every night as the research is still at an early stage.
He added: “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.”
The drug works by blocking the production of Orexin, a natural molecule that promotes wakefulness.
When Orexin is blocked, it causes people to fall asleep.
The study involved 38 participants aged 45 to 65 with no cognitive impairments. Each was asked to sleep for two nights at a university research unit.
One group was given a low 10mg dose of suvorexant, another was given 20mg and a third was given a placebo at 9pm before going to sleep.
Amyloid levels were found to have dropped between 10 and 20 per cent in those who received the highest dose.
Tau levels also dropped by up to 15 per cent – but there was no fall in the low-dose group.
Dr Lucey added: “If we can lower amyloid every day, we think the accumulation of amyloid plaques in the brain will decrease over time.
“I’m hopeful that we will eventually develop drugs that take advantage of the link between sleep and Alzheimer’s to prevent cognitive decline.
“At this point, the best advice I can give is to get a good night’s sleep if you can.”
Around 944,000 Britons are currently living with dementia, which is caused by Alzheimer’s. Experts predict the figure will pass 1 million by the end of the decade.
Suvorexant, which is sold under the name Belsomra, is available in the United States, Japan and Australia but has not yet been approved in the UK.
