specialty focus
The slow lane
Breakthrough study finds deep sleep can stave off Alzheimer ’ s .
By Elise Hartevelt
New research confirms our daily sleep habits , age and lifestyle determines our risk of Alzheimer ’ s in the future .
The Australian-first study used acoustic stimulation technology to enhance slow wave sleep in older people to boost the clearance of toxins in the brain associated with the disease .
Slow wave sleep , a very deep state of sleep , improves memory consolidation and removes harmful byproducts from the brain .
“ Slow wave sleep is key in clearing amyloid every night ,” associate professor Clare Anderson from Monash University says .
“ During the day , when we ’ re using our brain , it creates different byproducts .
“ Some of those are good , and some of those are not so good .
“ And one that ’ s not so good is amyloidbeta peptide .”
Alzheimer ’ s is one of the long-term neurodegenerative diseases under the umbrella term dementia .
Although dementia is common – 1 in 15 Australians over 65 are affected – it ’ s not considered a normal part of ageing .
Research focuses on the protein amyloid-beta peptide , an off-script version of its predecessor , which can clump together and form plaques that disrupt the communication between nerve cells .
While it ’ s normal for a healthy brain to have some levels of amyloid as it ’ s essential in neural growth and repair , an excess of amyloid is harmful .
“ When that happens , it initiates this cascade of brain changes towards a disease like dementia ,” Anderson says .
“ At the moment , we don ’ t know whether that ’ s because people with Alzheimer ’ s produce too much or whether it ’ s not cleared sufficiently by the brain .
“ So we ’ re trying to promote the clearance of amyloid during sleep , using slow waves to stave off or delay any of those brain changes that are the beginning of Alzheimer ’ s .”
The problem is that slow wave sleep significantly lessens as we age .
About 20 per cent of a 20-year-old ’ s sleep consists of slow wave , whereas someone at age 60 only has 4 to 5 per cent .
“ We ’ re seeing slow wave sleep decrease by 2 to 3 per cent per decade ,” Anderson says .
“ As we lose this type of sleepwave , we ’ re also losing the capacity to have a good and strong memory and brain health .
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The more you use your brain during the day , the more slow wave sleep you ’ ll have .
“ So we ’ re attempting to restore slow wave sleep to when we were in our 20s and 30s .”
Similar to rocking a baby to sleep , adults can promote this type of brainwave by rhythmically falling asleep .
“ But rocking yourself to sleep in , for example , a hammock , is not something everyone has daily access to , so we ’ re using an acoustic simulation approach .”
When someone starts to show slow waves during sleep , the technology delivers a quiet but audible tone which enhances the wave .
The tone triggers the waveform to become stronger and produce more similar waveforms .
“ During this phase , the brain is most receptive to stimulation ,” Anderson says .
“ For every slow wave an older person has , we boost it , and then we create more , so they ’ ll have the same waveform as somebody much younger .”
Anderson ’ s research is backed by a rising number of global studies confirming slow wave sleep as a promising prevention method against Alzheimer ’ s .
The United States already has devices on the market , such as Philip ’ s EEG-based wearable headband , that also uses sound .
But Anderson emphasises that we don ’ t need to rely on technology to promote slow wave sleep .
“ Being active , performing cognitive tasks , staying socially engaged and learning new things have the same effect ,” she says .
“ The more you use your brain during the day , the more slow wave sleep you ’ ll have at night .” Her research , ‘ Sleep , Circadian and Ageing ’, was recently awarded Faye Williams Innovation Grant funding worth $ 375,000 .
Anderson hopes the program will prove the significance of sleep in preventing dementia . “ By the end of the study , I ’ d like to know whether deep wave sleep is only preventative or if it also works when someone already has amyloid buildup ,” she says .
“ We know that around 50 % of the risk of Alzheimer ’ s is due to modifiable risk factors .
“ There are nine very clear modifiable risk factors , and I strongly believe sleep is the 10th one .” ■ agedcareinsite . com . au 21