Brain changes linked to Alzheimer’s disease can begin 15 to 20 years before noticeable memory problems emerge, highlighting the importance of maintaining healthy sleep habits over the long term, a neurologist said.
Sunway Medical Centre, Sunway City consultant neurologist Dr Mohamad Imran Idris said consistently poor sleep over months and years could increase metabolic stress on the brain and contribute to neurodegenerative risks.
“Changes in the brain start 15 to 20 years before somebody actually develops dementia, meaning 20 years before they start having severe memory problems, you can already see microscopic changes occurring,” he told Bernama in an exclusive interview.
He also warned against the belief that lost sleep during the working week could simply be recovered by sleeping for longer at weekends.
“Sleep regularity is what matters because pulling four-hour nights and trying to compensate with 12-hour weekend sleep simply does not work biologically to clear accumulated brain inflammation,” he said.
According to Dr Mohamad Imran, the brain uses deep sleep to clear metabolic waste, cellular debris and inflammation that build up during waking hours.
Chronic sleep deprivation can reduce this recovery period and, over time, increase the risk of cognitive decline, he said.
He noted that research showed a U-shaped relationship between sleep duration and dementia risk, with seven to eight hours of uninterrupted sleep a night representing the optimal range for brain recovery.
“Too little sleep increases the risk of dementia, but too much sleep can also reflect that someone is already developing it, especially if someone who used to sleep normally suddenly begins sleeping for much longer hours or stays in bed all day,” he said.
Dr Mohamad Imran also highlighted differences in dementia risk by gender, noting that statistics indicate there are about twice as many women as men aged over 65 living with Alzheimer’s disease.
He said subtle non-cognitive symptoms could also appear up to a decade before a formal diagnosis, including REM Sleep Behaviour Disorder (RBD).
The condition occurs when the normal muscle paralysis associated with dreaming does not take place, causing individuals to physically act out vivid dreams by shouting, punching or kicking while asleep.
In Malaysia, dementia prevalence has been rising alongside the country’s ageing population. Health Ministry surveys indicate that about 10 per cent of Malaysians aged over 60 have dementia, with the figure increasing to 33 per cent among those aged 80 and above.
Despite the growing prevalence, Dr Mohamad Imran said advances in diagnosis, including blood-based biomarkers and newly approved disease-modifying therapies, have enabled specialists to slow the physical progression of Alzheimer’s disease.
He also encouraged people to adopt healthier lifestyles, including managing cardiovascular health, exercising regularly, engaging in activities that stimulate the brain, avoiding smoking, reducing exposure to air pollution and maintaining social connections.
“If you notice a persistent change in your sleeping patterns or are becoming unusually forgetful, see a doctor early, because waiting until memory problems prevent you from recognising family members is often too late,” he said.
World Alzheimer’s Day, observed annually on Sept 21, continues to provide a platform for raising awareness of the disease and encouraging early medical intervention.
