Sleep may matter years before Alzheimer’s symptoms appear

A few late nights may not seem like much, but years of poor sleep could matter more than many people realise. According to neurologist Dr Mohamad Imran Idris, brain changes associated with Alzheimer’s disease could begin 15 to 20 years before noticeable memory problems appear.

This, he told Bernama, is why long-term sleep habits deserve attention much earlier in life.

“Changes in the brain start years before somebody actually develops dementia – meaning 20 years before they start having severe memory problems, you can already see microscopic changes occurring,” he explained.

Imran pointed out the common misconception that lost sleep during the week can simply be “repaid” by sleeping much longer on 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.

During deep sleep, the brain is involvedd in clearing metabolic waste, cellular debris and inflammatory by-products that accumulate while a person is awake. Consistently getting too little sleep can reduce that recovery time and may contribute to poorer brain health over the long term.

How much sleep is enough?

Imran said research points to a “U-shaped relationship” between sleep duration and dementia risk. For most adults, around seven to eight hours of sleep a night is considered a useful target 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 outlined.

That does not mean sleeping longer causes dementia. Rather, a major change in sleep pattern can sometimes be a sign that something else is going on.

Changes may also appear years before a formal diagnosis. One example is REM sleep behaviour disorder, in which a person loses the normal muscle paralysis that occurs during dreaming and may shout, punch or kick while asleep.

While not everyone with this condition will develop dementia, Imran said persistent changes in sleep should not be ignored.

Gender can also play a role in Alzheimer’s risk: statistics show that among people over 65, there are roughly twice as many women as men living with Alzheimer’s disease.

Age remains another important factor. In Malaysia, health ministry surveys have indicated that dementia affects about 10% of people over 60, with prevalence rising sharply among those aged 80 and above.

According to Imran, other measures that may help support long-term brain health include:

• managing blood pressure and cardiovascular health;
• staying physically active;
• keeping the brain engaged through mentally stimulating activities;
• avoiding smoking;
• reducing exposure to air pollution where possible; and
  maintaining regular social contact and engagement.
• Advances in diagnosis are also changing how Alzheimer’s is detected and managed, with newer blood-based biomarkers and disease-modifying treatments offering more options than were available in the past.

The key, Imran noted, is not to wait until memory problems become severe.

“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.

Subscribe to our newsletter and get news delivered to your mailbox.