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Sleep and Dementia – What’s the Link?

Sleep and dementia - What's the link? Woman experiencing sleep deprivation

Do you struggle to get a good night’s sleep? You’re not alone.

There are many reasons why people have trouble sleeping well – especially as we get older, but have you ever considered there could be a link between sleep and dementia? These include everything from an unhealthy lifestyle, poor sleep hygiene, stress-related insomnia, snoring, obstructive sleep apnoea, menopause in women, prostate problems in men, pain and discomfort from conditions including gastroesophageal reflux and arthritis, and many more. 

Why is it an issue? The ramifications of getting inadequate or poor-quality sleep can be significant – and are much worse than just being tired and grumpy the next day.

We all need to get enough, good-quality sleep for optimal physical health as well as brain function. Sleeping well most of the time is critical for memory, learning, mood, and decision-making, and reduces the risk of developing dementia as we get older. 

Scientists have long understood that people with dementia have issues with their sleep. What they have discovered more recently is that chronic, poor-quality sleep from as young as middle age can also increase a person’s risk of developing dementia.


What is Dementia?

Dementia is a progressive medical condition by which brain function is lost. It is not reversible and currently, it has no cure. Dementia can impact numerous cognitive processes including language skills, memory, problem-solving and decision-making skills, personality, behaviour, and more. 

In a person with dementia, their brain cells no longer function properly as well as dying off more quickly than is expected due to the normal ageing process. 

In New Zealand in 2022 (source):

  • Almost 70,000 New Zealanders are living with dementia
  • 30% more women than men are impacted by dementia
  • Dementia diagnoses are increasing more quickly in Maori, Pasifika, and Asian NZ populations than in European NZ populations
  • By 2050, it’s expected that there will be 170,000 New Zealanders living with the condition
  • 80% of people in NZ know or knew someone living with dementia
  • Dementia has cost NZ $2.5billion and this is projected to rise to $5.9b by 2050


Dementia Causes

Dementia is caused by damage to or loss of neurons (nerve cells) in the brain and the connections between these. How it will affect people depends on which part/s of the brain is impacted and how severe the disruptions to nerve activity are. 

There are different types of dementia, and most are irreversible and worsen over time.

The most common dementias include:

  1. Alzheimer’s disease can occasionally be caused by a gene mutation; parents can pass this on to their children. Most cases, however, are not hereditary.

    Alzheimer’s disease represents 60-80% of dementia and occurs when protein clumps and tangles called plaques develop in the brain. These plaques damage healthy fibres and nerve cells in the brain. People with Alzheimer’s disease commonly experience memory problems, disorientation, social withdrawal, agitation, and issues with comprehension, speech, writing, judgement, and daily tasks.

  2. Vascular dementia is caused when the brain’s blood vessels become damaged. Common signs include focus, concentration and focus issues and difficulty thinking clearly.

  3. Lewy Body dementia is characterised by abnormal protein clumps in the brain. Many symptoms can arise including sleep issues, hallucinations, and tremors.

  4. Frontotemporal dementia happens when neurons and their connections in the frontal and temporal lobes break down. Personality changes occur alongside issues with behaviour, judgement, and thinking ability.

Scientists are yet to fully understand what triggers the changes that cause dementia, but they have determined that getting poor quality or inadequate amounts of sleep from as early as middle age may increase the risk of developing the disease. 

People are 30% more likely to develop dementia in old age if they average six (or fewer) hours of sleep per night in their 50s and 60s.

As such, certain sleep disorders have been linked to dementia. These include:

  • Sleeping too much or too little – sleeping less than 7 hours or more than 9 hours per night.

  • Insomnia – dementia is much more common in people who experience primary insomnia, especially before middle age (this type of insomnia is not caused by another issue such as depression or drug use).

  • Circadian Rhythm Issues – these disruptions in the normal sleep-wake cycle are very common in people with dementia.

  • Obstructive Sleep Apnoea (OSA)obstructive sleep apnoea causes disruptions to sleep, many times a night, and leads to major health risks including earlier-onset dementia.

  • Snoring compromises sleep and may increase dementia risks.

  • REM Behaviour Disorder (RBD) – causes you to move around during REM (dreaming) sleep, making you more likely to wake up prematurely. This condition is common in people with Lewy Body dementia.

Who does Dementia Affect? 

Most people believe that dementia is a geriatric, “senile” disease. The risk of developing it, however, begins to rise from middle age, and dementia is not a normal consequence of being very old. Dementia is rarely seen in people under 60, but it can and does occur.  The risk, for example, of being diagnosed with Alzheimer’s disease, doubles every five years after the age of 65.

Sleep and Dementia – what’s the Link?

Sleep problems are very common in people with dementia. Sleep disturbances are distressing for dementia sufferers and poor quality sleep makes their symptoms worse. 

Chronically disturbed sleep may be an early sign of dementia. Scientists are working to understand whether disturbed sleep causes dementia or whether dementia causes disturbed sleep – or both.  

  • Sleep patterns change as a normal part of ageing
  • Sleep is essential for brain function, including memory formation and storage
  • Inadequate sleep causes physical changes in the brain, including the build-up of brain plaques 
  • Dementia compromises critical sleep-wake cycles
  • The suprachiasmatic nucleus (SCN, which manages circadian rhythms, displays cell damage and reduced activity in people with Alzheimer’s disease.

Tips to Improve Sleep 

Improving sleep quality in middle age is an important strategy to help prevent dementia later in life.

  • Consult with your doctor if you:
    • Don’t get enough sleep
    • Are sleepy during the day
    • Need to nap regularly
    • Have trouble falling asleep at night
    • Wake a lot through the night
    • Your sleep is disrupted by chronic pain
    • Suspect you may have obstructive sleep apnoea
    • Snore habitually
    • Are a woman suffering menopause symptoms
    • Are a man experiencing prostate issues
    • Suffer from gastroesophageal reflux at night
    • Feel agitated in the evening
    • Have restless leg syndrome
    • Experience nightmares or disruptive vivid dreams

  • Implement positive lifestyle changes.

  • Address your snoring.
  • Try to maintain a regular sleep schedule.
  • Avoid caffeine, alcohol, and nicotine.
  • Be physically active and aim to spend 10 minutes a day in the sun.

  • Maintain a healthy weight.

  • Avoid electronic devices and harsh lighting within 2 hours of bedtime.

There is no known cure for dementia. There are ways to manage the issue which, if implemented early and consistently, may help to slow its progression. 

Improving sleep quality is very important to help slow cognitive decline and troublesome symptoms in people with dementia.


Sleep Better – Stop Snoring!

Snoring can be disastrous for your sleep quality! Even non-sleep-apnoea snoring poses a risk to your long-term health and wellbeing.

ApneaRx is a fantastic solution to help sufferers of mild to moderate sleep apnea and snoring enjoy better quality sleep. It is the NZ brand of a patented, medically-recommended anti-snoring device that’s worn in the mouth during sleep. It works by gently repositioning the lower jaw slightly forward and this opens the airways to help minimise or even prevent snoring and from occurring.

Minimise your risk of developing dementia (as well as other issues) – discover more about ApneaRx and buy ApneaRx today.