Waking up to sleep as a risk factor for dementia

Looking at the association between dementia and sleep, considering if sleep is a risk factor of dementia.

We know that we can promote brain health with physical exercise and our diet, along with not getting obese, not smoking and drinking alcohol only in moderation. But how many of us would put a good night’s sleep on this list? We’re slowly waking up to the idea that maybe we should.

dementia and sleep

In this blog I summarise some of the current thinking on sleep as a risk factor for dementia and touch on how to get a good night’s sleep, with a focus on healthy over-50s. (I don’t cover links between sleep and other aspects of health, which are huge.) In a later blog I’ll look at sleep and related issues like sundowning in people who are already living with dementia.

Sleep is active, not passive

Sleep is not just something passive that we do when we’re tired. It’s a vital, active and purposeful phase of our lives. Exactly what sleep is ‘for’ is hard to define, though researchers agree that one clear purpose is to repair cells and tissues.

Sleep is also important for making long-term memories. During sleep, memories for events are transferred out of short-term storage in the hippocampus and into the long-term storage of the cortex. (For more about these parts of the brain and ‘consolidation’ of episodic memories, see our webpage Dementia and the brain.) Studies of the brain’s electrical activity while we sleep show that memory consolidation happens mainly during certain phases of deep sleep, notably ‘slow wave sleep’.

So might poor sleep have an impact on our memories, especially as we age?

Sleep quality

It’s worth defining ‘poor’ sleep here. For some people poor sleep means trouble getting to sleep; others will drop off easily but then find themselves wide awake at 3am. Some people have a ‘fragmented’ sleep pattern in which they sleep fitfully and don’t feel rested.

The consensus is that averaging seven to eight hours a day is enough for adults. People who don’t sleep well at night often find themselves feeling very tired (and so napping) during the day. In some people what started as a short nap becomes excessive daytime sleepiness.

What are the risks of poor quality sleep?

dementia and sleep

Our own experience tells us that if we have a bad night’s sleep we tend to be less sharp the day after. Research supports this, with poorer sleep linked to worse ‘executive function’ (including decision-making, planning, judgement), memory and attention next day.

We should not worry overly about an occasional bad night, but does regular poor sleep cause long-term harm? Some large studies do show that regularly sleeping for less than 5 hours in middle age (say age 40-60) is linked to later cognitive decline, including mild cognitive impairment and Alzheimer’s disease.

The ‘linked to’ here matters: this is an association, not a proven cause and effect. And ‘middle age’ matters too, because these relationships don’t hold for older adults, over 60. (This kind of relationship between age of exposure and dementia risk is also seen for some other risk factors, including high blood pressure and depression.)

That disturbed sleep might raise our risk of dementia is now supported by a different kind of evidence looking at beta-amyloid.

The clumping of beta-amyloid within the brain into plaques, starting well before any symptoms of dementia, is thought to be central to the development of Alzheimer’s disease. Research on mice now suggests that amyloid levels rise during wakefulness but fall again as amyloid is cleared during sleep.

The suggestion then is that amyloid clearance from the brain is reduced if there is poor quality sleep, and that this is one way that disturbed sleep may be linked to a higher risk of subsequent Alzheimer’s disease. Whether this actually happens in humans is not yet clear, and it wouldn’t explain links with other dementias, in which amyloid is not implicated. But it is an area to watch.

What can I do to sleep better?

So sleep really matters. What can we all do to sleep better? A recent report from the Global Council on Brain Health lists recommendations for a range of different groups. Here are a few headlines, but read their report for the full list.

‘Sleep hygiene’ advice to promote sleep in healthy over-50s includes:

  • Get physical exercise during the day, and exposure to natural light.
  • Avoid caffeine after lunch – it’s found in tea, cocoa and cola as well as coffee.
  • Don’t eat or drink lots before bed – alcohol in particular may make you sleep but then wake up when its effects wear off. Smoking before bedtime is also not a good idea.
  • If you must nap during the day, keep it to at most 30 minutes in the early afternoon.
  • Have a regular routine with set times for going to bed and getting up
  • Don’t stay in bed if you’re not sleepy or have had enough sleep
  • Keep the bedroom quiet and dark at night and at a good temperature
  • Don’t have a TV, smartphone or tablet in the bedroom.

If these recommendations don’t work and you regularly have poor sleep, it is worth seeking medical advice. Regularly disturbed sleep is not a normal part of healthy ageing. Your doctor should take poor sleep seriously. They should check to see if any sleep problem is a side-effect of medication (including over-the-counter drugs) or is a symptom of a condition such as depression or sleep apnoea, or of the menopause in women.

Non-drugs approaches can sometimes help with poor sleep. They include cognitive behaviour therapy for insomnia, and relaxation or deep breathing exercises.

It’s tempting but mistaken to look to medication as a quick fix. If medication is offered, a ‘Z’-drug like zopiclone is likely to be preferred these days over a benzodiazepine like diazepam. Drugs based on melatonin, made naturally when we’re exposed to sunlight, are also coming on stream. But all drugs over-medicalise a problem for which more effective measures, including those listed above, already exist. They should not be the first choice and even if taken this should only be intermittently. 

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I FOUND THIS TO BE A VERY INTERESTING ARTICLE. I HAVE NOT HAD A DECENT NIGHTS SLEEP FOR NEARLY 5 YEARS. IT ALL STARTED WITH ME LOSING MY JOB AFTER BEING CONTINUOUSLY EMPLOYED FOR 35 YEARS.THEN DUE TO FAMILY COMMITMENTS, I FOUND THAT I HAVE VERY LITTLE TIME TO MYSELF TO DO THINGS THAT I WANT TO DO.I ALWAYS SEEM TO BE IN A POSITION WHERE I HAVE TO PUT THE NEEDS OF OTHERS ABOVE MY OWN.IT IS A QUESTION OF PRIORITIES.MY LIFE IS ON THE BACKBURNER AS THEY SAY. I COPE WITH DAY TO DAY CHALLENGES THE BEST WAY I CAN IN WHATEVER SITUATION I FIND MYSELF IN. THEN WHEN I GO TO BED I AM UNABLE TO GET A DECENT NIGHTS SLEEP BECAUSE I AM UNABLE TO SWITCH OFF AND PUT THE DAYS EVENTS OUT OF MY MIND.I JUST LAY THERE WORRYING ABOUT WHAT IS GOING TO HAPPEN THE FOLLOWING DAY. I NEED TO GET ANOTHER JOB AND START TO EARN A REGULAR INCOME AGAIN, BUT DUE TO MORE IMPORTANT COMMITMENTS I AM UNABLE TO DO THIS. SOMEDAYS I FEEL THAT I AM WHIZZING AROUND ON A TREADMILL THAT IS GOING FASTER AND FASTER AND I AM UNABLE TO GET OFF IT AND SLOW DOWN

Don't put your life on the "backburner"- you don't get a second chance at it! Same goes for your health. It is easy to say but we get into positions where our needs are second best, but we allow that to happen. Your health and wellbeing is just as imprtant as these family commitments you speak of, I think you should seek professional help as it feels to me that you are heading towards burn-out!

HELLO SUE,THANKYOU FOR ANSWERING,I AM NOT SURE IF I NEED PROFESSIONAL HELP OR WHAT THE ANSWER IS. I DO NOT KNOW HOW OTHER PEOPLE COPE WHO ARE IN THE SAME POSITION AS ME OR IF I AM DOING THINGS THE RIGHT WAY.AS I SAY MOST OF MY TIME IS OCCUPIED BY DOING THINGS THAT ARE DONE OUT OF A SENSE OF DUTY BECAUSE IT IS NECCESARY AND IS MORE IMPORTANT THAN OTHER THINGS

Hi Colin, I’m glad you liked the article and am sorry to hear about how you feel. I know a lot of people will recognise that ‘treadmill’. We can’t give individualised advice by blog, but for someone struggling with those kinds of difficulties we would often suggest a lot of the advice in the article, like physical exercise, talking to others and good ‘sleep hygiene’. It may help to write down your worries before bed as a way to put them aside til morning. Some people use mindfulness, breathing exercises or relaxing music to de-stress and switch off. We would also say it’s OK to be a bit ‘selfish’ and look after yourself more – this will make you better able to help the others you mention. If you’re still struggling, do talk to the doctor about being referred to someone to speak to, such as a counsellor. If you’re caring for someone with dementia, call our Helpline: 0300 222 11 22

I'm not surprised you're not getting enough sleep as you have so much on your mind that unfortunately we were not given switches to turn our minds off! My sleep also is very sporadic. Often up for calls of nature a couple of times in the night. Partner that snores very loudly! (I now sleep on the sofa). Teenage son bouncing about at 3am on his PS4!
Dog randomly barking at the sound (or smell?!) of foxes prowling around. Recent death of my mother who had dementia for 6 years and who I cared for as best I could as I couldn't bear the thought of her going into a home. Have tried sleeping tablets in the past but if you read the list of side effects that's enough to keep you awake worrying!! I remember reading a side effect from the sleeping tablet was depression and a side effect from an anti-depressant was insomnia!! LOL! I could go on and on. So my advice is try not to worry about your lack of sleep. I don't any more. If I'm tired I don't drive. And I am fortunate that I don't work so have the occasional nap in the afternoon. Good luck

Fair enough, insufficient sleep is harmful, but there isn't much point in telling me that now, because I'm 72 and I already have Alzheimer's!

However, that's only a silly niggle. There is a much bigger problem with your argument.

The true cause of our lack of sleep is that we no longer need it - because we're not physically tired - and we can stay active all night because we have (in effect) abolished darkness.

We were wild animals, designed by nature to live in rhythm with the sun. But then we invented electric light, the train, the car, the comfy chair, the book, the TV and the pint of lager. Now I stay up late because I can. Neither my body nor my brain is tired. Sleep just gets in the way of more interesting tasks, like watching Man City versus Leicester or writing to the Alzheimer's Society.

The real answer to this problem - and it is a really big problem of modern life - lies in recognising why it exists, and finding a solution that is based on modern realities. This will be difficult. We have learned to enjoy idleness and our consequent ability almost to ignore sleep and we have come to think of these things as rights. We won't fix the problem until its root causes are recognised and addressed in medicine, policy and the law.

In particular, we must reduce our dependence on wheels and chairs and reinstate day and night, for which human beings are designed and without which we cannot thrive.

You’re right Martin when you suggest that we’ve come to regard sleep as an ‘optional extra’. We could probably all benefit from less time on the screen and more time out in the real world, getting exercise, meeting people and keeping the mind active. (I can’t comment on Leicester City I’m afraid, but do keep in touch with Alzheimer’s Society.)

Both my parents had dementia and my father was an insomniac.I have long suspected that their snoring was a factor in the development of the disease.I did not realise that my mother had sleep apnoea until I shared a room with her and by then it was too late as she would not have worn an oxygen mask. I would urge anyone with a problem with snoring to get checked out by their g.p.

Thanks Jeanette for your comment. We don’t know for sure that sleep apnoea is a risk factor for dementia, but there is some evidence that it is. It’s always worth getting these physical conditions checked out by a doctor as treatments are available.

Thank you for this article on sleep. It explains a lot to me and very informative. As a carer, I don't get much sleep, and I worry about the impact the lack of sleep might have on the possibility of me developing a form of dementia. As my husband has been diagnosed with Dementia, I now wonder whether his working life style previously(working alternate nights and days) might explain his diagnosis. I have also been trying to impress on my children how important it is to get at least 8 hours sleep, maybe not less than 6 hours. Obviously, my husbands sleep pattern before and now after diagnosis has been detrimental to his condition. But I am going to try and get at least the 6 hours at a minimum. Thank you

HELLO MARIE I AM ALSO A CARER AND I AGREE WITH WHAT YOU HAVE SAID ABOUT NOT GETTING ENOUGH SLEEP.YOU CANNOT SLEEP BECAUSE YOU ARE CONSTANTLY DISTURBED DURING THE NIGHT TO LOOK AFTER THE NEEDS OF THE PERSON YOU ARE CARING FOR.AS A RESULT YOU ARE ALL DAY IN A STATE OF CONSTANT EXHAUSTION. I AM SO TIRED SOMETIMES THAT I FIND IT DIFFICULT TO FUNCTION PROPERLY TO CARRY OUT THE SIMPLEST OF EVERYDAY TASKS.I DO NOT KNOW ABOUT YOU BUT I HAVE FOUND THAT YOU DO NOT HAVE ADEQUATE TIME SOMEDAYS TO DO THINGS THAT YOU WANT TO DO. THE PERSON YOU ARE CARING FOR MUST ALWAYS COME FIRST AND THIS IS HOW IT SHOULD BE.I TRY TO LOOK AFTER MY OWN HEALTH AND WELL BEING AS WELL BUT IT IS A CASE OF PRIORITIES LIKE EVERYTHING ELSE IN LIFE. LOOK AFTER YOURSELF BEST WISHES COLIN

Very interesting article. My husband has dementia (we have never been told what type) but he has always been a very good sleeper nothing seems to keep him awake. He sleeps a lot during the day as well. I am the one who does not sleep well. I have always been like this. I work hard during the day looking after my husband. I do not get any help.

hello , you need to get some help as I had to do or else you will work your self into the ground.i have found that no one will help you in this life unless you ask for it. I am a carer also and I do not sleep well.it is easy to worry yourself into an early grave if you are not careful

My mum hasn't slept properly for years, she is worse that ever now. Constantly tired and feels she doesn't get a deep sleep, when she does sleep, she just has dreams, usually awful ones. Her memory is worse, it is very noticeable now. I am very worried! She's tried tablets from the doctor to try and sleep, they haven't worked. Also a homeopath as I thought there may be some issues on her mind that she needs help letting go of. I thought it might help her stop worrying and thinking too much while she's laid trying to sleep. She often has days where she jus doesn't feel with it and can't focus on anything or think. I'm so worried and want to try and see if there is anything out there that can help. She's not been diagnosed with dementia but worryingly these look like early signs. Also she just needs to sleep, she is always tired. Feeling like a half hour nap in the afternoon, but it doesn't really help. She's aware of the link between lack of sleep and dementia and wants to find help.

Dear Kate
I’m sorry to hear about your mum. It might be worth trying some on the non-drug approaches mentioned above if the tablets from the doctor have not worked. We can’t offer medical advice but it is possible she is depressed, stressed or anxious, all of which can cause sleep problems. For these, and if you are worried about noticeable decline in memory, we would always recommend seeing the GP. He or she should be able to find the underlying cause and then you will know and be able to move on. There is a summary of assessment for suspected dementia here if you are interested, but I would stress this is only one possible outcome – the main thing is to seek medical advice.

HELLO KATE MY MUM WAS DIAGNOSED WITH VASCULAR DEMENTIA IN 2013 AND SHE HAS NOT SLEPT PROPERLY SINCE. I AM HER SON AND CARER AND IT IS A FULL TIME JOB AND VERY TIRING.BECAUSE SOMETIMES SHE SLEEPS A LOT DURING THE DAY, SHE DOES NOT SLEEP AT NIGHT AND SOME NIGHTS SHE IS UP AN DOWN ALL NIGHT. YOU NEED TO GET YOUR MUM CHECKED BY A DOCTOR TO SEE IF SHE HAS GOT THE EARLY ONSET OF DEMENTIA.I FIND THAT AS A CARER YOU ARE VERY MUCH ALONE AS THERE IS VERY LITTLE SUPPORT FROM THE DOCTORS AN EVEN SOME MEMBERS OF YOUR FAMILY ARE NOT INTERESTED IN HELPING.THEY WOULD RATHER BURY THEIR HEAD IN THE SAND,LOOKTHE OTHER WAY AND WALK AWAY FROM IT. THIS JUST MAKES IT MORE DIFFICULT FOR YOU AS THERE IS MORE WORKLOAD PUT ON YOUR SHOULDERS.BEST WISHES COLIN

This article interests me because as a clinical hypnotherapist I see sleep as one of the vital areas for improvement in most of my clients, regardless of their reasons for coming to see me in the first place. Once we see the quality and quantity of sleep improving, clients begin to regain control of their lives; stress is reduced, memory improves, along with decision making and clarity of thought.

Those with stressful lives certainly need support to find time for themselves to really relax and reset the sleep clock. Self care is very far from being selfish - in fact it's vital.

I now have Alzheimer's (aged 73) and my father got vascular dementia at around the same age. You could say that neither of us got 'enough' sleep for the same reason: sleep is dull!

Both of us intensely enjoyed (and I still enjoy) interesting projects of various kinds, and when I was a teenager I learned from Dad to carry on working half the night. Since we also had to be at work at 7.30am for many years, we probably averaged no more than 4 or 5 hours per night. It is a very hard habit to break. I still annoy my partner by staying up until 1 or 2am, though I don't usually get up before 8am these days. I just keep forgetting the time.

By the way, I did try mindfulness, but I reckon it relies on a person believing it will work, and I can't convince myself of that.

Martin C

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