THE average person spends 26 years of their life asleep.
So why do we know so little about what happens while we’re snoozing, and what it can tell us about our health?
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We all understand that sleep itself is vital for our bodies and minds.
It improves concentration levels, solidifies memories, helps maintain a healthy weight, keeps the immune system strong, boosts mental health, and reduces stress, according to the NHS.
But what about the impact of what goes on in our heads during this time?
Well, scientists now say that dreaming is an indicator of a healthy brain – but having frequent bad ones, or nightmares, as you get older may mean you’re at increased risk of dementia.
Dr Abidemi Otaiku, from the University of Birmingham’s Centre for Human Brain Health, who carried out the research, said: “We’ve demonstrated for the first time that distressing dreams, or nightmares, can be linked to dementia risk and cognitive decline.
“This is important because there are few risk indicators for dementia that can be identified as early as middle age.
“While more work needs to be done to confirm these links, we believe bad dreams could be a useful way to identify individuals at high risk of developing dementia, and put in place strategies to slow down the onset of disease.”
His team studied data from three large US studies of health and ageing.
This included 600 people aged 35 to 64, who were followed for an average of nine years, and 2,600 aged 79 and older, who were followed for five years.
All participants were dementia free at the start of the study and completed questionnaires about how often they experienced bad dreams and nightmares.
This was compared with results of tests measuring their cognitive function, like their ability to recall words or count backwards at the beginning and end of the study period.
The researchers found that those who reported bad dreams and nightmares more frequently were more likely to be diagnosed with dementia in old age.
Middle-aged participants who had nightmares every week were four times more likely to experience cognitive decline over the following decade.
And those in the older group were twice as likely to be diagnosed with dementia.
The link was much stronger for men than women.
Older men who had nightmares every week were five times more likely to develop the brain-robbing disease than those reporting no bad dreams.
In women, this increase was only 41 per cent.
Lifestyle hacks to ward off dementia
While there is currently no cure for dementia, lifestyle changes can help ward off some of the symptoms.
Dr Marilyn Glenville, from Natural Health Practice, identified seven of the best.
- Diet (studies have previously shown that the Mediterranean diet – rich in fresh fruit and vegetables, olive oil and oily fish – is linked to a reduced incidence of cognitive decline)
- Vitamins and nutrients (fish oil supplements contain DHA, one of the major omega 3 fatty acids in the brain, which has been found to have a protective effect against Alzheimer’s)
- Sleep (research has shown that people who get less than five hours of sleep each night have double the risk of developing dementia)
- Exercise (an eight-year study found people who were the most active had a 30 per cent lower risk of memory and cognitive decline – and walking distance is more important than speed)
- Brain training (doing crosswords has been found to be beneficial in delaying memory decline by 2.5 years)
- Over-the-counter medicines (cold and flu, heartburn, and sleep remedies contain anticholinergics, which have been linked to brain shrinkage and poor memory performance on tests)
- Health checks (tests can look for metals such as mercury and aluminium, which can be toxic to your brain, as well as checking for nutritional deficiencies and homocysteine levels, which have been linked to a greater risk of developing Alzheimer’s)
“Overall, these results suggest frequent nightmares may be one of the earliest signs of dementia, which can precede the development of memory and thinking problems by several years or even decades – especially in men,” Dr Otaiku wrote in The Conversation.
His findings were published in The Lancet journal eClinicalMedicine, but other studies have also looked at the link between sleep and dementia and Alzheimer’s disease.
Scientists in China monitored the sleeping habits and dementia cases in 2,000 men and women over a four-year period.
They found the risk of dementia was 69 per cent higher in those who slept for more than eight hours a night compared to people who got between seven and eight hours of sleep.
The risk was also twice as high for participants who went to bed before 9pm – versus 10pm or later.
Dr Rui Liu, from the Department of Neurology at Shandong Provincial Hospital in Jinan, whose work was published in the Journal of the American Geriatric Society, said: “Our study shows that self-reported sleep problems such as long time in bed and early sleep timing are independently associated with incident dementia and Alzheimer’s in Chinese rural older adults.
“Further intervention studies may help clarify whether moderately reducing time in bed and delaying sleep timing can slow down cognitive decline and delay dementia onset in older adults.”
MORE DEMENTIA CLUES
Elsewhere, researchers have discovered that children’s dreams could predict what will happen 40 years in the future.
Scientists from the University of Birmingham found kids who regularly had bad dreams and nightmares between the ages of seven and 11 were nearly twice as likely to develop cognitive impairment – the core feature of dementia – by the time they reached 50.
They were also up to seven times more likely to be diagnosed with Parkinson’s by the same age.
These figures sound alarming. But Dr Otaiku makes clear that recurring nightmares are actually treatable and medication has been shown to decrease the build-up of abnormal proteins linked to Alzheimer’s.
He and others now hope to investigate whether nightmares in young people might be linked to a higher risk of dementia, and if how often we dream or how vivid these dreams are could also provide clues to the risk of dementia.
“The research might not only help to shed light on the relationship between dementia and dreaming, and provide new opportunities for earlier diagnoses – and possibly earlier interventions – but it may also shed new light on the nature and function of the mysterious phenomenon that we call dreaming,” he added.
Whether you’re concerned for yourself or someone you care about, it’s important to know the most common warning signs of dementia so you can ensure an early diagnosis
Alzheimer’s Society
Dementia affects more than 944,000 people in the UK, but that figure is projected to rise to 1.6million by 2040.
About two thirds are caused by Alzheimer’s, which scientists believe is caused by a build-up of toxic proteins in the brain for years or even decades before the patient becomes ill.
Dementia is the leading cause of death in Britain.
Nightmares or other sleep problems could be early warning signs, but there are many other ‘red flags’ to look out for.
According to Alzheimer’s Society, this includes:
- Memory changes (e.g. forgetting things often or struggling to retain new information)
- Difficulty doing familiar tasks (e.g. forgetting to do a typical routine task like preparing a meal or getting dressed)
- Changes in language and communication (e.g. forgetting words or using words that don’t fit into a conversation)
- Disorientation in time and place (e.g. not knowing what day of the week it is or getting lost in a familiar place)
- Impaired judgement (e.g. not recognising something that could be dangerous)
- Problems with abstract thinking (e.g. having problems understanding numbers or symbols)
- Misplacing things (e.g. putting things in places that they shouldn’t be)
- Changes in mood, personality and behaviour (e.g. becoming tearful or upset for no obvious reason)
- Loss of initiative (e.g. losing interest in friends, family and hobbies)
- Challenges understanding visual and spatial information (e.g. problems navigating new environments or placing objects on a table)
The charity says: “Whether you’re concerned for yourself or someone you care about, it’s important to know the most common warning signs of dementia so you can ensure an early diagnosis.”
