It’s long been known that not getting enough sleep is bad for your health.
A lack of shut eye has been linked to diabetes, depression, heart disease and other troubling ailments.
And now, scientists have highlighted the impact too little sleep can have on the mind - increasing the risk of developing Alzheimer’s.
Dr Jeffrey Illif, a brain scientist at Oregon Health and Science University, told NPR that ‘changes in sleep habits may actually be setting the stage’ for dementia.
- A restless night is known to be bad for your health - leading to a variety of ailments, from depression to diabetes. But, scientists also say a lack of sleep also increases your risk of Alzheimer's disease
Sleep is beneficial for the brain, allowing for the process of clearing out toxins that trigger Alzheimer's, he said.
If a person gets too little sleep, there is a risk those toxins can build up and lead to brain damage - as seen in research in animals who do not get enough sleep.
Dr Illif and his team are about to embark on a study investigating their theory in people, which they hope will clarify the association between sleep and Alzheimer’s.
Sleep disorders are common in people with Alzheimer’s disease. ntil recently, the medical community assumed the link occurred because the disease was ‘taking out the centers of the brain that are responsible for regulating sleep', Dr Illif said.
But, recent discoveries showed the association may be more complicated than that.
A 2009 study found that the sticky amyloid plaques associated with Alzheimer’s ‘develop more quickly in the brains of sleep-deprived mice'.
And, in 2013, Dr Illif was involved in a study, which revealed too little sleep can speed up Alzheimer’s plaque development.
That study uncovered the cleansing process that takes place in the brain during sleep.
Dr Illif said: ‘The fluid that’s normally on the outside of the brain – cerebrospinal fluid – it’s a clear, clear fluid – it actually begins to recirculate back into and through the brain along the outsides of blood vessels.’
A study published this summer also found that poor sleep allows a memory-robbing protein to build up in the brain.
- Scientists found that the brain undergoes a 'cleansing' process while you sleep - clearing out Alzheimer's toxins. Without enough sleep, the toxins can build up and damage the brain and cause Alzheimer's. In turn, higher levels of this beta-amyloid protein then disrupt sleep – leading to a vicious circle that could result in Alzheimer’s disease.
If sleep is as important as believed, sleep therapies could help delay the onset of the disease, as well as slow its progression in those who already have it, experts suggest.
With previous research showing deep sleep to ‘power cleanse’ beta-amyloid from the brain, the researchers believe lack of sleep to be a key part of a vicious circle in which memory gets worse and worse.
University of California, Berkley researcher Matthew Walker said: ‘The more beta-amyloid you have in certain parts of your brain, the less deep sleep you get and, consequently, the worse your memory.
Furthermore, in October, a study from the University of California, Davis found that jet lag-style sleep problems, suffered by shift workers and frequent fliers, may cause Alzheimer's disease.
That study provided the first evidence that alterations to the body clock really can trigger the memory and learning loss symptoms that are a hallmark of dementia.