Regular day time naps could be a warning sign of dementia, study claims

Regular day time naps could be a warning sign of dementia, study claims

  • Seniors who regularly nap are 40% more likely to get Alzheimer’s, a study claims
  • US scientists examined the napping habits of 1,400 seniors for up to 14 years
  • Those who napped regularly and for over an hour in a sitting were most at risk
  • Alzheimer’s causes dementia, a disorder which robs sufferers of their memories

Regular daytime napping could be a warning sign of dementia in elderly people, a study suggests.

Researchers have found what they call a ‘vicious cycle’ between afternoon snoozes and the memory-robbing disorder. 

Academics from Harvard University and the University of California, San Francisco tracked hundreds of over-80s for over a decade.

Results showed seniors who napped for at once a day were 40 per cent more likely to develop Alzheimer’s — the most common type of dementia. 

The length of shut-eye was also important, with elderly adults who snoozed for over an hour each day also more at risk. Researchers also found dementia made people nap for longer once they developed the disorder. 

Lead author Dr Yue Leng said there wasn’t enough evidence to prove napping could age the brain. 

‘But excessive daytime napping might be a signal of accelerated aging or cognitive aging process,’ she said.

Researchers believe the toxic proteins that build-up in the brain due to Alzheimer’s impact the parts of the brain that help people stay awake. 

Frequent and long daytime kips could be an indicator that Alzheimer’s disease, the leading cause of dementia, could be impacting the parts of brain that help us stay awake a new study claims


Alzheimer’s disease is a progressive, degenerative disease of the brain, in which build-up of abnormal proteins causes nerve cells to die.

This disrupts the transmitters that carry messages, and causes the brain to shrink. 

More than 5million people suffer from the disease in the US, where it is the 6th leading cause of death, and more than 1million Britons have it.


As brain cells die, the functions they provide are lost. 

That includes memory, orientation and the ability to think and reason. 

The progress of the disease is slow and gradual. 

On average, patients live five to seven years after diagnosis, but some may live for ten to 15 years.


  • Loss of short-term memory
  • Disorientation
  • Behavioral changes
  • Mood swings
  • Difficulties dealing with money or making a phone call 


  • Severe memory loss, forgetting close family members, familiar objects or places
  • Becoming anxious and frustrated over inability to make sense of the world, leading to aggressive behavior 
  • Eventually lose ability to walk
  • May have problems eating 
  • The majority will eventually need 24-hour care   

 Source: Alzheimer’s Association

Dementia is one of the leading causes of death in the UK, with charities estimating roughly 900,000 people in Britain and 5million in the US are living with it. 

While no cure exists yet, drugs can slow its progression. But they are most effective when spotted early, making detecting possible signs crucial. 

Experts tracked data from 1,401 seniors, with an average age of 81. Participants wore a mobility tracker for a two-week period once a year, for up to 14 years. 

Any prolonged period of non-activity between the hours of 9am-7pm was logged as a nap. 

Volunteers also underwent a series of neuropsychological tests to evaluate cognition once per year.

Three quarters of the seniors had no cognitive impairment, but just under a fifth had mild cognitive impairment, considered a precursor to dementia.

And just over 4 per cent had Alzheimer’s when the study began. 

After six years a quarter of the seniors without any signs of cognitive impairment had gone on to develop Alzheimer’s.

Comparing the daytime sleeping patters of this group uncovered that nappers  were more at risk of developing Alzheimer’s. 

Dr Leng argued the ‘role of daytime napping is important itself and is independent of nighttime sleep’.

Another finding of the study, published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association, was that among seniors without cognitive impairment daily daytime napping time increased by an average of 11 minutes per year. 

However, this rate of increased daily nap times doubled to 24 minutes per year after a diagnosis of mild cognitive impairment.

And it nearly tripled to 68 minutes per year after an Alzheimer’s diagnosis. 

Previous research has shown that Alzheimer’s patients have fewer wake-promoting neurons in three regions of the organ.

These changes appeared to be related to the abnormal protein build-up that occurs in the brain with the disease.  

She also said future studies could examine if interrupting naps could slow cognitive decline among seniors. 

Another type of dementia, called vascular, is triggered by reduced blood flow to the brain.