Regular daytime naps may be a warning sign of dementia, study claims
- Scientists claim that older people who sleep regularly are 40% more likely to suffer from Alzheimer’s disease.
- American scientists studied the daytime sleep habits of 1,400 older people under the age of 14.
- Those who slept regularly and for more than an hour in a row were most at risk.
- Alzheimer’s disease causes dementia, a disorder that robs sufferers of memory
Research suggests that regular daytime naps may be a warning sign of dementia in older adults.
Researchers have discovered what they call a “vicious cycle” between daytime sleep and memory impairment.
Scientists from Harvard University and the University of California at San Francisco have been tracking hundreds of people over the age of 80 for more than a decade.
The results showed that older people who took a nap once a day were 40% more likely to suffer from Alzheimer’s disease, the most common type of dementia.
Sleep duration was also important, as older adults who napped for more than an hour each day were also at greater risk. The researchers also found that dementia caused people to sleep longer when they developed the disorder.
Lead author Dr. Yue Leng said there is not enough evidence that daytime naps can age the brain.
“But excessive daytime sleep may be a signal of accelerated aging or the process of cognitive aging,” she said.
Researchers believe that the toxic proteins that build up in the brain due to Alzheimer’s disease affect the parts of the brain that help people stay awake.
Frequent and prolonged daytime naps could be an indicator that Alzheimer’s disease, a major cause of dementia, may be affecting parts of the brain that help us stay awake, a new study claims.
WHAT IS ALZHEIMER?
Alzheimer’s disease is a progressive degenerative brain disease in which the accumulation of abnormal proteins leads to the death of nerve cells.
This destroys the transmitters that carry messages and causes the brain to shrink.
More than 5 million people suffer from the disease in the US, where it is the sixth leading cause of death, and more than 1 million Brits have it.
WHAT’S GOING ON?
When brain cells die, the functions they provide are lost.
This 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 can live ten to 15 years.
EARLY SYMPTOMS:
- Loss of short term memory
- Disorientation
- Behavioral changes
- mood swings
- Difficulties with money or a phone call
RECENT SYMPTOMS:
- Severe memory loss, forgetting close family members, familiar objects or places
- Anxiety and frustration due to the inability to make sense of the world, which leads to aggressive behavior.
- Eventually lose the ability to walk
- May have problems with food
- Most will eventually require round-the-clock care.
Source: Alzheimer’s Association.
Dementia is one of the leading causes of death in the UK, with charities estimated that around 900,000 people in the UK and 5 million people in the US live with it.
While there is no cure yet, medications can slow its progression. But they are most effective when detected early, which makes the detection of possible signs extremely important.
The experts tracked data from 1,401 older adults with a median age of 81. Participants wore the mobility tracker for two weeks once a year, until age 14.
Any extended period of inactivity from 9:00 am to 7:00 pm was recorded as a daytime nap.
Volunteers also underwent a series of neuropsychological tests to assess cognitive function once a year.
Three-quarters of older people had no cognitive impairment, but just under a fifth had mild cognitive impairment, which is considered a precursor to dementia.
And just over 4% had Alzheimer’s when the study began.
After six years, a quarter of older people without any signs of cognitive impairment developed Alzheimer’s disease.
A comparison of daytime sleep in this group showed that daytime dreamers are more at risk of developing Alzheimer’s disease.
Dr. Leng argued that “the role of daytime sleep is important in itself and does not depend on nighttime sleep.”
Another finding from the study, published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association, is that among older adults without cognitive impairment, daily daytime sleep time increases by an average of 11 minutes per year.
However, this increase in daytime sleep doubled to 24 minutes per year after a diagnosis of mild cognitive impairment.
And that almost tripled to 68 minutes a year after being diagnosed with Alzheimer’s.
Previous research has shown that Alzheimer’s patients have fewer wake-promoting neurons in three areas of the organ.
These changes appear to be related to the abnormal accumulation of protein that occurs in the brain during disease.
She also said that future research could explore whether interrupting sleep can slow cognitive decline in older adults.
Another type of dementia, called vascular dementia, is caused by reduced blood flow to the brain.