How your morning lie-in could double risk of Alzheimer’s.
Those who sleep for more than eight hours a day are twice as likely to develop Alzheimer’s, research suggests.
The danger affects both those who enjoy regular lie-ins in the morning and those who take naps in the afternoon, a study found.
The reason for the trend remains unclear. It could be that excessive sleep is an early sign of Alzheimer’s or other forms of dementia.
Staying in bed could also be a sign of depression, which is known to increase the risk of dementia in the elderly.
But it is also possible that excessive sleep actually increases the risk of developing the disease.
Researchers urged doctors to be on the look-out for long sleep as a warning that a patient is at risk.
Alzheimer’s affects an estimated 750,000 Britons and this is expected to rise as the population lives longer.
The latest research into the disease was carried out by experts at the University Hospital of Madrid in Spain.
They studied 3,286 men and women aged 65 or over.
Each one was asked about their health and lifestyle, such as how many hours of sleep they averaged over a 24-hour period, including afternoon naps.
The volunteers were then followed for more than three years, during which 140 went on to develop Alzheimer’s or another form of dementia.
The results showed those who averaged more than eight or nine hours of sleep a day were twice as likely to have developed dementia.
In a report on their findings, published in the European Journal of Neurology, the researchers said: ‘We found a significant association between long sleep duration and dementia.
‘Long sleep may be an early symptom of dementia, or could lead to an increased risk of it. But the mechanisms underlying this association are not readily explainable.’
Dr Susanne Sorensen, head of research at the Alzheimer’s Society, said: ‘This report demonstrates that sleeping longer than normal and feeling sleepy during the day is linked to getting dementia within three years.
‘There is no apparent physiological link and it is unlikely that sleeping more than normal is a direct risk factor for dementia; it may simply be an early sign of a yet undiagnosed condition. As currently only a third of people with dementia ever receive a formal diagnosis, more research is now needed to investigate these results.’
Alzheimer’s destroys chemical messengers in the brain.
It starts with the build-up of deposits called plaques and tangles which can disrupt normal messaging systems by causing inflammation.
The cause remains unknown but research suggests keeping the mind active, such as by doing quizzes, puzzles or crosswords, may help protect against this.
A study earlier this year found too much sleep is also linked to type two diabetes.
Regular lunchtime siestas increased the risk by 26 per cent, possibly by disrupting the body’s hormonal balance.
Source:Mail Online. Dated:Aug.15.2009