New York (Web Desk): those who pride themselves in oversleeping should consider because it might be a cause of worry.  

A recent research suggests that sleeping for more than nine hours a night could be an early warning sign of Alzheimer .

According to Scientists, those who struggle to resist the lure of a lie-in or typically rest for more than nine hours more likely to develop brain disease.

The research reveals that an inability to get out of bed may be a symptom rather than a cause of the brain changes that lead to dementia.

For this reason, simply reducing the length of sleep time is unlikely to reduce a person's risk.

American researchers found that people who consistently slept for more than nine hours each night were twice as likely to develop Alzheimer 's or other forms of dementia over the next 10 years as those sleeping nine hours or less.

Participants without a high school degree who slept for more than nine hours increased their risk six-fold, suggesting that education lessened the effect.

Lead author Dr Matthew Pase, from Boston University Medical Center, said: “Self-reported sleep duration may be a useful clinical tool to help predict persons at risk of progressing to clinical dementia within 10 years.

“Persons reporting long sleep time may warrant assessment and monitoring for problems with thinking and memory.”

Another study has found that developing rambling speech may be an early indication of mild cognitive impairment (MCI), which can lead to Alzheimer 's.

An experiment in which people were asked to create a sentence out of three words was described at the American Association for the Advancement of Science (AAAS) annual meeting in Boston.

Lead researcher Dr Janet Cohen Sherman, from Massachusetts General Hospital, said: “The MCIs are very long-winded.”

The new findings are based on data from more than 2,400 patients enrolled in the Framingham Heart Study, a major US investigation into heart disease risk factors.

Participants, who had an average age of 72, were asked how long they typically slept each night and observed over a period of 10 years.

A total of 234 cases of dementia were recorded over the follow-up period.

Sleeping for more than nine hours more than doubled the risk of both all types of dementia and specifically Alzheimer 's. It was also associated with smaller brain volume.

The article is originally published in the journal Neurology.