Older adults who started sleeping more than nine hours a night — but had not previously slept so much — were at more than double the risk of developing dementia a decade later than those who slept nine hours or less, researchers report. 
 
 The increased risk was not seen in people who had always slept more than nine hours. 
 
 “We’re not suggesting you go wake up Grandpa. We think this might be a marker for the risk of dementia, not a cause” of the illness, said Dr. Sudha Seshadri, a professor of neurology at Boston University School of Medicine and the senior author of the study, in Neurology. 
 
 Using data from 2,457 people, average age 72, who were part of a study in Framingham, Mass., the researchers found that those with a new habit of excessive slumber were at a greater risk of all forms of dementia, including Alzheimer’s, which is characterized by a buildup of beta amyloid, a toxic protein fragment that forms plaques in the brain. 
 
 “My suspicion is that this is a compensatory mechanism: that at a time when amyloid is building up in the brain, people may be sleeping longer as the body is reacting and trying to remove it from the brain,” Dr. Seshadri added. ||||| Dr Matthew Pase, who led the research, said: “Persons reporting long sleep time may warrant assessment and monitoring for problems with thinking and memory.” 
 
 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. 
 
 Dr Rosa Sancho, from Alzheimer's Research UK, said: "While unusual sleep patterns are common for people with dementia, this study adds to existing research suggesting that changes in sleep could be apparent long before symptoms like memory loss start to show. 
 
 "Other studies have indicated a link between changes in sleep quality and the onset of dementia, and while this wasn't measured in this study, it could be an important factor affecting sleep duration.” 
 
 She added: "Understanding more about how sleep is affected by dementia could one day help doctors to identify those who are at risk of developing the condition. 
 
 Another study has found that developing rambling speech may be an early indication of mild cognitive impairment (MCI), which can lead to Alzheimer's. The new research is reported in the journal Neurology. ||||| Older men who have breathing difficulties or spend less time in deep sleep may be at greater risk of brain changes that can precede dementia, a new study suggests. 
 
 Experts said the findings don't prove that breathing disorders, including sleep apnea, lead to dementia. But they add to evidence that poor sleep may play a role in some older adults' mental decline. 
 
 Past studies have suggested that people with certain sleep disturbances may face a greater dementia risk, the researchers note. But the reasons remain unclear. 
 
 The new findings "help to explain how sleep disturbances may actually contribute to the development of cognitive impairment and dementia," said study leader Dr. Rebecca Gelber, of the VA Pacific Islands Health Care System in Honolulu. 
 
 Specifically, the researchers found that elderly men who had less oxygen circulating in their blood during sleep tended to show more "microinfarcts" in the brain. Microinfarcts are tiny abnormalities in brain tissue that can precede dementia. 
 
 Meanwhile, men who spent less time in slow-wave sleep -- the deep, restorative stage of sleep -- tended to show more atrophy in their brain tissue. 
 
 "Microinfarcts and atrophy are known to be much more common, and more severe, in people with dementia, than in people without memory problems," Gelber explained. 
 
 But this is the first study, she said, to show that certain sleep features are related to those brain changes. 
 
 However, an expert who reviewed the study urged caution in interpreting the results. 
 
 "All this shows is a linkage, not cause-and-effect," said Keith Fargo, director of scientific programs and outreach for the Alzheimer's Association in Chicago. 
 
 Fargo stressed that research into the role of sleep in dementia risk is "very important," but there are still many questions. 
 
 "What we can say is, people with sleep disturbances appear more likely to have brain changes associated with dementia," Fargo said. "There is some relationship, but researchers don't understand it yet." 
 
 The findings -- published online Dec. 10 in Neurology -- are based on brain autopsies from 167 elderly Japanese-American men who'd taken part in a long-term health study before their deaths. As part of that study, the men had their oxygen levels and brain activity monitored as they slept. 
 
 Overall, Gelber's team found, the one-quarter of men with the lowest oxygen levels during sleep were almost four times more likely to show microinfarcts in the brain, versus men with the highest oxygen levels. 
 
 Lower oxygen levels can be caused by conditions such as emphysema or sleep apnea -- where breathing stops and starts repeatedly during sleep. This study did not actually show that sleep apnea, per se, is related to brain changes, Fargo pointed out. 
 
 Gelber's team also found that study participants who'd spent less time in slow-wave sleep tended to have more brain atrophy. 
 
 "Slow-wave sleep has been considered the deep, restorative stage of sleep and is important in processing new memories," Gelber said. With age, people tend to spend less time in slow-wave sleep, the researchers say. 
 
 She added, though, that further studies are needed to see whether slow-wave sleep has a "restorative role in brain function" and whether there are ways to boost the amount of time an older person spends in that stage of sleep. 
 
 There is some evidence that treating sleep apnea can improve people's mental performance. But no one knows yet whether boosting oxygen levels during sleep actually wards off or slows down dementia, Gelber said. 
 
 Fargo agreed. He noted that people with poor sleep can have problems with memory, thinking and concentration that have nothing to do with dementia. 
 
 "If your sleep is disturbed and you're having daytime symptoms, you should see your doctor," Fargo said. "One reason is that you may find out your cognitive problems are not related to dementia at all."
– Seniors who indulge in a morning lie-in may want to take note. A new study found that older adults who slept more than nine hours a night were at double the risk of developing Alzheimer's and other neurological disorders, the New York Times reports. The red flag was limited to those who increased their sleeping time with age. But for those sleep-lovers who have always enjoyed lazy mornings curled under the covers, there was no increased risk. Senior author Dr. Sudha Seshadri of Boston University says the change in sleep patterns is likely a symptom rather than a cause of dementia. "We’re not suggesting you go wake up Grandpa," he tells the Times. In the study, researchers tracked 2,457 people over 60, average age 72, for 10 years. They write in the journal Neurology that those who began sleeping longer than nine hours had smaller brain volumes, took longer to process information, and showed signs of memory loss, reports the Telegraph. Seshadri theorizes that sleeping was a "compensatory mechanism" as the body tries to rid itself of a toxic protein called beta amyloid. A buildup of this protein in the brain causes plaques in Alzheimer's sufferers. About 7% of people over age 65 develop some form of dementia, per the Telegraph. While there is no cure, early intervention and meds can lead to treatments that can slow the onset. "Persons reporting long sleep time may warrant assessment and monitoring for problems with thinking and memory," says study researcher Dr. Matthew Pase. (Heartburn meds have been linked to a higher risk of dementia.)