New York: A new research has claimed that older adults who don’t get proper sleep at night are at higher risk of developing dementia. The findings showed that spending less time in REM (rapid eye movement) sleep, which is when most of our dreaming occurs — and taking longer to enter REM sleep can both raise the risk of dementia. Each percentage reduction in REM sleep was associated with a nine per cent increase in the risk of all-cause dementia and an eight per cent increase in the risk of Alzheimer’s disease dementia. Matthew Pase, a doctorate student at the Boston University School of Medicine (BUSM) in the US said,”Different stages of sleep may differentially affect key features of Alzheimer’s disease. Our findings implicate REM sleep mechanisms as predictors of dementia.” For the study, a team of researchers studied 321 participants over the age of 60. It is common for people with dementia to experience sleep disturbance. However, it is unclear if sleep disturbance occurs as a consequence of dementia or if disturbed sleep is associated with the risk of dementia in the future, the researchers said. Previous study had revealed that people who consistently sleep more than nine hours each night had double the risk of developing dementia in 10 years as compared to participants who slept for nine hours or less. Further research is needed to determine whether REM sleep helps protect the brain from dementia or is sensitive to early brain changes that accompany dementia, the researchers suggested.