- Seven-and-a-half hour ‘sweet spot’ is there to protect the brain and ward off Alzheimer’s
- People who get too little or too much sleep experience greater cognitive decline
- 100 older adults in the study slept with monitors tied to their foreheads most nights
If you’re in the habit of trying to get eight hours of sleep a night, you can start setting your alarm 30 minutes earlier.
Because seven and a half hours is the ‘sweet spot’ for preserving the brain and staving off Alzheimer’s disease, a study suggests.
According to research, people who get too little or too much sleep experience greater cognitive decline.
One study suggests that seven and a half hours of ‘sweet spot’ is the key to preserving the brain and warding off Alzheimer’s disease. (stock image)
Dr Brendan Lucy, associate professor of neurology at the Washington University Sleep Medicine Center, said: ‘Our study suggests that there is a moderate range, or ‘sweet spot’, for total sleep time, where cognitive performance was stable over time.
‘Short and long sleep times were associated with poorer cognitive performance, probably due to insufficient sleep or poor sleep quality.’
In the study, published in the journal Brain, 100 older adults, with an average age of 75, slept with a small monitor on their forehead to measure brain activity during sleep for an average of four and a half years.
In a study conducted by the Washington University Sleep Medicine Center, 100 older adults with an average age of 75 slept with small monitors on their foreheads on most nights. (stock image)
The scientists also took cerebrospinal fluid, found within the tissue surrounding the brain and spinal cord, to measure levels of the Alzheimer’s protein.
Cognitive scores declined for the groups that slept less than five-and-a-half hours or the equivalent of more than seven-and-a-half hours per night.
Previous research has found that memory loss, confusion and slow learning of new things, all symptoms of Alzheimer’s, are associated with poor sleep.