Too much or not enough sleep can lead to greater cognitive decline...

 

Too much or not enough sleep can lead to greater cognitive decline... and 7.5 hours is the right amount to preserve the brain and offset Alzheimer's disease, new study shows

Because seven and a half hours is the 'sweet spot' to preserve the brain and offset Alzheimer's disease, a study shows.

Those who get too little or too much sleep experience greater cognitive decline, according to research.