Another reason not to leave homework to the last minute: Pulling an all-nighter may cause brain damage, a study suggests. Researchers in Sweden studied 15 healthy men who were allowed one night of eight-hour sleep and one night of none at all, the National Monitor reports.The subjects provided blood samples before and after sleeping each night. "A night of total sleep loss was followed by increased blood concentrations of NSE and S-100B," says researcher Christian Benedict.
"These brain molecules typically rise in blood under conditions of brain damage," Benedict notes. While we're asleep, the brain clears out unhealthy materials, he tells the Daily Mail. Those substances can prompt an increase in NSE and S-100B. "Our results indicate that a lack of sleep may promote neurodegenerative processes." Scientists note that more research is needed to determine a clear link. (Read more sleep stories.)