Too much sleep is bad for the brain, large-scale study shows

Excessive and insufficient sleep are similarly detrimental to your brain’s functioning, a new study has found.

The world’s largest sleep study found that people who are asleep between seven to eight hours per night performed better cognitively than those who slept less or more.

Neuroscientists from Western University’s Brain and Mind Institute released their findings on Thursday in the journal, SLEEP.

“We really wanted to capture the sleeping habits of people around the entire globe,” says Adrian Owen, Western’s researcher in cognitive neuroscience and imaging.

“Obviously, there have been many smaller sleep studies of people in laboratories but we wanted to find out what sleep is like in the real world. People who logged in gave us a lot of information about themselves.

“We had a fairly extensive questionnaire and they told us things like which medications they were on, how old they were, where they were in the world and what kind of education they’d received because these are all factors that might have contributed to some of the results.”

More than 40,000 people from around the world participated in the online study. About half of all participants reported sleeping less than 6.3 hours per night.

Conor Wild, the study’s lead author, said: “We found that the optimum amount of sleep to keep your brain performing its best is 7 to 8 hours every night and that corresponds to what the doctors will tell you need to keep your body in tip-top shape, as well.

“We also found that people that slept more than that amount were equally impaired as those who slept too little.”