The gold standard of eight hours’ sleep is ‘WRONG’ – as scientists find sweet spot

SEVEN hours of sleep per night is the sweet spot for your brain, according to experts.

People who snooze too much or too little score lower on thinking tests, have worse mental health and face a higher dementia risk.

Cambridge University scientists checked data and brain scans from up to 500,000 Brits between the ages of 38 and 73.

While some feel fine after a short kip and others have to drag themselves out of bed in the morning, seven hours is a good rule of thumb, researchers said.

They added that a regular bedtime without late nights or early mornings is best for keeping your mind sharp.

Study author Professor Barbara Sahakian said: “Getting a good night’s sleep is important at all stages of life, but particularly as we age. 

“Finding ways to improve sleep for older people could be crucial to helping them maintain good mental health and avoiding cognitive decline.”

Prof Sahakian explained in the journal Nature Aging that deep sleep cleans the brain.

Shutting down for the night allows the body to connect and repair nerves to store memories and to clear out proteins that could otherwise build up and cause damage.

This takes hours to happen so people who don’t sleep enough miss out on the benefits.

Hormone changes mean many people find it harder to sleep through the night as they get older.

But shut-eye is vital for all ages and the NHS says all adults should get at least seven hours a night.

Professor Jianfeng Feng from Fudan University in China, a co-author on the study, said: “The reasons why older people have poorer sleep appear to be complex.

“They are influenced by a combination of our genetic makeup and the structure of our brains.

“Our analysis supports the idea that too little or too much sleep causes cognitive problems.”