7 hours’ sleep best for brain

FOR years we have been told we need eight hours of sleep a night to stay healthy and alert the next day.

But an hour less than that could be the ideal amount to keep mentally sharp and cheerful, a major study has found.

Nearly half a million middle-aged Britons were asked how much sleep they typically get over 24 hours, including naps. The results were compared with thinking skills, mental health and wellbeing.

The survey of 38 to 73-year-olds found those who got seven hours’ sleep were least likely to suffer problems such as anxiety and depression. They also did better in tests of memory, intelligence, thinking and reaction times.

Study co-author Professor Barbara Sahakian, of Cambridge University, said: ‘Many people recommend eight hours of sleep but this study has found seven hours is actually the optimal time.

‘Even if you have to work late, or stay up with a poorly child, it is important to try to get back into the rhythm of seven hours a night after that for the sake of your cognition and mental health.’