THAT extra hour in bed in the morning could be bad for your brain.
New research has shown that those who restrict themselves to sleeping seven hours a night can prevent their brain from ageing by an extra two years, compared with those who snooze too long.
Scientists in America looked at 15,000 women in their 70s over five years and found that those who managed seven hours a night had far better concentration and memories than those who slept for nine hours.
Meanwhile, those who got less than five hours were also found to suffer.
There is already evidence that having more than seven hours of sleep a night can lead to weight gain and increase the risk of heart problems and diabetes, but the new study is one of the first to link it to concentration problems.
“The public health implications of these findings could be substantial,” said lead researcher Elizabeth Devore.
“They might lead to the eventual identification of sleep-based strategies for reducing risk of cognitive impairment and Alzheimer’s.”
A spokesman for the Alzheimer’s Society added: “A good night’s sleep is one of life’s pleasures but, once again, this robust research suggests that the quality and duration of sleep are also linked to our cognitive health.”