He said: ’Our research detected memory loss and brain shrinkage in middle-aged people before symptoms started to show.
So it’s important for people to find ways to reduce stress, such as getting enough sleep, engaging in moderate exercise, incorporating relaxation techniques into their daily lives, or asking their doctor about their cortisol levels and taking a cortisol-reducing medication if needed.’
He added: ’It’s important for physicians to counsel all people with higher cortisol levels.’
At the start of the study, each participant did tests on their memory and thinking skills. Then eight years later they repeated the exercises.
A subset of the group, 2,018 people, also had an MRI brain scan to measure the volume of their brain.
Once the results were adjusted for age, sex, smoking and body mass, researchers found lower scores on tests of memory and thinking in people with higher levels of cortisol than those with average levels.