Young adults who watched a lot of TV but did little exercise were found to have noticeably worse cognitive function 25 years later. A team from the Northern California Institute for Research and Education studied 3,247 adults aged 18 to 30 over a quarter of a century. Participants completed regular questionaires logging hours of TV viewed and levels of physical activity.
At the end of the study cognitive function was evaluated in three tests assessing processing speed, executive function “ which controls a range of mental skills “ and verbal memory. Individuals with both low physical activity and high sedentary behaviour may represent a critical target group.
Almost 11 per cent of those who took part watched more than three hours TV a day and were more likely to have poor cognitive performance. Low physical activity was witnessed in 16.3 per cent and was associated with poor performance on one test.
Poor cognitive performance was almost twice as likely in adults with both high viewing levels and low physical activity.
Lead researcher Dr Tina Hoang said: “Low activity and high viewing were associated with slower processing speed and worse executive function but not with verbal memory. “Individuals with both low physical activity and high sedentary behaviour may represent a critical target group.”
The study has been published online by JAMA Psychiatry.
