Watching too much television has a huge impact on dementia risk, according to new research. A study from the UK Biobank project analyzed data from 407,000 adults aged 37 to 73. People who watch more than five hours of TV a day have an almost 50% greater risk of developing dementia. A high TV viewing time was also associated with higher rates of developing brain disorders like stroke and Parkinson’s disease. Researchers also found that participants who watched more than five hours of TV daily had less grey matter and smaller memory centres. Scientists believe it is the sedentary behavior, low muscle activity, and low energy expenditure of watching TV that causes these risks.