Although it's already known that the drugs can cause memory problems and attention, researchers from the University of Washington have discovered the drugs increase the risk of dementia and Alzheimer's disease. The risk rises with the dose and the length of time the drugs are taken.
The risks become apparent when elderly people-aged 65 years and older-have taken the drugs for longer than three years.
The researchers tracked the health of 3,434 people who had no signs of dementia at the start of the study, but were taking an anti-cholinergic drug; around 20 per cent were using an over-the-counter remedy. During the lifetime of the study, 797 of the participants developed dementia.
(Source: JAMA Internal Medicine, 2015; doi: 10.1001/jamainternmed.2014.7663)