US researchers suggests that stressful events in life such as the death of a child, divorce or being fired, can age the brain by at least four years.
The researchers looked at performance in memory and thinking tests of 1,300 people in their 50s to gauge brain health.
Although the research could not establish any direct link between stress and an increased risk of dementia, stressful experiences are known to have an impact on brain function, which could then lead to dementia in the longer term.