Performing well at school and going on to have a complex job could lower the risk of dementia, scientists have found.
On the contrary, loneliness, watching too much TV and a sedentary lifestyle can make a person’s cognitive abilities decline more quickly, according to new research being presented to experts at the international Alzheimer's Association International Conference in Washington DC.
Researchers are also due to show attendees the results from trials Solanezumab – believed to be the first drug to halt the progression of the disease if a patient is diagnosed early enough.
One study involving 7,500 people aged 65 and above in Sweden over a 20-year period showed that dementia rates were 21 per cent higher in those whose grades were in the bottom fifth of the population. Meanwhile, participants with complex jobs involving data and numbers saw their chance of developing the disease cut by 23 per cent.
For separate study in Sweden, scientists followed the lives of 440 people aged 75 or over for nine years, and discovered that those in the bottom fifth for school grades were found to have a 50 per cent increase in the risk of developing dementia.
Mirroring the findings of the study involving 7,500 people, participants who had complex jobs involving working with people had 60 per cent lower risk of dementia. However, this was only the case for women.
Conference-goers were also shown the findings of a two-yearly assessments of more than 8,300 over 65s participating in the US Health and Retirement Study. Researchers discovered that those who lead the loneliest lives suffered a cognitive decline 20 per cent faster that those who did not.
Establishing a link between exercise and the disease, another US study of more than 3,200 adults aged 18 to 30 years over 25 years found participants who undertook only 150 minutes of medium intensity exercise per week, or watched more than four hours of TV a day, performed significantly worse in cognitive tests when they hit middle age.
Unsurprisingly, those who were both sedentary and watched too much TV were almost two times more likely to have poor cognitive function at the end of the study.
Dr Clare Walton, research manager at Alzheimer's Society, said "These studies add to a growing body of evidence which shows the number of years of education we receive, and the complexity of our jobs, may help our brains by building up a 'cognitive reserve' to help us withstand this damage.
"While more research is needed to determine why this happens, we believe that more years in education or more challenging occupations can increase the number of connections between brain cells. The more existing connections a person has, the more they could potentially afford to lose before the function of their brain is compromised by dementia.”