Education keeps physical effects of dementia at bay, study reveals
People who go on to university or college after leaving school appear to be less affected by brain changes associated with dementia than those who cease education early, say scientists.
Yet their brains are just as likely to suffer the neurological breakdown that gives rise to the disease.
How more educated people are better able to withstand the brain damage linked to dementia remains a mystery.
Dementia, which causes memory loss and confused thinking, affects more than 800,000 mostly older people in the UK.
More than half have Alzheimer's, the most common form of the disease.
Over the past decade, research has consistently shown that the more time a person spends in education, the less he or she is likely to develop dementia symptoms.
For each additional year of education there is an estimated 11 per cent reduced risk of developing dementia.
However, until now it has not been clear whether or not education had a physical protective effect on the brain.
Alzheimer's is marked by deposits of beta-amyloid protein in the brain, and knotty protein structures in the nerves themselves called tau tangles.
Both are thought to contribute to the damage that results in the disease.
The new research involved examining the brains of 872 participants in Eclipse (Epidemiological Clinicopathological Studies in Europe), a collaboration between three large population-based studies of ageing.
Of the donors, 56 per cent were suffering from dementia when they died, the scientists reported in the journal Brain.
An association was found between more education and less risk of dementia symptoms.
But surprisingly, education appeared to have no impact on levels of dementia-associated brain damage.
Dr Hanna Keage, from Cambridge University, a member of the Anglo-Finnish team, said: "Previous research has shown that there is not a one-to-one relationship between being diagnosed with dementia during life and changes seen in the brain at death. One person may show lots of pathology in their brain while another shows very little, yet both may have had dementia.
"Our study shows education in early life appears to enable some people to cope with a lot of changes in their brain before showing dementia symptoms."
The researchers said understanding the mechanisms behind the effect would be of "considerable value to society".
Professor Carol Brayne, who led the Cambridge scientists, said: "Education is known to be good for population health and equity.
"This study provides strong support for investment in early life factors which should have an impact on society and the whole lifespan.
"This is hugely relevant to policy decisions about the importance of resource allocation between health and education."
Ruth Sutherland, chief executive of the Alzheimer's Society, said: "This is the largest study ever to confirm that hitting the books could help you fight the symptoms of dementia in later life.
"What we don't know is why a longer education is so good for you. It could be that the types of people who study longer have large brains which adapt better to changes associated with dementia.
"Another reason could be that educated people find ways of managing or hiding their symptoms.
"We now need more research to find out why an education can make the brain more 'dementia resistant'.
"Until then the message appears to be stay in school."