Research from the University of New South Wales (UNSW), Australia, provides the most convincing evidence to date that complex mental activity across people's lives significantly reduces the risk of dementia. The researchers found that such activity almost halves the incidence of dementia.
The paper, which has just been published in Psychological Medicine, is the first comprehensive review of the research in the field of 'brain reserve', which looks at the role of education, occupational complexity and mentally stimulating lifestyle pursuits in preventing cognitive decline. The paper integrates data from 29,000 individuals across 22 studies from around the world.
"Until now there have been mixed messages about the role of education, occupation, IQ and mentally stimulating leisure activities, in preventing cognitive decline. Now the results are much clearer," said the lead author, Dr Michael Valenzuela, from the School of Psychiatry at UNSW. "It is a case of 'use it or lose it'. If you increase your brain reserve over your lifetime, you lessen the risk of Alzheimer's and other neurodegenerative diseases."
The key conclusion is that individuals with high brain reserve have a 46 percent decreased risk of dementia, compared to those with low brain reserve. All the studies assessed agreed that mentally stimulating leisure activities, even in late life, are associated with a protective effect.
"This suggests that brain reserve is not a static property, nor that it is determined by early life experiences such as level of education, socio-economic deprivation or poor nutrition," said Dr Valenzuela. "It is never too late to build brain reserve."