Researchers have found that whilst an active cognitive lifestyle cannot prevent Alzheimer's disease, it can contribute to better brain health. The scientists, whose findings will be published in next month's issue of the journal Biological Psychiatry
, found evidence to suggest that the protective effects of an active mental regime are derived from multiple biological pathways.
There has been a longstanding hypothesis that individuals with active cognitive lifestyles reduce their long-term risks of dementia.
"The ideas of a 'brain reserve' or 'cognitive reserve' have been suggested to explain this, but were basically a black box," commented Michael J Valenzuela, an Associate Professor at the University of Sydney's Brain and Mind Research Institute, who led the study. "This research throws some light on what may be happening at the biological level."
Professor Valenzuela and his colleagues examined data from a large population-based survey taken in the United Kingdom. The Cognitive Function and Ageing Study includes data taken from more than 13,000 elderly individuals since 1991. The team also had access to 329 brains that had been donated for medical research purposes. The brains were categorised depending on whether or not their owners had dementia at death, and were given a cognitive lifestyle score (CLS) of low, medium or high.
The team discovered that CLS groups did not alter in line with numerous Alzheimer's disease neuropathology measures, such as plaques, neurofibrillary tangles, and atrophy. These findings suggest that there is no correlation between cognitive lifestyle and the changes typically observed in individuals with Alzheimer's disease.
Nevertheless, the researchers did find that an active cognitive lifestyle in men was associated with lower levels of cerbrovascular disease, and in women, with greater brain weight. In both genders, individuals with a higher CLS tended to exhibit greater neuronal density and cortical thickness in the frontal lobe.
"These findings suggest that increased engagement in stimulating activities are part of a lifestyle that is, overall, more healthy," explained Dr John Krystal, Editor of Biological Pyschiatry
. "Rather than specifically protecting the health of activated circuits, it seems that a more active lifestyle has general effects on brain health reflected in greater neuronal density and preservation of the blood supply to the brain."
It is hoped that such studies could provide useful insights into the preservation of brain health; information that could prove particularly useful in relation to the globally ageing society.
"Overall, our research suggests that multiple complex brain changes may be responsible for the 'use it or lose it' effect," concluded Professor Valenzuela.