Research has shown that people who regularly stimulate and challenge their brain with complex mental activities are on average:
- more likely to have better cognitive function
- less likely to experience cognitive decline with ageing
- less likely to develop dementia
This has been found for people who are more mentally active in their youth, at middle age and also old age.
Regularly using your cognitive skills and exercising your brain builds a reserve of healthy and efficient brain cells and connections. This brain reserve may help reduce your risk of developing dementia.
What’s the evidence that mental activity reduces dementia risk?
Research consistently finds that a lower risk of developing dementia is associated with:
- higher levels of education
- more mentally demanding occupations
- participating in more intellectually stimulating leisure activities
A review of research in this area found that each of these factors was associated with a 40 – 50% reduced risk. Combining the data from 22 studies and over 29,000 participants, the researchers found a 46% reduced risk of dementia for those with high levels of mental activity (Valenzuela & Sachdev, Psychological Medicine, 2006; 36:441-454).
A second review of published research found that high levels of mental activity are also associated with reduced cognitive decline (Valenzuela & Sachdev, Psychological Medicine, 2006; 36:1065-1073).
Not everyone has the opportunity to undertake advanced education or work in mentally challenging roles. Encouragingly, cognitively stimulating activities such as listening to radio, reading, doing crosswords and visiting museums may also protect against cognitive decline and dementia.
In one study, a score of such activities ranging from 0 to 5 was developed. Each one-point increase was associated with a 47% lower risk of cognitive decline and a 33% reduced risk of Alzheimer’s disease (Wilson R, et al. JAMA, 2002; 287:742-748).
This evidence suggests that keeping your brain active and challenged throughout life may help reduce your dementia risk.
Of course, there are no guarantees. These findings represent the average for large groups of people, not the actual risk for any individual. A person who is mentally active may still develop dementia, but as a group they have less chance of doing so.
So, keep your brain active by choosing mental activities that are reasonably complex, varied, new and challenging and do them frequently. There is good evidence that this can help keep your brain functioning well and reduce your dementia risk.
Many observational studies have shown an association between lower dementia risk and keeping your brain active through learning, working and mentally stimulating leisure activities.
The association between lower dementia risk and cognitive activity has also been established in meta-analyses combining results from several studies.
Some intervention trials suggest benefits from specific cognitive training programs (e.g. computerised brain training programs), but it is still unclear whether these can reduce dementia risk.
What is lacking is proof that increasing your level of cognitive activity will reduce your dementia risk, but there are hints that it may, and it won’t do you any harm.
How does brain exercise reduce dementia risk?
We know from animal and human brain studies that learning creates new connections between brain cells. Learning new things and challenging the brain also helps develop flexible and efficient cognitive skills.
Continued learning through regular complex mental activity therefore increases “brain reserve”. There are two components of brain reserve:
- Neurological brain reserve refers to increased brain volume (more cells) and increased synapses (more connections between brain cells). This gives the brain greater physical capacity to overcome injury. It means that there is a reserve of other cells and pathways that can take over functions previously performed by damaged cells and synapses.
- Behavioural brain reserve (or cognitive reserve) refers to the ability to use flexible cognitive strategies to achieve the same outcome in a different way. This also gives the brain greater capacity to overcome injury. It means that tasks previously performed by damaged cells and synapses can be achieved using different cognitive strategies performed by undamaged brain areas.
So, if a brain is affected by a disease such as Alzheimer’s, that damages brain cells and their connections, a high brain reserve may help the brain to continue to function well. In this way brain reserve may delay the onset of dementia symptoms or make it less likely that dementia will develop.