The fight against dementia: the role of the brain’s resilience

The fight against dementia: the role of the brain’s resilience

Amongst the chronic conditions that threaten the independence or successful ageing, dementia is positioned as one of the most significant health care challenges of older life. Family members of individuals diagnosed with dementia often worry about inheriting the disease themselves, or passing it on to their children. However, recent research has explored the interaction between genetic variations, environmental conditions, and lifestyle factors, leading to the consensus that one in three dementia cases can be prevented through healthy lifestyles.

On one hand, some of the behaviours that have been identified as reducing dementia risk (e.g. decreasing hypertension, obesity and smoking) benefit the heart and circulatory system, and as a rule of thumb, anything that is good for the heart, is good for the brain. On the other hand, other behaviours, such as increasing education and complex occupations, build the brain’s natural resilience or cognitive reserve. By increasing cognitive reserve capacity, the brain can resist the neurological damage associated with ageing and retain function through reorganisation and adaptation, actively compensating by engaging efficient networks.

Research looking into brain resilience has concluded that cognitive capacity varies between people. There is evidence suggesting that the knowledge and experiences individuals acquire through their lifespan help to explain differences between people’s ability to tolerate brain damage. Most research on activities that contribute to an increased cognitive reserve has pointed at the beneficial long-term effects of educational attainment, occupational training, and complexity, a socially engaged lifestyle, and cognitively effortful recreational activities.

In line with the current understanding of cognitive reserve and dementia prevention, a new study carried out at UCL Department of Behavioural Science and Health found that higher cognitive reserve was significantly associated with a reduced risk of developing dementia over a 15-year follow-up period in a nationally representative sample of English adults aged 50 years and older. For this study, cognitive reserve was measured as a combined score of educational attainment, occupational complexity, and engagement in 15 different leisure activities. The range of leisure activities was reflected by various activities such as reading the newspaper, engaging in hobbies or pastimes, participating in various types of social activities such as taking journeys with friends and family and even fixed activities such as pet care.

The study found a 35% reduced risk of dementia for participants who had increased levels of cognitive reserve, compared to those with low levels. The study also found an independent association for each cognitive reserve marker with a reduced risk of developing dementia. When compared to participants with few years of education, individuals with 15 years of education and under the age of 80, showed a 44% reduced risk of developing dementia, but this association was not significant for the older participants who perhaps had lower access to education during and immediately after the Second World War. Complex occupations showed a 28% reduced risk of dementia compared to those with less complex occupations. Lastly, a higher engagement in leisure activities showed a 26% reduced risk of developing dementia for individuals under the age of 85 when compared to individuals with lower engagement in the same age group.

The evidence confirms that education and complex occupations help develop cognitive reserve from a young age and during adulthood. Still, it is important to remember that these are not the only activities that can benefit the brain. This study ascertained engagement in leisure activities from age 50 onwards, showing a contribution of these activities to cognitive reserve during adulthood and older age. The findings also support the theory that cognitive reserve can be improved all through the life-course by engaging in a wide array of leisure activities from solitary nonstrenuous activities, like reading the newspaper and using new technologies, to active participation in clubs, societies, and volunteering programs.

The findings of this study support the current consideration that dementia prevention is at everyone’s reach, provided they live under the appropriate social and environmental conditions and have access to cognitively stimulating activities. Hence, this evidence should be implemented into interventions providing opportunities for stimulating mental and social activities for individuals who might not have benefited from access to education and other important determinants of cognitive reserve throughout their lives

Reference:
Almeida-Meza, P., Steptoe, A., & Cadar, D. (2020). Markers of cognitive reserve and dementia incidence in the English Longitudinal Study of Ageing. The British Journal of Psychiatry, 1-9.

 

Pamela Almeida-Meza is an Alzheimer’s Society funded PhD student in the Department of Behavioural Science and Health at UCL. Andrew Steptoe is the director of the English Longitudinal Study of Ageing and the Head of the Research Department of Behavioural Science and Health at UCL. Dorina Cadar is Senior Research Associate in the Department of Behavioural Science and Health at UCL.

Image: Stux, Pixabay

1 Comment responses

  1. Avatar
    May 06, 2020

    Excellent study and very informative. You could say that it is the much delayed counterpart to Bernstein’s old thesis of restricted and elaborated codes or just the old saw of ‘use it or lose it.’ What it importantly suggests is that life long learning really matters. What I would like to see now is how physical activity, membership of networks and nutrition also plays a role.

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