It Works if You Work It: Employment Protects Cognition in Elderly

In many cultures, perhaps no more prominent than in the US, retirement – to be free of work – is considered one of life’s greatest goals. The idea is that more free time provides the leisure to do the things that a person really wants to do, such as travel, hobbies, community service, or simply taking it easy. Yet, some people seem to wither away quickly once they retire. So, would you trade freedom from work for your brain health, which is essential to experiencing and enjoying life? 

New research from Italy highlights the role of working activity in protecting cognitive health across all fragile elderly groups and individuals at very high risk for poor cognitive health. Published in the European Journal of Neurology, this longitudinal study on healthy and pathological participants maintains that, together with social connectedness, an ongoing sense of purpose, and ability to function independently, higher levels of cognitive reserve contribute to mental health and general wellbeing along the trajectories of aging.

“Many studies have been focused on the factors influencing our brain aging and differences in cognitive [health] have been often observed in association with education or other related to quality of life,” said Professor Raffaella Rumiati says, a cognitive neuroscientist at SISSA (International School for Advanced Studies) and author of the paper. “From our analysis, it emerges that the type of work activity also contributes to the differences in normal and pathological cognitive aging.”

What Do We Know About Cognitive Reserve and How to Maintain It?

Cognitive reserve, or the robustness of our brain to improvise and find alternate ways of getting a job done, has been linked to education, occupation, indices of quality of life, and physical activity. High values in these domains have been found to influence cognitive health and aging positively.

For example, education has been repeatedly associated with a lower risk of developing poor cognition and improved cognitive functioning. Certain occupations or leisure activities have been proposed to contribute to cognitive reserve and formal education. Social, mental, and physical activities have beneficial effects on cognition in the elderly and have a protective role to the brain.

But how these domains work to influence throughout life is an unanswered question. Most studies are cross-sectional, meaning that they look at data from people at one time. Cross-sectional studies do not clearly verify the change of cognitive profiles over time. Only with longitudinal studies, those that follow people throughout a time, can we really understand how factors can influence throughout life.

Italian Longitudinal Study Pins Down Factors that Affect Cognitive Reserve During Aging

This longitudinal study, carried out by a team of scientists from the University of Padua (Dip. FISPPA), SISSA (Scuola Internazionale di Studi Superiori Avanzati), and IRCSS San Camillo Hospital in Venice, looked at the effect of several factors on cognitive reserve. In particular, the researchers looked for the impact of demographic characteristics (age and sex), the presence of comorbidities, and cognitive reserve proxies (education and occupation) on a continuum from healthy to pathological aging and their persistence over time.

In the baseline study, 3018 individuals underwent a first neuropsychological assessment (T1) for suspected pathological aging. It was predicted that the younger the age and the higher the cognitive reserve proxies, the better the cognitive outcomes. In follow-up studies, 543 participants underwent a second (T2) and 125 a third (T3) neuropsychological assessment. In addition, to replicate the same pattern found in the baseline study, a slower reduction in cognitive health over time was expected in participants with higher levels of cognitive reserve.

The Italian researchers found that the higher the education, the better the performance, an effect already well known and reported in the literature. However, with this study, a new contribution is also made to the field by demonstrating the role of occupation as a good predictor of participants' performance. The younger participants, the more educated ones, and those with more complex jobs showed better cognitive performance.

While it is known that cognition is affected by aging, particularly in less educated people, the clear-cut effect of occupation found in this study points to the relevance of employment in operationalizing cognitive reserve. Unlike education, which is mostly not exclusively acquired during the first part of life, work is built on activities carried out during adulthood. It demonstrates the benefits of life-long learning mechanisms. Adult learning seems to be quite effective in preserving cognition in the elderly.

Age and education were confirmed as predictors of performance. The researchers found that education protects people potentially at risk of poor cognitive health. Still, more interestingly, these same individuals also held more complex jobs than the other two groups. Thus, it seems that less impaired individuals had cognitive reserve proxies to the highest degree.

Higher Education and Complex Education Protects Cognitive Reserve During Aging

Across assessments, the explanatory power of predictors seems progressively attenuated. In fact, as age increases, many factors affect the elderly's cognition and give rise to huge variation. Education was the only variable that continued to predict performance over time, although its effect decreased at T2 and T3.

When considering all participants, progressive reduction in cognitive reserve was found from one assessment to the next in most tests. However, when the researchers sorted the participants into those who maintained their profile or those whose profile was affected, the former showed significantly higher education and more complex occupation than the latter at both T2 and T3.

Professor Sara Mondini of the University of Padua says: "We confirmed that education protects people from the risk of [poor cognitive health] and that these individuals had held more complex occupations than the individuals of the other two groups, the subjects with mild and advanced [poor cognitive health]. Furthermore, the study showed how the group with those who maintained their cognitive profile have on average higher levels of education and more complex jobs than those from the affected group.”

In light of this research, perhaps it is worthwhile reconsidering our goals in life, what we think about retirement, and how we hope to spend our time in our later years. 

References:

Mondini S, Pucci V, Montemurro S, Rumiati RI. Protective factors for [cognition]: trajectories and changes in a longitudinal study with Italian elderly. Eur J Neurol. 2021;10.1111/ene.15183. doi:10.1111/ene.15183