As global populations and life expectancy continue to rise, there is increasing concern about the occurrence of neurodegenerative diseases (such as Alzheimer’s disease, dementia, etc.). For most of these diseases, there is no cure, and so it is key to understand what affects and influences cognitive function over an individual’s lifetime, with a specific focus on modifiable risk factors.
Growing evidence shows that cognitive engagement is linked with better cognitive function, implying that continued participation in the labour force (working/having a job) may be protective against cognitive decline. A recent study carried out by scientists in Germany investigated this area of research and the cognitive effect of postponing retirement age to 67.
Because most research tends to focus exclusively on single, independent factors, like education or ethnicity, and don’t account for how life-course factors are dynamically interconnected, most research trying to identify and quantify the effect of retirement on cognitive decline have proved ambiguous. However, the study in question approaches retirement and cognitive function from the realistic perspective that they both come near the end of a long path of life. The study also takes into account the wide variety of factors that accumulate and interact over a lifespan to affect both cognitive function and age at retirement.
The researchers used data from the Health and Retirement Study (HRS). HRS (started in 1992) is an ongoing nationally-representative study of American residents aged 50 and above, and their spouses regardless of age. It holds retrospective data on early-life environment and educational attainment, cognitive function, health and health behaviours, and labour force participation. The researchers used data from HRS on over 20,000 Americans aged 55 to 75 who participated in the labour market at some point between 1996 and 2014.
The results showed that there is a positive effect for both men and women of postponing retirement until age 67 or older, with a 30-34% reduction, for men and women respectively, in cognitive decline. Certain analyses were carried out to maintain accuracy and reliability and, in these cases, any effect at age 67 or older is evidence of a lasting protective effect of postponing retirement. In most scenarios, the protective effect continues at least five years after retirement, up to at least age 72 for both men and women. This protective effect doesn’t work because participation in the labour force improves cognitive function, but rather because those who retire younger than 67 experience faster cognitive decline; so the effect is due to a slowed rate of cognitive decline as opposed to an increase in cognitive function. Furthermore, the effect seems to hold regardless of gender, education, or occupation. This is strong evidence that postponed retirement is associated with better cognitive function. Working until the age of 67 slows cognitive decline and seems to be neuroprotective, specifically against cognitive impairment and dementia.
The clear implication is that more recent groups, who have an older legal retirement age, may, in fact, enjoy a continuing protective effect of postponed retirement against cognitive decline. By using advanced models that better reflect the practical reality of interconnected factors and processes during one’s lifetime, the work of this research advances our understanding of how retirement affects cognitive function.
Original Paper: Hale, JM., Bijlsma, JM., and Lorenti, A. (2021) “Does postponing retirement affect cognitive function? A counterfactual experiment to disentangle life course risk factors.” Science Direct.
Original Link: https://doi.org/10.1016/j.ssmph.2021.100855
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Edited by: Sophie