Kaiser Permanente research examines how occupational complexity relates to late-life cognitive function
As the number of older adults experiencing dementia grows with an aging U.S. population, researchers are working to understand what factors throughout life may contribute to late-life cognitive health. A new study from Kaiser Permanente Division of Research investigators suggests one factor may be how intellectually challenging a person’s job is.
The research was led by Yenee Soh, ScD, a DOR research fellow, and DOR investigator Paola Gilsanz, ScD. The findings were published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
The authors discussed their findings and what comes next.
What do we know so far about using our brains to keep them healthy?
Soh: A lot of research suggests that intellectually stimulating activities throughout adulthood are associated with better cognitive outcomes, and complex work environments have been examined as one source of such intellectually stimulating activities. Several studies have shown us that more occupational complexity provided by one’s occupation is associated with better late life cognition. Very few have looked at these associations in a racially and ethnically diverse population.
How did Kaiser Permanente data give you a unique view on this topic?
Gilsanz: We used data from the Kaiser Healthy Aging and Diverse Life Experiences study, also known as KHANDLE. The participants are a diverse group of long-term members of Kaiser Permanente Northern California ages 65 and older. To be eligible, Kaiser members had to have participated in at least one voluntary checkup between 1964 and 1985 that included a health questionnaire and clinical measures. This is really exciting because we are able to look at data from earlier in their lifetime along with the information they provided about life experience and health indicators during KHANDLE interviews.
How do you measure occupational complexity?
Soh: KHANDLE participants provided information on their main lifetime occupation, and using federal job classifications, each participant’s job was linked to 3 dimensions of work complexity: complexity with data, complexity with people, and complexity with things. We then examined how each measure of occupational complexity was associated with three domains of cognition: executive function, semantic memory, and verbal episodic memory.
What did you learn?
Soh: We found that higher occupational complexity with data was associated with higher baseline executive function and semantic memory, as well as slower decline for executive function. We also found that higher occupational complexity with people was associated with higher baseline cognition across all domains. We didn’t find that the connections between occupational complexity and cognition varied by race.
But we did find differences in levels of occupational complexity in the jobs reported by race and ethnicity, which reflects how structural racism impacts job opportunities and opportunities for cognitively stimulating work environments.
So does this study mean that younger people should get intellectually challenging jobs to avoid dementia?
Soh: These results suggest that more intellectually challenging jobs are linked with cognitive benefits. However, we still do not know the pathways underlying how occupational complexity affects cognitive abilities. More research will help translate these findings into workplace interventions or occupation-related decisions for cognitive health.
What needs to be studied next on this topic?
Soh: There are a multitude of work characteristics and environmental factors that need to be considered to better understand the occupation-cognition relationship. These may include occupational prestige, job hazards, or work stress. Future research should look at how these factors in conjunction may be related to risk of late life cognitive outcomes.
Gilsanz: Understanding the mechanisms through which occupations and jobs affect healthy brain aging is really valuable, especially if we identify things that we can change. That way you can intervene and hopefully improve healthy brain aging for everyone.
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About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 600-plus staff is working on more than 450 epidemiological and health services research projects. For more information, visit divisionofresearch.kaiserpermanente.org or follow us @KPDOR.