Early Life Employment May Reduce Memory Decline in Women

Elizabeth R. Mayeda, MD, PhD

Recently released results from a study published in Neurology suggest that participation in the paid labor force may protect against later-life memory decline. Women who worked for pay in early adulthood and midlife experienced slower rates of later-life memory decline, regardless of marital and parenthood status.

Lead author Elizabeth R. Mayeda, MD, PhD, assistant professor, UCLA School of Public Health, and colleagues collected data on women from the Health and Retirement Study (HRS), and found that between age 60 and 70 years, the average rate of memory decline was 50% greater among women whose work-family profiles did not include working for pay post-childbearing, compared with those who were working mothers.

Using linear mixed-effects models adjusted for practice effects, baseline age, race/ethnicity, birth region, childhood socioeconomic status, and educational attainment, Mayeda and her colleagues estimated associations between work-family profiles and later-life memory decline. Memory was assessed using a previously developed memory composite score combining proxy and direct memory assessments for longitudinal analysis. Each composite score was standardized to the baseline analytic sample.

Between ages 60 and 70 years, average memory score decline was 0.69 standardized units (95% CI, –0.75 to –0.63) among working married mothers. In comparison, average memory score decline was 1.25 standardized units (95% CI, –1.23 to –0.94) among non-working married mothers.

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The study featured 6189 participants, 488 of which were working non-mothers, 4326 working married mothers, 530 working single mothers, 319 non-working single mothers, and 526 non-working married mothers.

Non-working single mothers and non-working married mothers saw a similar average rate of memory score decline. Mayeda et al suggested that after age 75 years, the average rate of memory score decline was slightly faster for working single mothers compared to working married mothers, although the small number of observations made the evidence inconclusive.

Between non-working single mothers and working married mothers, there was a 0.57 standardized unit difference in average memory scores, which translated to a 2.02 risk ratio for memory impairment and a 10.2% risk difference for memory impairment assuming 10% population prevalence of memory impairment among working married mothers.

A secondary analysis that compared memory trajectories for the 3 work-family profiles that included paid labor force participation and the 2 work-family profiles that did not include paid labor force participation saw pronounced differences in average rates of memory decline. Between ages 60 and 70 years, average memory score decline was –0.44 standardized units (95% CI, –0.56 to –0.32) greater among women without paid labor force participation compared with women who participated in the paid labor force.

The mean age at baseline memory assessment was 57.2 years (range, 55.0–74.5). Additionally, the oldest mean age was among non-working married mothers while working non-mothers represented the youngest.

Over an average follow-up 12.3 years (range, 0–21.2 years), participants participated in an average of 7.0 memory assessments (range, 1–11). Working married mothers represented the longest average follow-up length and number of memory assessments, while non-working single mothers accounted for the shortest.

"Strengths of our study include the large, national cohort study design with long follow-up, life course characterization of work-family profiles, and focus on women’s social experiences. By evaluating rates of later-life decline, we were able to distinguish between pre-morbid memory function and later-life memory decline, which is more representative of accumulation of dementia-related pathology,” the study authors concluded.

REFERENCE

Mayeda ER, Mobley TM, Weiss RE, Murchland AR, Berkman LF, Sabbath EL. Association of work-family experience with mid- and late-life memory decline in US women. Neurology. Published online November 4, 2020. doi: 10.1212/WNL.0000000000010989