Work May Give Women an Edge Against Memory Loss

When it comes to slowing memory decline, women who have been in the workforce appear to have an edge, according to a new observational study.

“In a national study, women who participated in the paid labor force between early adulthood and midlife, regardless of family structure, experienced slower memory decline in later-life than their nonworking peers, suggesting paid labor force participation plays a strong role in later-life cognitive health, ” reported Elizabeth Rose Mayeda, PhD, MPH, of the University of California, Los Angeles, and co-authors.

“These early findings suggest that policies that support paid labor force participation could be an effective population-level strategy to prevent later-life memory decline. Important areas of future research include disentangling potential mechanisms driving observed associations,” they wrote in Neurology.

In the analysis, employment, marriage, and parenthood circumstances over 12.3 years of average follow-up defined five profiles among women age 55 and older in the Health and Retirement Study. Profiles were related to memory performance on immediate and delayed recall for a 10-word list.

Comparing non-working groups (non-working single or married mothers) to women who did work for pay after childbearing (working non-mothers, working married mothers, and working single mothers), analyses adjusted for baseline age, race/ethnicity, U.S. birth region, childhood socioeconomic status, and educational attainment showed:

• Working married mothers had the highest baseline memory scores.
• Memory scores were similar across working and non-working groups between ages 55-60.
• Overall, between ages 60 and 70, average memory score decline was -0.44 standardized units greater among women who did not work compared with those who did (95% CI −0.56 to −0.32).
• Between ages 60 and 70, average memory score decline was 0.69 standardized units among working married mothers (95% CI −0.75 to −0.63) but 1.25 standardized units among non-working single mothers (95% CI −1.46 to −1.03; RR 2.0 for memory impairment) and 1.09 standardized units among non-working married mothers (95% CI −1.23 to −0.94; RR 1.94 for memory impairment).
• Average rate of memory score decline was similar for the two groups who did not engage in paid work (non-working single mothers and non-working married mothers).

In an accompanying editorial, Michelle Mielke, PhD, of the Mayo Clinic in Rochester, Minnesota, and Bryan James, PhD, of Rush University in Chicago, observed that “the entrance and expansion of women into the labor force in the mid-20th century may have provided a new avenue of cognitive reserve for women via enhanced social stimulation and cognitive engagement.

“From a lifespan perspective, the results also further highlight that factors in early adulthood and midlife can influence late-life cognitive reserve,” they wrote.

Male-female distinctions in studies of dementia risk have focused mostly on sex differences including pregnancy, the menopausal transition and use of hormone therapy, though differences in education have been studied. “Low education is associated with risk of dementia in both women and men, but women born in the 20th century have historically had less access to education than men; thus, this risk factor has had a proportionally greater impact on older women,” Mielke and James noted.

A paucity of research on gender differences in occupation or workforce participation for late-life cognitive outcomes “is particularly relevant for women because life course patterns of working, child-rearing, and marriage have changed dramatically over the last century, with an increasing number of women joining the paid labor force,” they added.

Prior work also has shown that lifetime occupational attainment and complexity are related to cognitive decline and dementia risk.

In the present study, Mayeda and colleagues included 6,189 women from the Health and Retirement Study, a national U.S. cohort representing non-institutionalized adults over age 50. They included those with one or more memory assessment between 1995 and 2015 at age 55 or older. Mean baseline age was 57.2 years; all participants were women.

The team identified work-family profile clusters based on life course patterns of employment, marriage, and child-rearing: non-working single (n=319) or married mothers (n=526); and working non-mothers (n=488), working married mothers (n=4,326), and working single mothers (n=530).

Memory composite scores were standardized to the baseline sample. Participants too impaired to complete the examination (1.7% of the total) were rated by proxy informants on a 5-item Likert scale and a questionnaire for cognitive decline (IQCODE).

Rates of memory decline were similar for married working mothers — whether they took time off work when their children were young or not — and were similar for women who were married or single.

Limitations include an observational design, precluding assignment of causality, and lack of assessment of non-marital partnerships, including same-sex marriages (which were not legal in the U.S. during the relevant time of the study). Also, full- and part-time employment was not differentiated, and volunteer work was not accounted for. Memory performance was assessed using a brief evaluation of immediate and delayed word recall with no assessment of other cognitive domains.

“It should be noted that this association can only be generalized to American women,” the editorialists observed. “This is important, considering societal and historical differences in women’s workforce participation across countries, along with some evidence that disparities in dementia risk between men and women are different in other contexts.”

1. Paid employment in early and mid-life may protect women against late-life memory decline, an observational study suggested.

2. After age 60, memory decline in non-working women was about twice that of women who worked for pay, regardless of family structure.

Paul Smyth, MD, Contributing Writer, BreakingMED™

Cat ID: 361

Topic ID: 82,361,361,192,925