Having a paying job may help fend off Alzheimer's disease in women
A new study has shed light on a possible risk factor for Alzheimer's disease in women: not having a job.
Dr. Elizabeth R. Mayeda, assistant professor of epidemiology at UCLA's Fielding School of Public Health, conducted a study on later-life cognitive health in women and found that working women showed a slower decrease in memory than their non-working counterparts.
Mayeda and her team presented their findings at the Alzheimer's Association International Conference recently in Los Angeles. The study was in collaboration with researchers at the UCLA Fielding School of Public Health, the University of California, San Francisco and Boston College.
Using data from the National Institute on Aging's Health and Retirement Study, Mayeda examined the memory function patterns of more than 6,000 women born between 1935 and 1956. Women reported each year between the ages of 16 and 50 whether they were working for pay or had children, and were grouped by their work and family patterns to examine changes in memory for women over age 50.
Memory performance was measured using standardized tests about every two years, starting when the women were age 50 or older.
According to Mayeda, prior to the age of 60 there were no noticeable differences in memory between working and non-working women. However, after 60, women who participated in the paid labor force showed slower memory decline than those who didn't.
Mayeda noted that previous studies on Alzheimer's concentrated mainly on biological factors such as the presence of sex hormones like estrogen. Mayeda wanted to focus on social factors that could lead to Alzheimer's as well as late-life changes in memory function, which is considered a hallmark of developing Alzheimer's.
"When we thought about relevant social experiences that might shape risk of Alzheimer's dementia for women, we thought about how women in the United States have experienced really drastic changes in patterns of employment and family circumstances over the past century or so," Mayeda said in a recent phone interview.
According to the 2019 Alzheimer's Disease Facts and Figures report, two-thirds of people living with Alzheimer's are women and 16% of women over the age of 71 have Alzheimer's.
"The prevailing view has been that this discrepancy is due to the fact that women live longer than men on average, and older age is the greatest risk factor for Alzheimer's," the facts and figures report said.
Mayeda's findings showed that the average memory performance for non-working women between the ages of 60 and 70 declined twice as fast as women who were working. Compared with married mothers in the paid labor force, single mothers out of the workforce for long periods saw their memory faculties decline 83% faster, while married non-working mothers declined 61% faster. Memory performance for working women remained higher, even if their work history was interrupted for family reasons.
"The really striking finding is that even though we looked at work and family patterns, what really stood out in our findings was that engagement in the paid labor force was the key factor that stood out as important. We really thought that both aspects of family and also engagement in the paid labor force could both be really relevant," Mayeda said.
Dr. Tamar Gefen, an assistant professor of psychiatry and behavioral sciences at Northwestern University, said the results of Mayeda's study align with existing research on factors that lower the risk of late-life cognitive decline.
"There is evidence in the literature suggesting a limited number of factors that can perhaps lower the risk of developing cognitive impairment in later life. This includes aerobic exercise, healthy nutrition, mental activity and engagement," Gefen said in an email interview.
The study doesn't identify why working may help cognitive health for older women, but Mayeda points to social network-building, cognitive stimulation and financial independence as reasons why employment might help protect women's minds.
Mayeda said the goal in her research is to help policymakers identify strategies to improve public health on a population level. If her findings are supported by other studies, Mayeda said she looks forward to seeing policies that encourage women to join the workforce, such as equal pay, paid family leave and affordable childcare, as a way to encourage higher late-life cognitive function.
Though Mayeda and her team's research is currently unpublished, she said she'd like to examine other aspects of health in women born in later years.
"I think it would be really relevant to expand the findings, and to try to understand the explanations for these findings," Mayeda said. "Are there specific characteristics of work that are really important and relevant to women's later-life cognitive health?"
Mayeda and her fellow researchers are developing a manuscript to submit to a peer-reviewed journal.