A recent study led by Molly Fox, an anthropology professor at UCLA, suggests that pregnancy and breastfeeding are linked to improved long-term cognitive function in postmenopausal women. The research, published in Alzheimer’s & Dementia, analyzed data from more than 7,000 women aged around 70 who participated in the Women’s Health Initiative Memory Study and the Women’s Health Initiative Study of Cognitive Aging. These studies tracked participants for up to 13 years.
The researchers found that both the cumulative time spent pregnant and the time spent breastfeeding were associated with higher scores in cognition, verbal memory, and visual memory later in life. According to their findings, each additional month of pregnancy or breastfeeding was linked to a slight increase in overall cognitive ability. For example, women who had been pregnant for an average of 30.5 months had a 0.31% higher global cognition score compared to those who had never been pregnant. Similarly, those who breastfed for an average of 11.6 months had a 0.12% higher global cognition score if all other factors were equal.
“Any ways in which we can focus public health outreach or clinical interventions toward higher-risk populations leads to more effective and efficient efforts,” Fox said.
While the observed effect sizes are small, they are similar to those seen with other protective factors such as not smoking or engaging in high physical activity levels. The study also noted that women who had experienced pregnancy scored 0.60 points higher on cognitive ability tests than those who had not; women who breastfed scored 0.19 points higher on overall cognitive ability and 0.27 points higher on verbal memory compared to those who never breastfed.
The research acknowledges that while there is a connection between reproductive history and brain resilience later in life, further investigation is needed into the biological and sociocultural mechanisms behind this relationship. The authors wrote that “more adult children could be a factor in the increased cognitive health, as supportive relationships could possibly buffer stress, promote well-being or encourage healthy behavior.”
“If we can figure out, as a next step, why those reproductive patterns lead to better cognitive outcomes in old age, then we can work toward figuring out how to craft therapies — for example, new drugs, repurposed drugs or social programs — that mimic the naturally-occurring effect we observed,” Fox said.
This study adds evidence that reproductive experiences may play a role in women’s brain health over time and could help inform preventative strategies targeting populations at greater risk for Alzheimer’s disease.
The research was conducted by the Women’s Health Initiative and received funding from the National Heart, Lung and Blood Institute under the National Institutes of Health; Fox was supported by the National Institute on Aging at NIH.