A new study led by Molly Fox, associate professor of anthropology at the University of California, Los Angeles, has found that an increase in cumulative time spent pregnant and time spent breastfeeding is associated with stronger long-term cognitive function for postmenopausal women.
For their study, the authors examined data from the Women’s Health Initiative Memory Study and the Women’s Health Initiative Study of Cognitive Aging, which annually assessed more than 7,000 women around age 70 for up to 13 years. They found that women who were pregnant for an average of 30.5 months, compared to those who had never been pregnant, were expected to have a 0.31 percent higher global cognition score. Compared to women who had never breastfed, women who had for an average of 11.6 months in their lifetime would be expected to have a 0.12 percent higher global cognition score.
The authors found that each additional month of pregnancy was associated with a 0.01-point higher overall cognitive ability score. Each additional month of breastfeeding demonstrated the same increase, as well as a 0.02-point higher verbal and visual memory score. Although these effects are small, the authors note that the increases in cognitive function from pregnancy and breastfeeding are similar to other known protective factors like non-smoking and high physical activity.
Going forward, the authors advocate for more research to identify which mechanisms link pregnancy and breastfeeding histories to improved cognitive function.
“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,” said Dr. Fox.
In addition to scholars at UCLA, the research team included authors from Saint John’s Health Center in Santa Monica, California, Wake Forest University, the University of California, San Diego, Harvard Medical School, the University of Arizona, the University of Texas Health Science Center at Houston, and the University of Oklahoma.