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• Posted October 28, 2021

Could Breastfeeding Help Women Keep Their Smarts as They Age?

Might breastfeeding affect a new mother's future brain health?

That's the intriguing question posed by a new study that flips the narrative from the often-touted benefits for baby to what impact breastfeeding might hold for Mom years later.

Researchers from UCLA Health found that women over age 50 who had breastfed their babies performed better on tests of brain function than those who had not.

"The findings were pretty straightforward in that we compared women who did versus did not breastfeed," said lead author Molly Fox, an assistant professor in the Departments of Anthropology and Psychiatry and Behavioral Sciences at the University of California at Los Angeles.

And women who did performed better on tests of thinking and memory skills, also known as cognition.

The findings are significant because impaired cognition after age 50 can be a strong predictor of Alzheimer's disease, the leading form of dementia and cause of disability in the elderly. About two-thirds of Americans with Alzheimer's are women.

"We repeated the analyses looking only at women who had children to make sure that we weren't just picking up an effect of whether or not you had children and the results were the same," Fox said. "It does seem to be that there was something connected to breastfeeding specifically, and not just whether or not you have kids."

The study included 115 women who were part of two 12-week clinical trials at UCLA Health. Sixty-four described themselves as depressed, and 51 as not depressed. All completed a questionnaire about their reproductive life history, including the age they began their period, number of pregnancies, length of time they breastfed for each child and their age at menopause.

The women also completed psychological tests that measured brain function in four areas: learning, delayed recall, executive functioning and processing speed. None had been diagnosed with dementia.

In all, 65% of women who said they were not depressed had breastfed, compared to about 44% of women with depression.

Whether they described themselves as depressed or not, women who had breastfed performed better in tests of all four brain functions evaluated compared to those who had not, the study found.

All four scores were significantly linked to breastfeeding in women without depression.

But only two were strongly associated with breastfeeding in the group with depression -- processing speed and executive function, which includes skills such as flexible thinking, self-control and working memory.

Women who had not breastfed had significantly lower scores in three of the four brain functions evaluated compared to women who had breastfed for one to 12 months. Additionally, their scores were lower in all four areas compared to women who breastfed for more than a year.

What's unique about breastfeeding

Though the researchers weren't able to directly examine what's connecting the two, they have some theories.

"I think it would make sense that there are some things that we know breastfeeding affects, like a woman's energy metabolism, lipid metabolism, and these are systems that are already implicated in brain aging and Alzheimer's risk," Fox said.

The intriguing -- and exciting -- possibility is that breastfeeding could exert effects on metabolism or other bodily functions that could be responsible for the pattern researchers saw.

"To address the question about what it means for women who did or did not have kids, the story is much more complex than the scientific study, because the actual lived experience in women's reproductive histories involves so many different phases and systems and we were only looking at this one factor," Fox said.

She noted that the study shows an association and doesn't prove cause and effect.

The link might not even have a biological cause, Fox said, but might owe to the psychological or social experience of bonding with your child or the family dynamics around breastfeeding.

Dr. Neelum Aggarwal, a fellow of the American Academy of Neurology and associate professor at Rush Medical College in Chicago, reviewed the findings.

"This is an interesting study as it expands our thinking about a woman's reproductive history and relatedness to cognitive decline and dementia," she said.

But more study is needed, Aggarwal said. Multiple factors and issues in society, including concerns about mood, depression, anxiety and how they may limit breastfeeding, should be investigated in a larger, diverse population, she said.

Dr. Nicole Smith, medical director at the Maternal-Fetal Medicine Clinic at Brigham and Women's Hospital in Boston, said breastfeeding can provide lifelong benefits to a mother's health. Among them are lowering her risk for heart disease, diabetes and breast cancer. Smith said the relationship between mental decline and breastfeeding may be related to those other factors.

"Whether or not a woman breastfed, however, is unlikely to be the most important variable in maintaining cognitive function," she said. "A healthy lifestyle, including optimizing cardiovascular health, is most likely to be beneficial."

In her practice, Smith said she aims to help women achieve their breastfeeding goals -- whatever they may be.

"Certainly we can have healthy babies and mothers when babies are formula-fed," she added.

The findings were recently published in the journal Evolution, Medicine, & Public Health.

More information

The U.S. Department of Health and Human Services Office on Women's Health has more on breastfeeding.

SOURCES: Molly Fox, PhD, assistant professor, Departments of Anthropology and Psychiatry and Behavioral Sciences, University of California at Los Angeles; Neelum Aggarwal, MD, associate professor, neurological sciences, Rush Medical College, Chicago, and neurologist, Rush Alzheimer's Disease Center, Chicago; Nicole Smith, MD, MPH, medical director, Maternal-Fetal Medicine Clinic, Brigham and Women's Hospital, Boston; Evolution, Medicine, & Public Health, Oct. 1, 2021