I’m often asked if the effects of motherhood on the brain will last forever. Short answer — yes! And this looks like a good thing.
I’m a neuroscientist, therapist, podcaster and mom of 2 who talks a lot about the neuroscience of parenting; shedding light on just how amazing your mom brain is and how much more we need to know about it in health and illness.
I recently wrote about how our Mom Brain is our Superpower for Inspire the Mind but perhaps a more pressing question is - will your brain ever function like it did before? The short answer is — once a parent always a parent — but that doesn’t mean your brain will be the same now as it will be in 5, 10 or even 40 years. It is ever-changing in relation to the needs of your child, your biology and what’s going on around you.
Ageing gracefully
In 2019, a leading journal of scientific research, PNAS, published the first paper using neuroimaging data to investigate how motherhood may affect the brain in middle-age. Prior to this work, the human data showed an effect of motherhood on the brain up to 2 years postpartum, however, research in animal models had suggested more enduring effects of motherhood on the brain. The study, headed by Dr. Ann-Marie de Lange, principal investigator of Femilab at the University of Lausanne, and a recent guest on my podcast Mommy Brain Revisited, looked at the relationship between the number of childbirths and markers of brain ageing in brain images of thousands of middle-aged women (50–60-year-olds) provided from the UK Biobank.
They investigated structural brain characteristics in grey matter using a magnetic resonance imaging (MRI)-derived biomarker of global brain ageing (basically fancy technology involving artificial intelligence and machine learning) and aimed to determine if measures of global brain age differed between middle-aged mothers and non-mothers as well as the impact of the number of births on these brain measures.
They found that women who had given birth had ‘younger-looking’ brains in middle-age and this effect was related to the number of children they had — showing that up to 4 may be optimal for this ‘younger-looking’ brain effect. Interesting!
I should also note that things such as age at menarche, age at menopause and number of incomplete pregnancies were controlled for as these factors can also affect brain health.
More recently work from Ann-Marie’s team shows that in middle and aged mothers (50–80 years old) there are specific brain areas that look particularly ‘younger’. These brain areas include the amygdala, hippocampus (my favourite), thalamus, accumbens and putamen — areas important for aspects of maternal caregiving and that play a role in the ‘parental brain circuit’.
The study further points out that the accumbens was most notably affected. The accumbens is part of the motivation and reward processing system in the brain which we know plays an important role in wanting to care for the baby in the early postpartum period.
How and why the accumbens remains to be affected by childbirth decades later is intriguing but, perhaps, speaks the ongoing motivation to care for your child. I know my mom checks in with all of us (there are 4) on an almost daily basis. She also loves to see me, even 40+ years later. [I like to think I’m still ‘rewarding’ .😉 ]
It should also be noted that you don’t have to have children to have an optimally functioning ageing brain. “It’s important to stress that these effects are quite moderate or small so whether you have children or not will definitely not determine how healthy your brain is when you age.…there are so many factors that influence how we age.” Ann-Marie told me on the podcast. This is important as many people are not parents for various reasons (choice, fertility challenges, etc).
A fountain of youth
Your mom brain is looking younger as you age, but how is this related to function and what about dads?
In 2020 by a team of researchers University of California also looked at brain ageing but they looked at both mothers and fathers in middle age and also investigated how parenting may affect visual memory. In brief, they found that younger-looking brains were evident in middle-aged moms and dads that had 2–3 children, in particular, and that in both parents having children was associated with better visual memory and faster response times. Cool, right?
This suggests that younger-looking brains could be linked to improved memory later in life but also that it’s not just the physiology of pregnancy and childbirth that is important, a number of lifestyle factors and time with children are likely key contributors to these younger-looking brains in both mothers and fathers.
In addition to this global measure of brain ageing, research headed by Winnie Orchard, a PhD Candidate at Monash University, who also joined me on the podcast, shows that mothers in their 70s have better verbal memory than non-mothers at the same age. Her work goes on to suggest that this improved memory could be linked to changes in cortical thickness in the parahippocampal gyrus of these mothers, a brain region involved in memory formation — where increased cortical thickness has been associated with better memory in old age. Fewer effects were seen in fathers. Further work from Winnie and her co-authors goes beyond these structural brain changes to look at brain activity in ageing parents. Again, with parents in their 70s, they found that in aged mothers, but not in aged fathers, there was “widespread decreasing functional connectivity with an increasing number of children parented”; meaning that decades after becoming a mom there are many changes in mom brain activity, changes that are also pointing to a ‘younger-looking’ brain.
Living life to the fullest
We see structural and functional effects of parenting on the ageing brain, most remarkably in mothers, but why? From the recent literature, it seems that likely candidates for these age-related changes in females who birth are hormonal and immunological factors — at least this is a theory.
Another likely contributor, in addition to these biological factors, is that time parenting matters. Many of the women in these studies were likely the primary caregivers given the typical gender roles of their time, but we must not forget that “Parenthood is a continuum of experience, and may represent a learning environment that is sustained for decades of an individual’s life” (Winnie Orchard) - A learning environment that can impact the brains of both mothers and fathers.