Do New Mothers Age Faster If They Don’t Get Enough Sleep? When new mothers grumble that all those sleepless hours caring for their children are robbing them of years, a UCLA study published this summer in the journal Sleep Health reveals that they may be correct.
The researchers followed 33 mothers throughout their pregnancies and the first year of their infants’ lives, testing their DNA from blood samples to estimate their “biological age,” which may differ from chronological age. They discovered that a year after giving birth, mothers who slept fewer than seven hours per night at the six-month mark had a biological age that was three to seven years older than mothers who slept seven hours or more.
Mothers who slept less than seven hours per night also had white blood cell telomeres that were shorter. These little fragments of DNA at the ends of chromosomes operate as protective caps, similar to the plastic tips on shoelace ends. Telomere shortening has been associated with an increased risk of cancer, cardiovascular, and other disorders, as well as earlier mortality.
“The early months of postpartum sleep deprivation may have a lasting influence on physical health,” said Judith Carroll, UCLA’s George F. Solomon Professor of Psychobiology and the study’s first author. “A substantial body of research has established that sleeping less than seven hours per night is hazardous to health and increases the chance of developing age-related disorders.”
While participants’ weekly sleep duration ranged between five and nine hours, the researchers indicate that more than half slept fewer than seven hours six months and one year after giving birth.
“We discovered that for every additional hour of sleep, the mother’s biological age decreased,” said Carroll, a member of UCLA’s Jane and Terry Semel Institute for Neuroscience and Human Behavior’s Cousins Center for Psychoneuroimmunology. “I, along with a large number of other sleep scientists, believe that sleep health is just as critical to overall health as food and exercise.”
Carroll recommended new moms to take advantage of opportunities to catch up on sleep, such as napping during the day while their baby sleeps, accepting offers of assistance from family and friends, and, when possible, enlisting their partner’s aid with the baby throughout the night or early morning. “Meeting your sleep demands will benefit both you and your kid in the long run,” she explained.
Co-author Christine Dunkel Schetter, a distinguished professor of psychology and psychiatry at UCLA, stated that the study’s findings “and other findings on maternal postpartum mental health provide the impetus for better-supporting mothers of young infants so that they can get adequate sleep — possibly through parental leave to alleviate some of the care burdens, and through programs for postpartum depression.”
Dunkel Schetter emphasized that, while rapid biological aging associated with sleep deprivation may increase women’s health risks, it did not always result in bodily injury. “We don’t want the message to be that infant care and sleep deprivation permanently harm women,” she added. “We do not know how long these impacts will endure.”
‘This aisle is closed’: Determining biological age through epigenetics
Dunkel Schetter explained that the study used cutting-edge scientific tools for measuring DNA alterations to determine biological aging, commonly known as epigenetic aging. DNA contains the instructions for building proteins, which perform a variety of roles in our body’s cells, and epigenetics examines whether certain portions of this code are “open” or “closed.”
“Consider DNA as a grocery store,” Carroll explained, “with a variety of fundamental ingredients from which to construct a meal.” If an aisle is closed due to a spill, you may be unable to obtain an item from that aisle, which may prohibit you from completing a recipe. When access to DNA code is restricted,’ the genes encoding specific proteins are unable to be produced and are thereby switched off.”
Because specific regions inside DNA are turned on or off as a result of aging, Carroll explained, the process serves as a clock, allowing scientists to determine an individual’s biological age. The older someone is biologically, or epigenetically, the greater his or her risk of disease and mortality.
The study’s cohort — which included women aged 23 to 45 six months after giving birth — is not a large representative sample of women, the authors noted, and additional research is needed to better understand the long-term impact of sleep loss on new mothers, the additional factors that may contribute to sleep loss, and whether the biological aging effects are permanent or reversible.
Carroll and Dunkel Schetter reported last year that a mother’s stress prior to giving birth may accelerate her child’s biological aging, Dunkel Schetter explained. This is a sort of “intergenerational risk transfer.”
The new study was co-authored by researchers from UCLA’s departments of psychology, psychiatry and biobehavioral sciences, and human genetics and biostatistics, as well as the University of Colorado at Colorado Springs’ department of psychology.
The study was funded in part by the National Institutes of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute on Aging.