Summary: UCLA researchers report that new mothers who slept less than seven hours per night at six months postpartum showed biological age increases of roughly three to seven years compared with mothers who averaged seven or more hours of sleep.
Source: UCLA
New mothers often say sleepless nights make them feel years older, and recent research from UCLA published in the journal Sleep Health supports that perception. The study links short sleep in the early postpartum months to signs of accelerated biological aging.
Researchers followed 33 women through pregnancy and the first year after childbirth, analyzing blood samples to estimate biological, or epigenetic, age. The analysis showed that mothers who were sleeping less than seven hours per night at six months postpartum had biological age estimates three to seven years higher at one year after birth than mothers sleeping seven or more hours. In addition, those with shorter sleep had shorter telomeres in their white blood cells—protective DNA caps whose shortening has been associated with higher risk for cancer, cardiovascular disease, and earlier mortality.
Study lead author Judith Carroll, UCLA’s George F. Solomon Professor of Psychobiology, emphasized the broader health significance: “A growing body of evidence shows that getting fewer than seven hours of sleep per night harms health and raises the risk of age-related disease. Our findings suggest that the sleep loss many new mothers experience in the early postpartum months could have measurable effects on biological aging.”
Participants’ reported nightly sleep varied from about five to nine hours. More than half of the women were getting less than seven hours both at six months and at one year postpartum. Carroll noted a clear relationship between sleep duration and biological age: “Each additional hour of sleep was associated with a younger biological age,” she said. “Many sleep scientists now consider sleep health as essential as diet and exercise for overall well-being.”
Carroll encouraged new mothers to prioritize sleep when possible—nap when the baby sleeps, accept offers of help from friends and family, and arrange for partners to share nighttime or early-morning care when feasible. “Taking care of your sleep needs benefits both you and your baby over time,” she said.
Co-author Christine Dunkel Schetter, a distinguished professor of psychology and psychiatry at UCLA, called the results an additional rationale for stronger support for parents of infants. She suggested policies and programs—such as parental leave and family support initiatives—that help both parents share caregiving responsibilities and allow mothers to obtain more restorative sleep.
Dunkel Schetter also cautioned that accelerated biological aging linked to sleep loss does not necessarily imply permanent harm. “These findings do not mean mothers are permanently damaged by infant care and sleep disruption,” she said. “We do not yet know whether the effects persist long term or can be reversed.”
Using epigenetics to estimate biological age
The study used established epigenetic techniques to assess biological aging. Epigenetics examines whether regions of DNA are accessible or effectively “turned off”—a process that changes predictably with age and can serve as a molecular clock. Carroll offered an analogy: DNA is like a grocery store with many aisles; if an aisle is closed, items from that section are unavailable. When genetic regions are “closed” by epigenetic marks, the genes there cannot be expressed, which contributes to the measurable pattern known as epigenetic aging.
Because epigenetic marks change in consistent ways with age, researchers can estimate an individual’s biological or epigenetic age. Higher epigenetic age is associated with greater disease risk and earlier mortality in population studies. The UCLA team notes that their sample was modest—33 women aged 23 to 45 at six months postpartum—so larger studies are needed to confirm these findings and to determine whether the observed effects are temporary or long-lasting.
Carroll and Dunkel Schetter previously reported evidence that a mother’s prenatal stress may accelerate biological aging in her child, suggesting possible intergenerational pathways for health risk. The current paper’s co-authors include researchers from UCLA departments of psychology, psychiatry and biobehavioral sciences, human genetics and biostatistics, and collaborators at the University of Colorado at Colorado Springs.
Funding: The research received support from the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute on Aging, both part of the National Institutes of Health.
About this sleep and aging research news
Source: UCLA
Contact: Stuart Wolpert – UCLA
Image: The image is in the public domain
Original Research: Closed access. “Postpartum sleep loss and accelerated epigenetic aging” by Judith Carroll et al., Sleep Health.
Abstract
Postpartum sleep loss and accelerated epigenetic aging
Background
Insufficient sleep has been associated with accelerated biological aging in adults, which may help explain links between short sleep and higher disease risk. This study tested whether short sleep during the postpartum period predicts older biological age one year after birth, as measured by epigenetic aging markers.
Methods
As part of the Healthy Babies Before Birth (HB3) study, 33 mothers provided blood samples that were analyzed to estimate several epigenetic aging measures: intrinsic epigenetic age acceleration (IEAA), extrinsic epigenetic age acceleration, phenotypic epigenetic age acceleration (PEAA), GrimAge, DNAmPAI-1, and DNAm telomere length (TL). Sleep duration was categorized as insufficient (<7 hours/night) or sufficient (7+ hours/night). Sleep quality was assessed with the Pittsburgh Sleep Quality Index (global score >5 indicating poor quality).
Results
Sleep duration at six months postpartum—but not at 12 months—predicted older biological age at 12 months for several measures: IEAA (B = 3.0, SE = 1.2, P = .02), PEAA (B = 7.3, SE = 2.0, P = .002), and shorter DNAm telomere length (B = −0.18, SE = 0.07, P = .01). Other indices did not show significant relationships. Self-reported poor sleep quality at 6 or 12 months was not significantly related to epigenetic age.
Conclusions
These results indicate that insufficient sleep during the early postpartum period is linked with markers of accelerated biological aging. Given the small sample size, further research with larger and more diverse samples is needed to replicate the findings and to determine the duration and reversibility of the observed effects.