WASHINGTON — When new mothers say that sleepless nights caring for their babies are taking years off their lives, they might be right. Researchers from the University of California Los Angeles (UCLA) have new insights. Their study explores sleep loss in new mothers and how it can speed up the aging process.

The study, “Postpartum Sleep Loss and Accelerated Epigenetic Aging,” was published in the journal “Sleep Health.”

The Connection Between Sleep and Biological Age

Scientists followed 33 mothers during pregnancy and the first year of their babies’ lives. They analyzed the women’s DNA from blood samples to find their “biological age.” This age can be different from a person’s chronological age. The study found something remarkable. A year after giving birth, some mothers showed signs of accelerated aging.

Mothers who slept less than seven hours a night at the six-month mark had a biological age three to seven years older than those who slept more. This suggests a direct link between sleep deprivation and the body’s aging clock.

The Role of Telomeres in Aging

The study also looked at telomeres. These are small pieces of DNA at the ends of chromosomes. They act like protective caps, similar to the plastic tips on shoelaces. Mothers who slept less than seven hours had shorter telomeres in their white blood cells. Shortened telomeres connect to a higher risk of cancers, cardiovascular disease, and earlier death.

“The early months of postpartum sleep deprivation could have a lasting effect on physical health,” said Judith Carroll. Carroll is the study’s first author and the George F. Solomon Professor of Psychobiology at UCLA.

She added, “We know from a large body of research that sleeping less than seven hours a night is detrimental to health and increases the risk of age-related diseases.”

Every Hour of Sleep Matters

The participants’ nightly sleep ranged from five to nine hours. More than half of the mothers got less than seven hours of sleep six months and one year after birth. The impact of each hour was significant.

“We found that with every hour of additional sleep, the mother’s biological age was younger,” said Carroll, a member of the Cousins Center for Psychoneuroimmunology at UCLA’s Jane and Terry Semel Institute for Neuroscience and Human Behavior. “I, and many other sleep scientists, consider sleep health to be just as vital to overall health as diet and exercise.”

Carroll encourages new mothers to seize any chance for extra sleep. This can include napping when the baby sleeps or accepting help from family and friends. When possible, she suggests asking a partner to help during the night.

“Taking care of your sleep needs will help you and your baby in the long run,” she said.

A Call for Better Support Systems

Co-author Christine Dunkel Schetter believes the research can help new parents share care burdens more equally. She is a distinguished professor of psychology and psychiatry at UCLA.

Schetter said the results “provide the impetus for better-supporting mothers of young infants so that they can get sufficient sleep.” This support could come through parental leave for both parents and programs for families and fathers.

However, she also noted that accelerated biological aging does not automatically cause harm. “We don’t want the message to be that mothers are permanently damaged by infant care and loss of sleep,” she said. “We don’t know if these effects are long-lasting.”

Understanding Epigenetic Aging

The study used advanced methods to assess biological aging, also known as epigenetic aging. DNA provides the code for making proteins, which perform many tasks in our cells. Epigenetics focuses on whether parts of this code are “open” or “closed.”

“You can think of DNA as a grocery store with lots of basic ingredients to build a meal,” Carroll explained. “If there is a spill in one aisle, it may be closed, and you can’t get an item from that aisle.” This closure prevents you from making a specific recipe. When access to DNA code is closed, the genes for certain proteins cannot be expressed.

This on-and-off process acts as a clock. It allows scientists to estimate a person’s biological age. A higher biological age means a greater risk for disease and earlier death.

The study’s authors caution that their group of 23- to 45-year-old women was not a large, representative sample. More studies are needed to understand the long-term impact of sleep loss. Future research could explore other factors contributing to sleep loss and whether the aging effects are reversible.

Carroll and Schetter previously reported in 2020 that a mother’s stress before birth may accelerate her child’s biological aging. This shows a form of “intergenerational transfer of health risk.”

Researchers from various departments at UCLA and the University of Colorado at Colorado Springs co-authored the new study. The Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute of Aging provided funding.