:max_bytes(150000):strip_icc():format(jpeg)/Health-GettyImages-2177734339-d7f55699145e41a586b769183b7726dd.jpg "Daytime sleep after working late. Exhausted woman catches up on sleep in the bright morning light.")
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- New research suggests that both too little and too much sleep may be linked to accelerated biological aging.
- However, biological aging was lowest among people who slept within an optimal range.
- Regularly sleeping more than eight hours a night could suggest an underlying health condition.
When it comes to sleep, more isn’t always better. A large new study found that not only was too little shuteye linked to accelerated biological aging, but also too much. Meanwhile, routinely hitting a sleep sweet spot was associated with the least amount of biological aging, researchers reported in the journal Nature.
The Ideal Amount of Sleep for Slower Biological Aging
Researchers pinpointed 6.4 hours to 7.8 hours of sleep per night as the range associated with slower rates of biological aging. That’s a measure of the body’s age at the cellular level, and it usually gives a more complete picture of health than your actual age.
“We’ve known for a while that poor sleep is linked to individual disease, such as heart disease, diabetes, dementia,” said Yue Leng, PhD, a study author and associate professor of psychiatry at UCSF Weill Institute for Neurosciences who wasn’t involved with the research. “But this study is the first to show, in a single analysis, that sleep duration has a consistent ‘U-shaped’ relationship with biological aging across the entire body.”
To reach that conclusion, researchers analyzed health data from more than 500,000 people included in the UK Biobank, a long-running biomedical database. Using 23 “epigenetic clocks”—algorithms that estimate biological age using data such as organ imaging, blood proteins, and metabolites—the researchers assessed the biological age of 17 organs, including the brain, heart, and lungs. They then compared those findings with participants’ self-reported sleep hours.
After crunching the numbers, a clear pattern emerged: sleeping more than eight hours or fewer than six hours a night was linked to faster biological aging.
A New Way To Look at Sleep—With Important Caveats
According to senior study author Junhao Wen, PhD, an assistant professor of radiological sciences at Columbia University Vagelos College of Physicians and Surgeons, understanding the link between sleep and aging “in a holistic, brain-body context” is necessary to create more precise ways for people to manage their sleep. He said the findings could help clinicians tailor different approaches for “short and long sleepers.”
“Since sleep problems affect so many people, this research could have a major impact on public health and quality of life for millions of individuals,” added Michelle Drerup, PsyD, the director of education and behavioral sleep medicine at the Sleep Disorders Center at Cleveland Clinic.
Still, the study comes with important caveats. For one, the data was self-reported, which can introduce inaccuracies. And while the study suggests patterns, Wen stressed that the results don’t necessarily apply at the individual level, nor should they be used to prescribe exactly how much sleep people need to stay healthy.
That’s partly because excessive sleep may not be the problem itself, experts said, but rather a signal of underlying health issues that could contribute to accelerated aging. For example, the study linked longer-than-normal sleep with depression later in life.
“So, with long sleep, the message isn’t ‘sleeping too much is poisoning you,’ Leng explained. “It’s more, if you’re consistently sleeping nine or 10 hours and still feel unwell, your body may be trying to tell you something important about your underlying health.”
Too little sleep, meanwhile, may be more directly linked to speedy aging. It can increase inflammation, impair cells’ ability to repair damage, and “raise cortisol and sympathetic nervous system activity in ways that accelerate cellular aging across multiple tissues,” Wen said.
For the average adult ages 18 to 60, the Centers for Disease Control and Prevention (CDC) recommends at least seven hours of sleep per night.
Simple Ways to Support Healthy Sleep
It’s not just too little sleep that may affect health, but also sleep quality, Leng stressed. Fragmented sleep, irregular sleep timing, and disrupted circadian rhythms can all negatively affect your health.
To get more—and better—shuteye, Leng advised focusing on consistency, including regular bed and wake times. She also suggested avoiding alcohol and screens close to bedtime, and getting bright light exposure in the morning to “help anchor your circadian clock.”
Pay attention to your sleep environment, Leng added. A “cool, dark, and quiet” bedroom can make a difference, she said.
If you’re routinely snoring loudly, have pauses in breathing during sleep, or find yourself gasping for air during sleep, it’s a good idea to speak to a doctor. “Sleep apnea is extremely common, often undiagnosed, and independently accelerates cardiovascular and brain aging,” Leng said.
Finally, if you start sleeping significantly less or more than usual, she said, it may be worth noting and bringing up the changes with a medical provider.
