Too Little — or Too Much — Sleep May Age Your Body Faster, New Study Finds
Biological age has become a major focus of longevity research. Unlike the number of candles on your birthday cake, biological age is meant to show how old your body appears based on changes in its organs, tissues, and molecules. A new study asked whether these signs of aging are linked to one of the most important — and potentially changeable — parts of health: how long you sleep.
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A Small Window of “Ideal” Sleep
Two people can be the same age but show very different signs of ageing inside the body. Researchers can now use medical scans and blood tests to estimate the biological age of different organs. These estimates, known as “ageing clocks,” compare a person’s biological data with patterns typically seen at different ages.
For example, an organ may appear older or younger than expected for someone’s calendar age. The difference is called a biological age gap. For the study, published in Nature, researchers used data from the UK Biobank, a long-term health study involving roughly half a million adults in the United Kingdom. Participants were between 37 and 84 years old, although the number included differed across the analyses.
The researchers examined medical images, organ-related proteins in the blood and blood metabolites — small molecules produced as the body processes food, medicines and other substances. Using these data, they assessed 23 biological ageing clocks covering 17 organ systems. They then compared the results with how many hours participants said they usually slept each day.
A U-shaped pattern appeared in 9 of the 23 clocks. People who reported sleeping fewer than 6 hours or more than 8 hours generally had older-looking biological profiles, while the lowest ageing scores occurred between about 6.4 and 7.8 hours of sleep. The exact low point differed depending on the clock, though. For instance, brain-related blood proteins looked youngest among women reporting about 7.8 hours of sleep and men reporting about 7.7 hours, while brain scans looked youngest at about 6.5 hours for women and 6.4 hours for men.
“Too little and too much sleep are associated with faster aging in nearly every organ, supporting the idea that sleep is important in maintaining organ health within a coordinated brain-body network, including metabolic balance, and a healthy immune system,” Junhao Wen, assistant professor of radiology at Columbia University Vagelos College of Physicians and Surgeons and the study’s senior author, said in an academic news release.
Dr. Stefano Gaburro, who holds a doctorate in neuropharmacology and neuroscience and was not involved in the study, said the main advance was not the familiar finding that too little or too much sleep may be unhealthy. It was the range of biological measures the researchers examined throughout the body.
“Most sleep research looks at the brain,” Gaburro told Nifty50+. “That breadth is what is new here. The headline number is not.”
Sleep’s Body Wide Impact
The findings suggest that sleep is tied to health throughout the body, not only the brain. Short sleep shared genetic links with a wide range of conditions, including depression, anxiety, type 2 diabetes, heart failure and ischemic heart disease. This suggests that some of the biology linked to short sleep may also be involved in these conditions.
Long sleep showed a narrower pattern, mainly involving psychiatric and brain-related conditions such as major depression, schizophrenia, bipolar disorder and migraine. The researchers noted that long sleep may sometimes be a sign of an underlying illness or the body’s response to poor health rather than a direct cause of disease. The team also followed participants to see who later developed health problems.
Compared with people who reported sleeping 6 to 8 hours, short sleepers had a higher risk of obesity, type 2 diabetes, high blood pressure, ischemic heart disease, heart rhythm problems, depression and anxiety. Both short and long sleep were linked with respiratory and digestive conditions, including asthma, chronic obstructive pulmonary disease, gastritis and acid reflux.
“The broad brain-body pattern is important because it tells us that sleep duration is a deeply embedded part of our entire physiology, with far-reaching implications across the body,” Wen said.
Too little and too much sleep are associated with faster aging in nearly every organ, supporting the idea that sleep is important in maintaining organ health within a coordinated brain-body network …”
Junhao Wen, assistant professor of radiology at Columbia University and the study’s senior author
What This May Mean
The findings support the familiar idea that a moderate amount of sleep—roughly 6 to 8 hours in this study—is linked to healthier ageing profiles in middle and later life. But the study does not establish one perfect amount of sleep for everyone. It also does not show that sleeping more than 8 hours is automatically harmful. Gaburro cautioned that the study captured only one point in time.
The study also cannot determine whether unusual sleep patterns contribute to poorer health or whether existing health problems cause people to sleep more or less. As Gaburro put it, the findings show that sleep is closely connected with aging throughout the body, but “it does not tell us that changing your bedtime will slow that down.”
Sleeping longer than usual may reflect illness, depression, poor-quality or broken sleep, a sleep disorder, medication use or low activity levels. Sleeping too little may be related to insomnia, caregiving, shift work, pain or other health and lifestyle pressures. Sleep quality and regularity matter too, although this study focused mainly on the number of hours people said they slept.
For you, the goal is not to chase an exact number on the clock. Instead, pay attention to changes in your usual sleep pattern and how you feel during the day. If you regularly sleep much less or much more than usual—especially if you also experience daytime sleepiness, mood changes, loud snoring, pauses in breathing or worsening health — it may be worth discussing with a health professional.
