Sleeping Too Little or Too Much: Discovering the Surprising Relationship Between Sleep and Premature Aging

Sleeping too little is bad. Sleeping too much is also bad. Now, scientists have discovered that both can accelerate the aging of the body and increase the risk of serious diseases.

Sleep is much more than just a time for rest. While we sleep, the body performs a series of essential processes to keep the brain, heart, metabolism, and immune system functioning properly. In recent decades, scientists have come to realize that sleeping too little can cause significant harm to health.

However, more recent studies show that sleeping excessively can also be related to physical and mental problems. Now, new international research suggests that both insufficient sleep and prolonged sleep can accelerate the aging of the body.

Researchers wanted to understand how sleep duration influences so-called "biological aging." Unlike the age shown on the calendar, biological aging attempts to measure the true state of wear and tear on the body. In some people, the body may appear biologically older or younger than their chronological age.

To investigate this, scientists analyzed data from nearly 500,000 people in the United Kingdom, using information from medical exams, blood tests, brain images, and reports on sleep habits.

The most innovative part of the study was precisely the way aging was measured. Scientists used tools known as "biological clocks," capable of estimating the age of the body's organs and tissues based on chemical and structural signals.

To do this, they analyzed proteins present in the blood, substances produced by metabolism, and detailed images of the brain and other body systems. With this information, the researchers were able to compare the biological age of different parts of the body with the actual age of each participant.

After that, the researchers cross-referenced all this data with the sleep hours reported by the volunteers. The result revealed a very clear pattern: people who slept too little or too much showed more accelerated signs of aging in various organs.

According to the study, the range considered healthiest was between approximately six and a half hours and almost eight hours of sleep per night, although small differences were observed between men and women and between different body systems.

In addition to accelerated aging, scientists also found an association between extreme sleep patterns and a higher risk of disease and premature death. People who slept less than six hours or more than eight hours per night were more likely to develop problems such as depression, diabetes, and diseases in different parts of the body.

Researchers believe that inadequate sleep can directly affect important bodily processes such as inflammation, hormonal balance, metabolism, and brain function.

The authors emphasize that sleep is a factor that can be modified throughout life, making the results especially important for public health. Unlike genetic factors, sleep habits can be improved with changes in routine, treatment of sleep disorders, and greater attention to mental health. For the researchers, optimizing sleep quality and duration may become one of the most important strategies for promoting healthy aging, preventing disease, and increasing longevity.

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Sleep chart of biological aging clocks in middle and late life

The MULTI Consortium, Cliodhna Kate O’Toole, Zhiyuan Song, Filippos Anagnostakis, Zhijian Yang, Ye Ella Tian, Michael R. Duggan, Chunrui Zou, Yue Leng, Yi Cai, Wenjia Bai, Cynthia H. Y. Fu, Michael S. Rafii, Paul Aisen, Gao Wang, Philip L. De Jager, Jian Zeng, Hamilton Se-Hwee Oh, Xia Zhou, Keenan A. Walker, Daniel W. Belsky, Andrew Zalesky, Eleanor M. Simonsick, Susan M. Resnick, Luigi Ferrucci, Christos Davatzikos, and Junhao Wen. 

Nature

DOI:10.1038/s41586-026-10524-5

Abstract: 

Optimal sleep has a vital role in promoting healthy ageing and enhancing longevity. Here we propose Sleep Chart to assess the relationship between self-reported sleep duration and 23 biological ageing clocks derived from in vivo imaging1, plasma proteomics2 and metabolomics3. First, a systemic, U-shaped pattern emerges between sleep duration and biological age gaps across nine brain and body systems and three omics technologies. The sample-specific lowest biological age gaps are achieved between 6.4 and 7.8 h of sleep duration, varying by organ and sex in the UK Biobank (aged 37–84 years). Furthermore, short (<6 h) and long (>8 h) sleep duration, compared with a normal sleep duration (6–8 h), are associated with increased risk of systemic diseases beyond the brain and all-cause mortality, with evidence from genetic correlations and time-to-incident survival predictions, such as depression and diabetes. Finally, the pathways by which long and short sleep duration are associated with late-life depression differ: ageing clocks may partially mediate the pathway for long sleep duration, while short sleep duration shows a more direct link. Although Mendelian randomization does not provide strong evidence that disease causally affects sleep, it cannot completely exclude such reverse causality. Our findings suggest a cross-organ, multi-omics U-shaped relationship between sleep duration and biological ageing clocks, highlighting the potential of sleep optimization to promote healthy ageing, lower disease risk and extend longevity.