Getting too little sleep may harm the body. But sleeping too much may also be a problem. A new study reveals that both short and long sleep contribute to accelerated aging in various organs of the body. These include the brain, heart, lungs, and immune system. Junhao Wen from the Columbia University Vagelos College of Physicians and Surgeons led the study. The findings were published in the journal Nature.
Researchers say sleep is essential for keeping the body healthy. Earlier studies mainly focused on how sleep affects the brain. But this new research found that sleep may affect the entire body in many different ways. Wen stated that the study reveals a link between both insufficient and excessive sleep and accelerated aging in nearly every organ. He explained that sleep helps support the body’s balance, metabolism, and immune system. The researchers used something called “aging clocks.” These are tools powered by machine learning.
They measure how fast a person’s body is aging compared to their real age. Scientists create these clocks using biological data such as proteins, blood samples, scans, and other medical information. Most aging clocks study the whole body. But Wen’s team created clocks for specific organs. This helped them understand how different body parts age separately.
The researchers wanted to know if lifestyle habits could affect aging. Sleep became an important focus because scientists already believed it played a major role in health. To carry out the study, the team used data from about 500,000 people in the UK Biobank.
The UK Biobank is a large health database. It keeps medical and lifestyle details from many volunteers. Scientists used machine learning to study aging in different organs. They checked medical scans, proteins, blood markers, and metabolism data. For example, the liver was studied using protein data, metabolism information, and scan results. The researchers were able to find signs of aging in the body.
This allowed researchers to compare sleep patterns with different signs of aging inside the same organ. The team then compared sleep duration with aging rates in 23 aging clocks across 17 organ systems. The results showed a clear U-shaped pattern. People who slept less than six hours each night often showed faster aging. The same thing happened in people who slept more than eight hours. The healthiest aging patterns were found in people who slept between 6.4 and 7.8 hours a night. Researchers said the finding does not prove that sleep directly causes faster aging.
However, sleep length may be a sign of overall health problems inside the body. The study also found strong links between sleep and many diseases. People who sleep too little have higher chances of depression and anxiety. Short sleep was also linked to obesity, type 2 diabetes, high blood pressure, and heart problems. Both too little and too much sleep are connected to lung diseases like asthma and COPD. People with unhealthy sleep habits also had more digestive problems.
These included gastritis and acid reflux disease. Researchers believe the findings show that sleep affects the whole body, not just the brain. Wen said sleep is deeply connected to the body’s overall health and functions. The team also took a closer look at late-life depression. They wanted to understand how sleep and aging work together in this condition.
The researchers used a method called mediation analysis to study the link between sleep and depression. They found that aging in some organs may play a role. The results suggested that short sleep could increase the risk of depression later in life.
Long sleep, however, may affect depression through aging in the brain and body fat tissue. This means short and long sleep may lead to the same condition in different ways. Wen said these findings could help doctors create better treatments in the future. Wen explained that people who take little sleep and people that take too much sleep may need different approaches for treatment and care. The study indicates that healthy sleep habits are very important. Experts say sleep is not just for feeling rested; it also helps the body age in a healthy way and may lower disease risks over time. Researchers hope future studies can find if better sleep can slow aging.
