Getting a full night’s sleep may play a bigger role in life expectancy than many people realize. New research from Oregon Health & Science University suggests that regular sleep deprivation is associated with shorter life spans. The results were published in the journal SLEEP Advances.

Nationwide Data Shows Patterns Across the US

To reach their conclusions, the researchers analyzed a large national database and examined survey patterns on life expectancy in different counties across the United States. They compared county-level life expectancy figures with detailed survey data collected by the Centers for Disease Control and Prevention between 2019 and 2025.

When researchers examined lifestyle factors related to people’s life expectancy, sleep stood out significantly. Its correlation with life expectancy was stronger than that of diet, physical activity, or social isolation. Smoking was the only factor that had a greater impact.

“I didn’t expect it to correlate so strongly with life expectancy,” said lead author Andrew McHill, Ph.D., associate professor at the OHSU School of Nursing, the OHSU School of Medicine, and the Oregon Institute of Occupational Health Sciences at OHSU. “We’ve always thought sleep was important, but this research really underscores that point: People should really try to get seven to nine hours of sleep, if at all possible.”

Researchers Surprised by the Significance of the Findings

Much of the work was done by doctoral students in the Sleep, Chronobiology and Health Laboratory at the OHSU School of Nursing. Although scientists have long known that adequate sleep promotes overall health, the authors were still surprised by how closely sleep duration was linked to life expectancy. In the analysis, insufficient sleep was a more important predictor of life expectancy than diet and exercise.

“This is intuitive and makes perfect sense, but it was still impressive to see it so clearly in all these models,” McHill said. “I am a sleep physiologist and understand the health benefits of sleep, but the strength of the association between adequate sleep and life expectancy was remarkable to me.”

Previous studies have linked poor sleep to an increased risk of death, but this study is the first to show annual correlations between sleep and life expectancy in all US states. For their models, the researchers used the CDC’s definition of adequate sleep as at least seven hours per night, which is consistent with the recommendations of the American Academy of Sleep Medicine and the Sleep Research Society. In almost all states and in every year analyzed, the data showed a clear link between sleep duration and life expectancy.

Why Sleep Can Affect Life Expectancy

The study did not examine the biological reasons for this link. However, McHill pointed out that sleep plays a crucial role in heart health, immune function, and brain performance. During sleep, the body enters an important regeneration mode. Blood pressure and heart rate decrease, relieving strain on the cardiovascular system. Chronic sleep deprivation, on the other hand, is associated with high blood pressure, heart attack, stroke, and atherosclerosis. Since cardiovascular disease is one of the leading causes of death worldwide, poor sleep quality over a long period of time can significantly increase the risk of mortality.

The immune system is also heavily dependent on sleep. During the night, immune cells are activated and anti-inflammatory processes are regulated. People who regularly sleep too little are more susceptible to infections and often show an increased tendency to inflammation in the body. Chronic inflammation is considered a risk factor for numerous diseases such as diabetes, cancer, and heart disease. Sleep therefore plays an important role in keeping the body healthy and resilient.

Sleep also plays a crucial role in brain function. During the deep sleep phases, the so-called glymphatic system becomes active, removing metabolic waste from the brain. This cleansing process is important to prevent the accumulation of harmful proteins associated with neurodegenerative diseases. Sleep also supports memory formation, emotional stability, and the ability to concentrate. Persistent sleep deprivation, on the other hand, increases the risk of depression and possibly also dementia.

Last but not least, sleep influences metabolism and hormone balance. Too little sleep alters the regulation of hormones such as leptin and ghrelin, which control feelings of hunger and satiety, as well as cortisol, which is known as the stress hormone. This can result in increased appetite, weight gain, and an increased risk of type 2 diabetes. These factors also have a long-term effect on life expectancy.

Overall, it is clear that sleep influences almost all central biological processes in the body. It is therefore just as important as a balanced diet or regular physical exercise. A good and regular night’s sleep not only improves daily well-being, but can also make a decisive contribution to living a longer, healthier life. According to Hill, this research shows that we must give sleep at least as much priority as our diet or physical activity. Sometimes we view sleep as something we can put aside and perhaps postpone until later or the weekend. A good night’s sleep not only improves our well-being, but also our life expectancy.