The researchers pinpointed a surprisingly specific sleep range for healthy aging.
Reviewed by Dietitian Katey Davidson, M.Sc.FN, RD, CPT
Key Points
- Your sleep quality can affect many systems in the body, from heart to brain health.
- A study suggests 6.4 to 7.8 hours of sleep each night may be linked to healthier aging.
- A consistent sleep schedule and calming sleep environment can promote better sleep.
The quality of our sleep is often considered a cornerstone of health, and for good reason. But despite its importance, many adults still fall short on sleep or experience sleep disturbances most nights, often thanks to busy work schedules, family responsibilities and life in general.
Beyond just how rested we feel each day—plus effects on heart and brain health—sleep may also play a role in how we age over time. And while both too little and too much sleep have been associated with a range of negative health outcomes, sleep is one of the more powerful lifestyle factors we can change—meaning small shifts in your sleep habits may help support healthier aging and lower chronic disease risk over time.
That’s exactly what a group of researchers set out to explore in a recent study published in Nature. Specifically, they looked at how sleep duration relates to biological aging across multiple organs and body systems, assessing how “old” your body appears at a molecular level. And overall, the findings suggest that sleep isn’t just about feeling rested on a day-to-day basis—it may also be linked to how quickly different systems in the body age over time.
How Was the Study Conducted?
For this study, researchers analyzed data from large population databases, including the UK Biobank—a comprehensive dataset of biological, health and lifestyle information from hundreds of thousands of individuals. The data researchers pulled included participants’ self-reported sleep habits, brain imaging, blood biomarkers, health records and long-term health outcomes.
Researchers wanted to determine whether the amount of sleep people get was associated with biological aging across various organ systems in the body. To do this, participants reported their usual sleep duration, and researchers put them into groups based on how many hours they slept each night.
Next, they compared the different sleep patterns and durations with 23 measures of biological aging. Instead of looking only at participants’ chronological age, researchers used biological aging clocks—tools that estimate how old different organs and body systems appear based on biomarkers like brain scans and blood measurements. This allowed researchers to determine whether people with different sleep habits showed signs of increased or decreased biological aging across multiple systems in the body.
Finally, researchers examined whether sleep duration and biological aging were associated with future adverse health outcomes, including depression, type 2 diabetes, heart disease and overall mortality.
What Did the Study Find?
After analyzing the data, researchers found that both short sleep (less than six hours per night) and long sleep (more than eight hours per night) were associated with signs of increased biological aging, while sleeping between six and eight hours was linked with the lowest levels of biological aging. Based on their findings, researchers identified an optimal sleep duration of about 6.4 to 7.8 hours per night.
Notably, researchers found that this relationship between sleep and aging wasn’t limited to a single organ or body system. Instead, associations were observed between sleep duration and biological aging across multiple systems throughout the body, including the brain, the heart and immune-related pathways. This suggests that sleep may influence whole-body aging rather than affecting just one part of the body or one aspect of overall health.
The findings also revealed that both short and long sleep duration were linked with a greater risk of several chronic conditions, including depression, type 2 diabetes, heart disease and overall mortality. That said, researchers did point out that short and long sleep may affect health differently. Short sleep appeared to have a more direct relationship with adverse health outcomes through things like stress, inflammation and immune-system disruptions. On the other hand, long sleep may be less of a direct risk factor and more of a marker of underlying biological aging and other health issues. However, more research is needed to understand these differences.
It’s important to note that this study does have some limitations. For one, it was observational, which means researchers analyzed existing data and looked for patterns between sleep duration and biological aging rather than testing sleep changes in a controlled environment. Because of this, the study is only able to show associations—it’s unable to prove that sleep duration directly causes increased aging. Additionally, the sleep data researchers used was self-reported by participants, which is subject to human error and can be less accurate than objective measures of sleep.
How Does This Apply to Real Life?
Perhaps the biggest takeaway from this study is that when it comes to sleep, more isn’t necessarily better. Researchers found that both too little and too much sleep were associated with signs of accelerated biological aging, while the lowest levels of biological aging were seen among those sleeping roughly six to eight hours per night.
That doesn’t mean everyone should aim for exactly 6.4 to 7.8 hours of sleep each night. What’s defined as “normal” sleep is often associated with cultural and environmental determinants, and sleep needs vary from person to person based on other factors like age, activity level and overall health. However, the findings reinforce the idea that consistently getting an adequate amount of sleep may be an important part of supporting long-term health and healthy aging.
If you’re looking to improve your sleep quality and duration, here are a few simple strategies:
- Stick to a consistent schedule. Going to bed and getting up at the same time every day can help regulate your body’s internal clock.
- Create a relaxing environment. A cool, dark and quiet room may help promote more restful sleep.
- Limit screen time before bed. Turning off electronic devices at least 30 minutes before bedtime can help you wind down.
- Be mindful of alcohol intake. Alcohol can disrupt the quality of your sleep, so it’s best to limit your intake close to bedtime.
And, of course, an overall healthy lifestyle is important for supporting quality sleep, too. Regular physical activity, stress management and a balanced eating pattern can all play a role in supporting healthy sleep habits.
Our Expert Take
A recent study published in Nature suggests that there may be a sleep “sweet spot” when it comes to healthy aging. Researchers found that adults who slept between six and eight hours per night—specifically 6.4 to 7.8 hours—showed the lowest levels of biological aging. While both short and long sleep duration were linked to increased biological aging as well as adverse health outcomes, sleep is one important lifestyle factor you have the ability to change. Prioritizing healthy sleep habits may help improve sleep quality and support long-term health as you age.
Comments are closed.