This Type Of Sleep Is A Missing Part Of Your Anti-Aging Routine

After a few nights of inconsistent sleep, everything can feel harder.

You're tired, your workout feels tougher, and your usual routine feels off. Sleep is often treated as a numbers game, with seven to nine hours as the goal, but how you sleep may matter, too.

In new research involving nearly 100,000 adults, scientists examined several aspects of sleep and compared them with markers of aging and disease risk. The results point to one part of sleep that's easy to overlook.

About the study

Researchers analyzed data from 93,249 adults in the UK Biobank.

Each participant wore a wrist-based activity tracker for seven days, allowing researchers to estimate total sleep time, deep sleep, REM sleep, light sleep, nighttime wakefulness, and changes in sleep duration from night to night.

They compared these sleep patterns with nine "hallmarks of aging," biological changes that occur with age, including changes in how cells repair themselves, manage energy, and maintain healthy proteins.

Blood samples from a subset of participants were also analyzed for proteins involved in sleep and aging.

What healthier sleep looked like

People who slept longer, spent more time in deep sleep, or got more REM sleep generally had lower risk across several aging markers.

An extra hour of total sleep was associated with lower risk of problems related to stem cell function and the body's ability to regulate energy and nutrients.

More REM sleep had the strongest association with lower risk of stem cell exhaustion among the sleep patterns studied.

The reverse was also true. More time awake after falling asleep and greater variation in sleep duration from night to night were associated with higher risk across several aging markers.

Light sleep wasn't significantly associated with any of the nine markers. The researchers also examined specific diseases. Longer total sleep, deep sleep, and REM sleep were associated with lower risk of metabolic, circulatory, and neurodegenerative conditions.

Each additional hour of sleep was associated with a 24% lower risk of Parkinson's disease.

The part of sleep you may not be tracking

We tend to ask one question about sleep: Did I get enough?

This research suggests asking another. How different was last night from the night before?

Sleep irregularity was associated with aging-related health risks even after researchers accounted for age, weight, physical activity, and smoking.

Irregular sleep has been tied to other outcomes as well, including eye health. This doesn't mean one late night or weekend lie-in will affect your health. The findings suggest that consistently shifting sleep duration may be another part of the sleep picture.

There are important limitations.

This was an observational study, so it can't show that inconsistent sleep causes disease. Sleep was measured for only seven days, which may not represent participants' usual patterns, and sleep stages were estimated with an algorithm rather than a clinical sleep study.

Participants were also predominantly white and European, so the findings may not apply equally to every population.

How to make your sleep schedule a little steadier

You don't need to obsess over sleep data to put these findings into practice.

The takeaway

Sleep duration, sleep stages, and regularity were all associated with aging-related health outcomes in this large study. A consistent sleep routine may deserve as much attention as the number of hours you get.