How are you sleeping lately? Does it matter?
The answers to these questions may surprise you, as they did me. Getting enough sleep does matter, but how you sleep seems to matter, too.
Alex Janin, writing in The Wall Street Journal, says there is hope for those of us who live (and sleep) in the real world: Getting less than 8 hours of shut-eye a night doesn’t mean you’re doomed to an early grave. A recent study looking at sleep and longevity found that sleep “regularity”—going to bed and waking up at consistent times with few mid-slumber interruptions—matters more than how long you sleep. Sleeping six hours every night on a consistent schedule was associated with a lower risk of early death than sleeping eight hours with very irregular habits.
The study adds to a growing understanding of the links between sleep and longevity. Research in recent years has shown not only how important sleep is for health and lifespan, but also that the duration of sleep isn’t the only thing that matters.
“We’ve been missing maybe half of the story,” says Matt Walker, a neuroscientist and director of the Center for Human Sleep Science at the University of California, Berkeley, who wasn’t involved with the recent study. “Not just how much you sleep but the regularity with which you sleep has now come onto the map and exploded as perhaps the more important thing.”
More than a third of Americans don’t get the seven to nine hours of sleep recommended by sleep and medical organizations on a regular basis, according to Centers for Disease Control and Prevention data. Roughly 20% report rarely or never waking up feeling well rested, according to a recent U.S. News & World Report survey.
But there is hope for those of us in that third. A new study emphasizes the importance of regular sleep habits. The study, published in the journal Sleep, found that sleep regularity reduced the risk of premature death from any cause by 20% to 48% compared with those with the most irregular sleep. Irregular sleep habits included inconsistent sleep and wake times, interrupted sleep and napping. Sleep duration was still important: People who got long, consistent sleep had the lowest mortality risk, says Angus Burns, a research fellow at Harvard Medical School who co-wrote the study. But shorter, regular sleep was generally associated with lower mortality than longer, inconsistent sleep.
In a separate study, researchers looked at metrics such as how often people had trouble falling asleep and whether they used sleep medication. They found the healthiest sleepers had life expectancies of 4.7 years and 2.4 years longer than those with the worst sleep habits, for men and women respectively, according to the 2023 study published in the medical journal QJM.
Participants didn’t have to be perfect sleepers to reap longevity benefits, says Dr. Frank Qian, a cardiovascular disease fellow at Boston Medical Center and a lead author of the study. The benefits were cumulative with each additional good habit. Starting these good habits earlier in life also helped. “The longer you are able to maintain an optimal sleep pattern, that will probably have the greatest impact on your health and longevity,” he says.
There is an increased interest in the science of sleep. Among members of Life Extension and Anti-Aging, a longevity-focused Facebook group, sleep is one of the most frequent topics of conversation, says Nils Osmar, the group’s administrator. Just 1% of respondents to a September poll in the group said sleep isn’t a priority in the context of their health and longevity. Studies showing what aspects of sleep matter most for our long-term health can help us identify the habits to focus on. Even the healthiest sleepers had some variability in their bed and wake times, says Burns, who co-wrote the Sleep study, but he recommends people try to keep their sleep and wake times within a one to two-hour window.
I hope that includes my Sunday afternoon nap. I’m convinced that’s the key to living a long life, no matter what the study says.
