Prioritizing ample sleep each night matters, and a new study further emphasizes that sacrificing those hours has consequences.
In a study published this week in PLOS Journal, researchers at The University of College London used data from the Whitehall II study (a long-term study of British civil servants) to analyze over 7,000 civil servants in the United Kingdom over the course of 25 years, who reported how much they slept at about ages 50, 60 and 70 respectively. The study notes whether the participants developed a chronic condition, or multimorbidity, meaning having two or more of 13 chronic diseases: cancer, diabetes, heart disease, dementia, stroke, chronic obstructive pulmonary disease, chronic kidney disease, heart failure, liver disease, arthritis, Parkinson’s, depression and other mental health disorders.
As the aging population grows, so has the number of people grappling with multiple chronic conditions. Previous research shows that there’s a lack of information about risk factors for developing multiple chronic conditions, including sleep health.
“As people get older, their sleep habits and sleep structure change,” says Dr. Severine Sabia, author of the study and research associate at the UCL Institute of Epidemiology & Health in a press release. “However, it is recommended to sleep for 7 to 8 hours a night as sleep durations above or below this have previously been associated with individual chronic diseases.”
The study found that sleeping five or fewer hours a night at age 50, 60, and 70 was associated with an increased risk of developing multiple chronic conditions over time compared to sleeping seven hours. Shorter sleep durations at age 50 were associated with a 20% higher risk of developing one chronic health condition and an increased risk of developing more than one. Sleeping nine or more hours of sleep was also associated with multimorbidity at age 60 and 70, although not statistically significant at age 50, according to the study.
“This research is important because it brings attention to the importance of sleep health, and more acknowledgement about how important sleep health is with regards to health overall: mental health [and] physiological health,” Dr. April Rogers, a sleep research scientist and assistant professor at St. John’s University in the division of health and human services, who was not involved in the study, tells Fortune. The more awareness around the effects of sleep, the more “impactful information” the public will receive about how to rest and restore, she says.
Still, she notes that further research into a wider population is needed, as the study’s participants were majority white men and all civil servants, meaning they had job stability.
Sleep quality, and the ability for the body to regulate hormones, is as crucial as sleep duration, Rogers says. Falling into slow-wave sleep, or deep sleep, is an important step in that process and sleep routines help pave the way.
“Have a consistent sleep schedule. Have a sleep environment that is dark, that is quiet, that is thermal regulated,” she says, adding that limiting large meals, caffeine and alcohol right before bed also promotes optimal sleep quality.
