- Researchers say falling asleep between 10 p.m. and 11 p.m. is the best time for heart health.
- They say that optimum bedtime fits well with circadian rhythms and daylight exposure.
- Experts say having a consistent bedtime routine, as well as exercising and eating at the proper times, can help you fall asleep at a healthy hour.
For many people, bedtime is whenever they can fall asleep.
However, researchers say there actually is an ideal time to crawl under the covers for the sake of your heart health.
According to a new study from the United Kingdom, if you want to protect your heart, get to bed between 10 p.m. and 11 p.m.
“Our study indicates that the optimum time to go to sleep is at a specific point in the body’s 24-hour cycle and deviations may be detrimental to health,” said Dr. David Plans, a study author and a senior lecturer in organizational neuroscience at the University of Exeter, in a press statement. “The riskiest time was after midnight, potentially because it may reduce the likelihood of seeing morning light, which resets the body clock.”
“The body has a 24-hour internal clock, called circadian rhythm, that helps regulate physical and mental functioning,” Plans explained. “While we cannot conclude causation from our study, the results suggest that early or late bedtimes may be more likely to disrupt the body clock with adverse consequences for cardiovascular health.”
“Studies have shown that poor sleepers for any reason live a shorter life,” added Dr. Thomas Kilkenny, the director of sleep medicine at Staten Island University Hospital in New York.
“This report,” he told Healthline, “goes even a step further to show timing of sleep onset also can be a contributor to good cardiovascular health and that, if you go to sleep too early or too late, it adversely increases cardiovascular risks.”
The study involved more than 88,000 people aged 43 to 79 who agreed to collect data on their bedtime and wake-up time over a 7-day period using an accelerometer.
Participants also completed demographic, lifestyle, health, and physical assessments.
Researchers then tracked the study group over a 5.7-year period for diagnoses of cardiovascular disease, such as a heart attack, heart failure, chronic ischemic heart disease, stroke, and transient ischemic attack.
The researchers said that 3 percent of study subjects later developed cardiovascular disease. The incidence was highest in those with sleep times at midnight or later and lowest in those with sleep onset between 10 p.m. and 10:59 p.m.
Compared with sleep onset during this golden hour, there was:
- 25 percent higher risk of cardiovascular disease among those who fell asleep at midnight or later
- 12 percent greater risk of cardiovascular disease for those who began sleeping between 11:00 p.m. and 11:59 p.m.
- 24 percent increased risk of cardiovascular disease for those who fell asleep before 10:00 p.m.
The association between sleep onset and cardiovascular risk was higher among women, the researchers found.
“It may be that there is a sex difference in how the endocrine system responds to a disruption in circadian rhythm,” Plans said. “Alternatively, the older age of study participants could be a confounding factor, since women’s cardiovascular risk increases post-menopause.”
Many studies have shown that lack of sleep is a risk factor for cardiovascular disease.
People who get less than 7 hours of sleep nightly are at a
Researchers have rarely tried to pin down a perfect bedtime for heart health.
“If our findings are confirmed in other studies, sleep timing and basic sleep hygiene could be a low-cost public health target for lowering risk of heart disease,” Plans said.
“There is an increasing body of evidence which indicates that, when we sleep, in addition to how we sleep, may also be an important factor contributing to cardiovascular health,” Dr. Harly Greenberg, the chief of the Division of Pulmonary, Critical Care and Sleep Medicine at Northwell Health in New Hyde Park, New York, told Healthline.
“Importantly, adverse health effects may occur when our sleep schedule is ‘misaligned’ with our circadian rhythm on a regular basis. That is, when our busy schedules make us sleep at times other than our optimal time for sleep as determined by our biological clock,” Greenberg continued.
However, Greenburg noted that the 10 p.m. to 11 p.m. ideal sleep window identified in the study might not apply to everyone. More research is needed.
“Optimal circadian timing of sleep may vary for some people, especially those who are ‘morning larks’ or ‘night owls,’” Greenburg said.
The CDC recommends several steps toward getting adequate sleep, including:
- sticking to a regular sleep schedule
- going to bed at the same time each night and getting up at the same time each morning, including on weekends
- getting enough natural light, especially earlier in the day (A morning or lunchtime walk can help.)
- getting enough physical activity during the day — but not exercising within a few hours of bedtime
- avoiding artificial light, especially within a few hours of bedtime (Try using a blue light filter on your computer or smartphone.)
- not eating or drinking within a few hours of bedtime, and avoiding alcohol and foods high in fat or sugar
- keeping your bedroom cool, dark, and quiet
“The number one tip for achieving our sleep goals is to specifically set aside an appropriate amount of time for sleep and to maintain a strict schedule,” Kilkenny said.
“Often times, we tend to fit in sleep when we can, allowing work and social schedules to interfere with good sleep timing. Sleep is one of the three things we humans must do to survive. Eat, drink, and sleep. Everything else is pretty much an elective,” he added.