Sleep and a healthy heart is well established, researchers are still sussing out the details. A new study suggests there might even be an optimal time, within our 24-hour body clock, for falling asleep.
Sleep is the best way to relax and rejuvenate your body. It is what eliminates all the physical and mental stressors and reduces the risk of developing various illnesses, including cardiovascular complications. That said, while for some, bedtime starts as and when they fall off to sleep, research suggests that there could be an optimal time to go to bed so as to ensure a healthy heart.
According to a recent UK study, sleeping between 10 p.m. and 11 p.m. is the best time for heart health. The new research published in the European Heart Journal, collected data from more than 88,000 participants aged 43 to 79 in the U.K. Biobank study, who agreed to monitor their bedtime and wake-up time over a 7 days using an accelerometer.
Additionally, the volunteers underwent various physical, demographic, lifestyle and health assessments.
The study found that people who went to bed before 10 p.m. and later than 11 p.m were associated with a greater risk of developing cardiovascular disease than those who went to sleep between 10-11pm. Also, the association between bedtime and the risk of developing heart diseases was higher among women.
The team found falling asleep after midnight or before 10 pm both was associated with around a 25 percent increase in risk of cardiovascular disease, compared to falling asleep between 10-11 pm. This increase in risk dropped to 12 percent for those who fell asleep between 11-12 pm.
“The riskiest time was after midnight, potentially because it may reduce the likelihood of seeing morning light, which resets the body clock,” says Plans.
This trend remained when taking into account age, gender, sleep duration, being an early bird or night owl, smoking status, weight, diabetes, blood pressure, cholesterol level, and socioeconomic status. It was also more pronounced for women, but the researchers aren’t yet sure why.
When researchers delved deeper into the results, they found that the link between bedtime and heart disease appears to be stronger in women than men. However, scientists discovered that men who go to bed before 10 p.m. continued to display a higher risk for cardiovascular disease.
“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. The riskiest time was after midnight, potentially because it may reduce the likelihood of seeing morning light, which resets the body clock,” Dr. Plans reports.
This sort of study can’t determine if sleep timing itself contributes to heart disease – it may be other behaviors linked to staying up late, like staying out drinking or stress keeping people awake that are causing the problems.
The study was also limited by age, socioeconomics and ethnicity – predominantly wealthier white people between 43 to 79 years old – so may not necessarily hold true for other demographics.
However, the use of biometric data eliminates potential recall biases that could be present in studies relying on survey data.
What’s more, results align with previous research showing increased risk of cardiovascular problems for people with delayed bedtimes, and with what we understand about the physiology of our body clock: that it needs a regular timed reboot.