While many uncontrollable factors like genetics can affect heart health, about 80% of all cases of cardiovascular disease are preventable through lifestyle. Steps like quitting smoking, exercising your body regularly, and loading up on foods high in fiber can lower your risk of heart disease.
And new research published this week in the European Heart Journal – Digital Health suggests that there is another simple, but potentially powerful, lifestyle change that can help: going to bed at a specific time.
People who fall asleep between 10 p.m. and 11 p.m. have a lower risk of developing cardiovascular disease than people who fall asleep either before or after this time window.
“The body has an internal 24-hour clock called a circadian rhythm that helps regulate physical and mental functioning,” study author David Plans, research director at UK health technology company Huma, said in a statement.
“Although we cannot conclude causality from our study,” added Plans, “the results suggest that going to bed early or late can be more likely to disrupt the internal clock, with negative consequences for cardiovascular health.”
The power of circadian rhythms
Plans and his team analyzed data from more than 88,000 participants from the UK Biobank, a huge database of health and lifestyle data available for research. Participants answered questions about their daily health habits and wore a device that logged both falling asleep at night and waking up in the morning. The average age of the study participants was 61 years, of which around 60% were women.
Overall, the researchers found that people who fell asleep at midnight or later had a 25% higher risk of developing cardiovascular disease than those who fell asleep between 10:00 pm and 11:00 pm% higher risk . And those who fell asleep before 10 p.m. had a 24% increased risk.
The researchers did what they could to control other factors known to increase a person’s risk for heart disease, such as smoking, high blood pressure, and socioeconomic status. They found that the link between bedtime and heart health was still there.
While the new study fails to determine cause and effect, the researchers believe their results have a lot to do with a person’s natural circadian rhythm – the inner 24-hour sleep clock, which is closely tied to the sun’s light-dark cycle is. If this internal clock is disrupted by going to bed early or late, it can have a negative impact on the heart, the researchers believe.
This is certainly not the first hypothesis of its kind. Circadian rhythms are known to affect many body systems, and previous research has shown that people with atypical bedtime – especially the millions of Americans who work shifts – are at greater risk of developing heart disease. Yes, working outside of work can make it much more difficult for people to exercise or eat nutritious meals. However, it is believed that shift work also affects people’s underlying biological systems.
“Our study shows that the optimal time to fall asleep is at a certain point in the body’s 24-hour cycle, and deviations can be harmful to your health,” said Plans. (Plans and its co-researchers announced that their study was funded by Huma, but the company played no role in the data collection or analysis.)
Another argument for prioritizing sleep
While the researchers who conducted the new study indicated that more work needs to be done to understand the possible link between bedtime and heart health, they believe their research provides strong clues.
“If our results are confirmed in other studies, sleep timing and basic sleep hygiene could be a cost-effective public health goal to lower the risk of heart disease,” Plans said.
Of course, people don’t necessarily have complete control over their bedtimes, especially those whose jobs require working late at night or very early in the morning.
But as much as possible, sleep experts say you should be reasonably consistent in falling asleep and waking up – and aiming for a bedtime that means you can get at least seven to eight hours of sleep. Also, avoid large meals and caffeine before bed, and try to create a quiet, dark sleeping environment.
As more and more research shows, doing whatever it takes to prioritize a good night’s sleep isn’t just good for you the next day. It can make a huge difference to your overall health in the long run.
This article originally appeared on HuffPost and has been updated.