Doctors have long warned about high blood pressure, smoking, and not getting enough exercise. But now there is a lot of evidence that the exact time you turn off the light and go to sleep could also be a risk factor.
When going to bed puts your heart at risk
A big study in the UK found that the time you go to bed is linked to your risk of getting heart disease, including stroke. The European Heart Journal published the study, which followed more than 88,000 adults for a number of years.
The risk goes up a lot after midnight
The scientists looked at each bedtime category and compared it to the time frame of 10:00–10:59 pm. The differences were very clear: Going to bed after midnight raises your risk of heart disease by about 25%. Going to bed between 11:00 and 11:59 pm: about 12% more likely. Going to bed before 10:00 p.m. raises the risk by about 24%.
It seemed that the most dangerous time to fall asleep was after midnight
It looked like the most dangerous time to fall asleep was after midnight, when the risk went up by about a quarter. One thing that stood out was that the pattern was different for men and women.
It looks like women have to pay more
The heightened risk was significantly more pronounced in women. The researchers think that differences in the endocrine system, which is a complex network of hormones, may be to blame. These hormones work closely with the circadian rhythm, the body’s internal clock that tells it when to sleep, eat, and release certain hormones.
Why the clock matters to the body
The study did not definitively establish a direct causal link between late bedtimes and strokes; however, it strongly indicates that misaligned sleep schedules may adversely affect cardiovascular health over time.
How this stacks up against traditional stroke risk factors
A stroke doesn’t usually have just one cause. It usually happens when a lot of risks build up over time. The same old suspects are still in charge: High blood pressure, cigarettes, cholesterol levels that are too high, diabetes type 2, not enough physical activity, a lot of drinking, stress that lasts a long time, and being overweight.
What this means for when you go to bed
Aligning your sleep between 10:00 and 11:00 pm seems like a pretty easy way to help your heart and brain stay healthy. Every week, move your bedtime up by 15 to 20 minutes until you regularly fall asleep before 11:00 p.m.
Knowing some important words
AVC is short for “accident vasculaire cérébral,” which is French for “stroke.” It happens when a clot blocks blood flow to a part of the brain or when a blood vessel in the brain bursts.
Your body’s internal clock is the circadian rhythm. It affects when you get sleepy, when your body temperature goes up or down, how well you digest food, and even when your heart beats a little faster.
Two things that happen every day that change your risk
Imagine two people in their late 50s. Both of them have high blood pressure and a job that stresses them out. The first person usually falls asleep at 10:30 pm, wakes up at 6:30 am, and takes a short walk outside before going to work. The second goes to bed at 12:30 or 1:00 am most nights, wakes up groggy at 7:00 am, and rushes to a desk right away. The only thing that makes them different is how their daily rhythm fits with their biology.
