Why Your Bedtime Could Affect Your Heart Health
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Introduction
We all know that sleep is important for our health. But did you know that when you go to sleep might also matter for your heart? A new study from the UK Biobank shows that going to bed at the “wrong” time could increase your risk of heart disease—especially for women.
The Study
This study used data from over 88,000 people in the UK who wore wrist-worn activity trackers (accelerometers) for a week. These devices measured sleep patterns without relying on memory or sleep diaries. The researchers then followed these people for about 6 years to see who developed cardiovascular disease (CVD), including conditions like heart attacks and strokes.
What They Found
The safest time to fall asleep seemed to be between 10:00 p.m. and 10:59 p.m. People who fell asleep earlier or later than that had a higher risk of heart problems.
Here’s what the study found:
- People who fell asleep after midnight had a 25% higher risk of heart disease.
- Those who went to bed between 11:00 p.m. and 11:59 p.m. had a 12% higher risk.
- Even people who went to bed before 10:00 p.m. had a 24% higher risk.
- These risks remained even after accounting for sleep length, irregular sleep, smoking, weight, and other common heart risk factors.
Women at Higher Risk
One surprising result was that the connection between sleep timing and heart disease was stronger for women. In women, both very late (after midnight) and very early bedtimes (before 10:00 p.m.) were linked to higher heart disease risk. In men, only early bedtimes showed a significant risk.
Why Does Timing Matter?
Our bodies follow a natural rhythm called the “circadian rhythm,” which acts like an internal clock. Sleeping too early or too late may disturb this rhythm and affect heart function. The study didn’t prove that odd sleep times cause heart disease, but it strongly suggests a link.
The Role of Technology
This research also shows how useful wearable devices can be in tracking health. Instead of relying on memory or self-reported surveys, data from wrist trackers provided accurate and real-time sleep information. This makes it easier to study how lifestyle habits affect long-term health.
What You Can Do
To protect your heart, aim to fall asleep between 10:00 p.m. and 11:00 p.m. Try to:
- Keep a regular sleep schedule, even on weekends
- Avoid screens and heavy meals before bed
- Create a calming bedtime routine
Conclusion
Going to bed at the right time could be a simple but powerful way to reduce your risk of heart disease—especially if you're a woman. While more research is needed, this study gives us another reason to prioritize healthy sleep habits.