Beyond the Midnight Oil: Why Being a ‘Night Owl’ May Raise Heart Attack and Stroke Risk

Published: February 3, 2026

The quiet of the late-night hours may offer productivity for some, but a growing body of evidence suggests it might come at a cost to the heart. A comprehensive study published recently in the Journal of the American Heart Association reveals that individuals who identify as “night owls”—those who are most active in the evening and go to bed late—face a significantly higher risk of cardiovascular events, including heart attacks and strokes, compared to their early-rising counterparts.

According to the World Health Organization (WHO), cardiovascular diseases (CVDs) remain the leading cause of global mortality, claiming an estimated 19.8 million lives in 2022. Of these deaths, approximately 85% were attributed to heart attacks and strokes. While diet and exercise are well-known pillars of heart health, this new research highlights how our internal biological clocks, or chronotypes, play a secondary but vital role in our long-term wellness.

Decoding the Chronotype: Morning Larks vs. Night Owls

Every person has a “chronotype,” a term used by sleep scientists to describe the natural inclination of the body to sleep at a certain time. Researchers for this study categorized participants into three groups:

1. Morning Larks: Those most active in the early hours.

2. Intermediates: People who fall somewhere in the middle.

3. Night Owls: Those who thrive in the evening and stay up late.

Using data from the UK Biobank, researchers followed 322,777 adults (aged 39–74) who had no history of heart disease. Over a 14-year follow-up period, the team analyzed the relationship between these sleep-wake patterns and “Life’s Essential 8″—the American Heart Association’s (AHA) checklist for lifelong heart health.

The Findings: A 79% Higher Risk

The results were stark. Night owls had a 79% higher risk of poor cardiovascular health compared to the intermediate group. Furthermore, night owls showed significantly lower scores in six out of the eight key cardiovascular health markers, including blood pressure, blood sugar management, and nicotine exposure.

The “Circadian Misalignment” Factor

Why does staying up late impact the heart? The researchers theorize that being a night owl serves as a marker for circadian misalignment. This occurs when a person’s internal body clock is out of sync with the natural light-dark cycle of the environment.

This misalignment is similar to what shift workers experience. When the body is forced to be awake when it should be resting—or eating when its metabolism is naturally slowed—it can lead to “cardiometabolic stress.” This stress contributes to inflammation, higher blood pressure, and impaired glucose processing.

“The key point is not that chronotype is ‘good’ or ‘bad,’ but that being a ‘night owl’ often travels with a less favorable heart-health profile,” explains Dr. Sina Kianersi, a postdoctoral research fellow at Brigham and Women’s Hospital/Harvard Medical School and the study’s lead author.

Behavior, Not Just Biology

Crucially, the study suggests that the increased risk isn’t necessarily a “genetic curse” of being a late riser. Instead, it is often driven by the lifestyle behaviors that tend to cluster around the night owl chronotype.

Night owls were found to be more likely to:

• Use nicotine products.

• Engage in less physical activity.

• Have less consistent sleep patterns.

• Maintain a less nutritious diet.

“For individual risk, the biggest drivers are still the basics,” Dr. Kianersi noted. This means that while a late schedule might be the trigger, the cause of the heart risk is often the secondary habits—like late-night snacking or sedentary behavior—that come with it.

Expert Perspective

Independent experts agree that while the study is robust, it highlights the difficulty of living in a “morning-oriented” world.

“Our society is largely built around a 9-to-5 schedule,” says Dr. Elena Rossi, a cardiologist not involved in the study. “When a natural night owl is forced to wake up early for work, they suffer from ‘social jetlag.’ They are sleep-deprived during the week and try to catch up on weekends, which creates a ‘yo-yo’ effect on the cardiovascular system.”

How to Protect Your Heart (Even if You Hate Mornings)

If you are a confirmed night owl, the news isn’t all bad. Because the risk is largely tied to modifiable behaviors, you can take specific steps to bridge the gap:

• Prioritize Consistency: Try to go to bed and wake up at the same time every day, even on weekends.

• Seek Morning Light: Exposure to natural sunlight shortly after waking helps reset your internal clock and can improve nighttime sleep quality.

• Monitor the ‘Essential 8’: Stay on top of your “numbers”—specifically blood pressure, cholesterol, and blood sugar.

• Physical Activity: Aim for at least 150 minutes of moderate-intensity exercise per week.

• Avoid Late-Night Stimulants: Limit caffeine and nicotine in the evening hours to reduce the strain on your heart.

Limitations and Future Research

While the study size is impressive, researchers acknowledge some limitations. The data is based on self-reported sleep preferences, which can change over time. Additionally, the UK Biobank population is primarily of European descent, meaning further research is needed to see if these findings apply equally across all ethnic and global populations.

As we continue to learn more about the “medicine of sleep,” it is becoming clear that when we sleep may be just as vital as how long we sleep.

Reference Section

• https://www.ndtv.com/health/staying-up-late-may-increase-your-heart-attack-and-stroke-risk-heres-how-10930288

Medical Disclaimer: This article is for informational purposes only and should not be considered medical advice. Always consult with qualified healthcare professionals before making any health-related decisions or changes to your treatment plan. The information presented here is based on current research and expert opinions, which may evolve as new evidence emerges.