Night Owls Face 16 Percent Higher Risk of Heart Attack and Stroke
Finn's Take· TL;DR- Evening chronotypes face 16% higher heart attack and stroke risk due to modifiable behaviors like smoking and poor diet.
- Night owls show worse scores across six of eight cardiovascular health factors, with circadian misalignment contributing to unhealthy lifestyle choices.
- Lifestyle modifications targeting smoking, sleep quality, and diet can significantly reduce cardiovascular disease risk regardless of natural sleep preference.
Massive Study Reveals Troubling Heart Risks for Late Sleepers
A groundbreaking study analyzing data from more than 320,000 adults has uncovered a stark reality for night owls: those who identify as "evening types" face a 16% higher risk of heart attack and stroke compared to people with more typical sleep schedules. The research, published in the Journal of the American Heart Association, represents one of the largest investigations into how sleep timing affects cardiovascular health.
The study examined survey and biometric data from British adults aged 39 to 74 who had not experienced heart attacks or strokes at baseline . Participants were asked to categorize themselves as "definite morning," "definite evening," or "intermediate" people. What researchers discovered was alarming: night owls showed a 79% higher prevalence of overall poor cardiovascular health scores using the American Heart Association's Life's Essential 8 metric.
The implications extend far beyond simple sleep preferences. Evening chronotype was more strongly related to low cardiovascular health scores in women than in men , suggesting gender-specific vulnerabilities that warrant closer attention from healthcare providers.
The Hidden Culprits Behind the Risk
The increased cardiovascular danger isn't inherently tied to staying up late itself. Instead, unhealthy behaviors among night owls, such as poor diet quality, insufficient sleep and smoking, may account for their lower cardiovascular health profile . Nicotine use alone accounted for 34 percent of the link between being a night owl and cardiovascular disease .
Night owls had worse scores in six out of the eight risk factors that make up Life's Essential 8 , which measures diet quality, physical activity, nicotine exposure, sleep health, body mass index, cholesterol levels, blood sugar, and blood pressure. This comprehensive deterioration in multiple health markers paints a concerning picture of how evening preferences cascade into broader health challenges.
Lead study author Sina Kianersi explains that "evening people often experience circadian misalignment, meaning their internal body clock may not match the natural day-to-night light cycle or their typical daily schedules" . This fundamental mismatch creates a perfect storm of health-compromising behaviors.
Hope for Change
The research offers encouraging news despite its sobering findings. "These findings show that the higher heart disease risks among evening types are partly due to modifiable behaviors such as smoking and sleep. Therefore, evening types have options to improve their cardiovascular health," notes Dr. Kristen Knutson, volunteer chair of the 2025 American Heart Association statement on circadian health.
The study suggests that it is the risk factors associated with being a night owl, not when you go to bed, that drive poorer cardiovascular outcomes . This distinction is crucial because it shifts focus from unchangeable sleep preferences to actionable lifestyle modifications.
For contrast, "morning people" had a 5% lower prevalence of low heart health scores compared with those without a strong morning or evening chronotype , demonstrating that early risers enjoy measurable cardiovascular advantages.
Practical Steps Forward
As Stanford Medicine's Dr. Eleanor Levin points out, "We can't change the circadian rhythm, because it is intrinsic and not really changeable. Instead, we can concentrate on these modifiable risk factors" . This perspective transforms a seemingly hopeless situation into an actionable health strategy.
The research underscores that night owls aren't destined for poor health outcomes. Study leader Sina Kianersi emphasizes, "It is not like night owls are doomed" . The key lies in recognizing heightened vulnerability and taking proactive steps to address the lifestyle factors that compound cardiovascular risk.
This study arrives at a time when millions of people work non-traditional hours or naturally prefer evening activity. Understanding these risks empowers individuals to make informed decisions about smoking cessation, sleep hygiene, diet quality, and physical activity—choices that could significantly reduce their elevated cardiovascular risk regardless of their natural sleep preferences.