People who prefer staying up late may be putting their heart health at risk, with new research suggesting a clear link between late bedtimes and heart disease risk, particularly among women in midlife and older age.
An analysis cited by the American Heart Association has found that adults who are most active in the evening tend to have poorer cardiovascular health than those who follow earlier sleep and activity patterns. The findings are based on data from more than 300,000 adults enrolled in the UK Biobank, with an average age of about 57 years.
Researchers examined participants’ chronotypes, which describe natural sleep and wake preferences. About eight per cent of those studied identified as “definitely evening people,” meaning they went to bed very late and were most active later in the day. This group recorded significantly lower scores on the American Heart Association’s Life’s Essential 8 measure, a framework that assesses heart health using factors such as diet, physical activity, sleep, smoking, body weight, blood sugar, cholesterol, and blood pressure.
Compared to people without a strong morning or evening preference, night owls were far more likely to fall into the poor cardiovascular health category. They also showed a higher risk of heart attack or stroke during a follow-up period of around 14 years. The association between late bedtimes and heart disease risk appeared to be stronger among women than men.
The study suggests that lifestyle habits explain much of this increased risk. Evening types were more likely to report inadequate or irregular sleep, lower-quality diets, and higher rates of smoking. These behaviours, researchers said, play a major role in lowering heart health scores among night owls.
Lead author Sina Kianersi noted that people who stay up late often experience a mismatch between their internal body clock and daily schedules. This circadian misalignment can make it harder to maintain routines that support long-term heart health, ScienceDaily reported.
Experts say the findings also point to a clear opportunity for prevention. Improving sleep quality, quitting smoking, and adopting healthier eating habits could help reduce cardiovascular risk, even for those who naturally prefer late nights. Specialists stress that night owls are not inherently unhealthy, but they may face greater challenges in maintaining heart-friendly lifestyles.
The researchers acknowledged some limitations, including the fact that most participants were white and generally healthier than the broader population. Chronotype was also assessed only once and relied on self-reported information. Even so, the study adds to growing evidence that when people sleep may be an important factor in long-term heart health.
