Staying up late may raise your heart attack and stroke risk, major new study warns

A large 14-year study finds that night owls face significantly poorer heart health and higher cardiovascular risk compared to early risers.

What happened: A new study published in the Journal of the American Heart Association found that people who stay up late have a significantly higher risk of poor cardiovascular health.

Why it matters now: Cardiovascular disease remains the leading global killer, responsible for 19.8 million deaths in 2022, making early detection of lifestyle-linked risks crucial.

What changes for people: Night owls may need stricter monitoring of heart health factors like blood pressure, sleep, diet, and nicotine exposure.

Who is affected: Adults with late-night sleep patterns, shift workers, and those with irregular circadian rhythms.

New research links late sleeping habits to higher heart disease risk

A major study examining 322,777 adults over nearly 14 years has revealed that people who identify as night owls are at significantly higher risk of cardiovascular issues, including heart attack and stroke.

The research, which analysed chronotypes (your natural sleep-wake preference), found that night owls have a 79 percent higher likelihood of poor cardiovascular health compared to people with intermediate sleep patterns.

Experts say this is not because the chronotype itself is harmful, but because it often aligns with behaviours that damage long-term heart function.

Why night owls face higher heart risks

Researchers found that late sleepers often experience circadian misalignment.

This means their internal biological clock is out of sync with the natural light–dark cycle and with typical daytime routines.

This misalignment can lead to:

disrupted metabolic and hormonal cycles

higher levels of stress hormones

irregular eating patterns

poor sleep quality

reduced daytime physical activity

These factors collectively increase the risk of heart attack, stroke, and other cardiovascular diseases.

Dr Sina Kianersi, the study’s lead author, explained:

“The key point is not that being a night owl is bad, but that it often comes with a less favourable heart-health profile.”

What the study measured

Participants were classified into:

definite morning types

moderate morning types

intermediates

moderate evening types

definite evening types (night owls)

They were then scored using the American Heart Association’s Life’s Essential 8, which includes:

healthy sleep

physical activity

diet

weight

nicotine exposure

cholesterol

blood pressure

blood sugar

Night owls scored worst in six out of eight categories.