Night Owls Could Be Putting Their Heart Health at Risk

New research links late nights and low cardiovascular health scores

7:00 AM CST on February 25, 2026

Illustration of a man and woman standing on either side of a large clock, with day and night backgrounds behind them. Credit: mentalmind / Shutterstock.

Are you a night owl or an early bird?

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If it’s the former, then I’m afraid I’ve got some bad news. People who stay up late have worse cardiovascular health than people who wake up early, according to a new study published in the Journal of the American Heart Association.

Researchers from Harvard Medical School followed the health of more than 300,000 adults over a 14-year period and determined self-described night owls had poorer cardiovascular outcomes as measured by the American Heart Association’s Life’s Essential 8 metrics. These metrics include eating a healthy diet, exercising regularly, getting restful sleep, and not smoking, as well as maintaining healthy weight, blood pressure, blood sugar, and cholesterol levels.

“‘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,” lead study author Sina Kianersi said in a statement.

Read more: “How Your Body Knows What Time It Is”

Researchers found that those who stay up later had a 79 percent higher prevalence of having a poor cardiovascular health score and a 16 percent higher risk of having a heart attack or stroke, while those who wake up early had a 5 percent lower prevalence of low heart health scores. There were sex differences, too, with female night owls more likely to have lower health scores than male night owls.

But there is a silver lining for the late-night warriors hidden in this data—75 percent of the adverse scores can be erased by changing behaviors.

“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,” Kianersi said. “Evening types aren’t inherently less healthy, but they face challenges that make it particularly important for them to maintain a healthy lifestyle.”

While our biological clocks are innate, they’re not immutable. They can change naturally over the course of our lives, and we can alter our behavior to change them. So if you’re a night owl interested in shifting to early bird mode, here are some tips on how to get better sleep.

After all, as every night owl knows, there’s no such thing as “too late.”