Being a night owl may not be great for your heart but you can do
something about it
[January 28, 2026]
By LAURAN NEERGAARD
WASHINGTON (AP) — Being a night owl can be bad for your heart.
That may sound surprising but a large study found people who are more
active late at night — when most of the population is winding down or
already asleep — have poorer overall heart health than the average
person.
“It is not like, that, night owls are doomed,” said research fellow Sina
Kianersi of Brigham and Women's Hospital and Harvard Medical School, who
led the study. “The challenge is the mismatch between your internal
clock and typical daily schedules ” that makes it harder to follow
heart-healthy behaviors.
And that’s fixable, added Kianersi, who describes himself as “sort of a
night owl” who feels a boost in “my analytical thinking” after about 7
or 8 at night.
Heart disease is the leading cause of death in the U.S. The American
Heart Association has a list of eight key factors that everyone should
heed for better heart health: being more physically active; avoiding
tobacco; getting enough sleep and a healthy diet; and controlling blood
pressure, cholesterol, blood sugar and weight.
Where does being a night owl come in? That has to do with the body's
circadian rhythm, our master biological clock. It follows a roughly
24-hour schedule that regulates not just when we become sleepy and when
we’re more awake but also keeps organ systems in sync, influencing
things like heart rate, blood pressure, stress hormones and metabolism.
Everybody’s circadian rhythm is a little different. Prior research had
suggested night owls might have more health problems, as well as risk
factors like higher rates of smoking and less physical activity, than
people with more typical bedtimes, Kianersi said.
To learn more, Kianersi’s team tracked more than 300,000 middle-age and
older adults in the UK Biobank, a huge health database that includes
information about people’s sleep-wake preferences. About 8% of those
people classified themselves as night owls, more active physically and
mentally in the late afternoon or evening and up past most people’s
bedtime. About a quarter were early-birds, most productive in the
daylight hours and likewise early to bed. The rest were average,
somewhere in the middle.
Over 14 years, the night owls had a 16% higher risk of a first heart
attack or stroke compared to the average population, the researchers
found.
[to top of second column]
|
A person looks out of a window in an apartment building in Kansas
City, Mo., May 3, 2020. (AP Photo/Charlie Riedel, File)
 The night owls, especially women,
also had overall worse cardiovascular health based on meeting the
heart association’s eight key factors, the researchers reported
Wednesday in the Journal of the American Heart Association.
Unhealthy behaviors — smoking, insufficient sleep and poor diet —
appear to be the main reasons.
“It comes down to the problem of a night owl trying to live in a
morning person’s world. They’re getting up early for work because
that’s when their job starts but it may not align with their
internal rhythm,” said Kristen Knutson of Northwestern University,
who led recent heart association guidance on circadian rhythms but
wasn’t involved in the new study.
That affects more than sleep. For example, metabolism fluctuates
throughout the day as the body produces insulin to turn food into
energy. That means it might be harder for a night owl to handle a
high-calorie breakfast eaten very early in the day, during what
normally would still be their biological night, Knutson said. And if
they're out late at night, it can be harder to find healthy food
choices.
As for sleep, even if you can't meet the ideal of at least seven
hours, sticking to a regular bedtime and wake time also may help,
she and Kianersi said.
The study couldn't examine what night owls do when the rest of the
world is asleep. But Kianersi said one of the best steps to protect
heart health — for night owls and anyone — is to quit smoking.
“Focus on the basics, not perfection,” he said, again, advice that’s
good for everyone.
All contents © copyright 2026 Associated Press. All rights reserved
 |
