‘Night owls’ may have worse heart health — but why?

February 8, 2026

Some people hit their stride in the morning, while others feel most awake and productive at night. But a growing body of evidence suggests that being part of the latter group, the “night owls,” could be linked to poorer heart health.

Now, a large study published Jan. 28 in the Journal of the American Heart Association adds weight to the idea.

Pulling from the UK Biobank, a massive repository of data from U.K. adults, researchers followed more than 322,000 adults ages 39 to 74 for nearly 14 years. They examined how “chronotype” — whether someone is a morning or evening person — relates to their cardiovascular disease risk. LIVESCIENCE