Many people see themselves as night owls. They feel more alert in the evening, enjoy staying up late, and often struggle with early mornings.
While this schedule may feel natural, new research suggests it could come with hidden risks for heart health.
A large study has found that people who are most active late at night tend to have poorer heart health than those who follow more typical daily schedules.
The study shows that the problem is not being a night owl itself, but the conflict between a person’s natural body clock and the way modern society is structured.
The research was led by Sina Kianersi, a research fellow at Brigham and Women’s Hospital and Harvard Medical School. He explained that night owls are not destined to have heart disease.
Instead, the real issue is that their internal clock does not match common work and social schedules. This mismatch can make it harder to maintain healthy habits that protect the heart.
Heart disease remains the leading cause of death in the United States. To reduce this risk, the American Heart Association highlights eight important areas of heart health. These include being physically active, avoiding smoking, eating a healthy diet, getting enough sleep, and keeping blood pressure, cholesterol, blood sugar, and body weight under control.
So how does being a night owl fit into this picture? The answer lies in the body’s circadian rhythm. This is the internal clock that follows a roughly 24-hour cycle. It helps control sleep and wake times, but it also affects heart rate, blood pressure, hormone release, digestion, and how the body uses energy.
Everyone’s circadian rhythm is slightly different. Some people naturally wake up early and feel best during the morning. Others feel more focused and energetic later in the day and evening. These differences are normal. However, problems arise when a person’s natural rhythm does not match daily demands like early work hours or fixed meal times.
To better understand the health effects of being a night owl, the researchers studied data from more than 300,000 middle-aged and older adults who took part in the UK Biobank, a large health database. Participants reported whether they considered themselves night owls, early birds, or somewhere in between.
About eight percent of participants identified as night owls. Around a quarter were early birds, and the rest fell in the middle. The researchers followed these people for about 14 years to track heart-related health outcomes.
During that time, night owls were found to have a 16 percent higher risk of having their first heart attack or stroke compared with people who had average sleep-wake patterns. Night owls also scored worse on overall heart health measures, especially women.
The study suggests that unhealthy habits play a major role in this increased risk. Night owls were more likely to smoke, sleep too little, and eat poorly. These behaviors are known to harm heart health and may develop because night owls are forced to live on schedules that do not suit their biology.
Kristen Knutson, a sleep expert from Northwestern University who was not involved in the study, explained that night owls often have to wake up early for work even though their bodies are not ready.
This can affect more than just sleep. The body’s ability to process food changes throughout the day. Eating large or unhealthy meals early in the morning or late at night may be harder for a night owl’s body to handle.
Late-night schedules can also limit access to healthy food options, leading people to choose processed or fast foods. Over time, these patterns can raise blood sugar, cholesterol, and body weight, all of which increase heart disease risk.
Even if night owls cannot fully change their natural rhythm, experts say there are ways to reduce the risks. Keeping regular sleep and wake times, aiming for enough sleep, and focusing on basic healthy habits can make a real difference. Quitting smoking is especially important and offers strong protection for heart health.
When reviewing the findings, the study does not prove that staying up late directly causes heart disease. Instead, it shows a strong link between late-night patterns, unhealthy behaviors, and poorer heart health. The results highlight how modern schedules may work against some people’s biology and make healthy living more difficult.
Overall, the study suggests that night owls should not blame themselves, but they should be more aware of the risks. By paying attention to sleep routines, diet, physical activity, and smoking, night owls can still protect their hearts and improve their long-term health.
If you care about heart health, please read studies about how eating eggs can help reduce heart disease risk, and Vitamin K2 could help reduce heart disease risk.
For more information about heart health, please see recent studies about how to remove plaques that cause heart attacks, and results showing a new way to prevent heart attacks, strokes.
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