Many people naturally prefer staying up late and feel most alert in the evening. These so-called night owls often struggle with early mornings but may feel energetic late into the night.
While this pattern can seem harmless, new research suggests that being most active in the evening may quietly increase the risk of heart disease, especially as people grow older.
The findings also suggest that women who are night owls may be affected more strongly than men.
The study examined how a person’s natural sleep and activity timing, known as chronotype, relates to heart health in midlife and older age. Chronotype reflects whether someone prefers mornings, evenings, or falls somewhere in between.
Researchers analyzed health data from more than 300,000 adults who took part in the UK Biobank, one of the largest long-term health studies in the world. Participants were, on average, about 57 years old when the study began.
People were asked to describe their daily patterns. Some identified as clear morning types who go to bed early, wake up early, and feel most active in the first part of the day.
Others identified as clear evening types who stay up late, wake up later, and reach peak energy in the evening. Most people fell into a middle group, meaning they did not strongly prefer mornings or evenings.
To measure heart health, researchers used the American Heart Association’s Life’s Essential 8 score. This system looks at eight factors known to influence heart health.
These include eating a balanced diet, being physically active, avoiding smoking, getting enough good-quality sleep, and maintaining healthy levels of body weight, blood pressure, cholesterol, and blood sugar. Together, these factors provide an overall picture of cardiovascular health.
The results showed clear differences between chronotype groups. Adults who identified as evening types were much more likely to have poor overall heart health than those in the middle group.
In fact, night owls were about 79 percent more likely to score poorly on the heart health scale. Over an average follow-up period of about 14 years, they were also 16 percent more likely to experience a heart attack or stroke.
Women appeared to be particularly affected. The link between evening activity and poorer heart health was stronger in women than in men. While the study did not fully explain why this difference exists, researchers believe biological factors combined with social and lifestyle pressures may play a role.
The study also helped explain why night owls tend to have worse heart health. Evening types were more likely to have habits that harm the heart. These included poorer-quality diets, shorter or irregular sleep, and higher rates of smoking. When researchers took these behaviors into account, much of the increased heart risk among night owls could be explained.
In contrast, people who identified as morning types showed slightly better heart health. Early birds were about 5 percent less likely to have poor cardiovascular health compared with people without a strong morning or evening preference. This suggests that earlier daily rhythms may make it easier to maintain heart-healthy habits.
One explanation for these findings involves something called circadian misalignment. This happens when a person’s internal body clock does not match the natural day-night cycle or the demands of daily life, such as work schedules.
Evening types often have to wake up early for responsibilities despite feeling biologically inclined to stay up late. This mismatch can disrupt sleep, hormone regulation, and metabolism, all of which can affect heart health over time.
Importantly, experts say the findings do not mean that night owls are destined to develop heart disease. Many of the factors linked to higher risk are changeable. Improving sleep habits, quitting smoking, and choosing healthier foods could significantly reduce risk, even for people who naturally prefer late nights.
When reviewing and analyzing the study’s findings, the key message is that timing matters, but habits matter more. Being a night owl itself is not the main problem.
The increased risk comes largely from behaviors that tend to accompany late-night patterns in modern society. This means there is a clear opportunity for prevention. By focusing on sleep quality, diet, and smoking cessation, evening types can protect their hearts.
The study also highlights the importance of personalized health care. Treatments and lifestyle advice may work better when they align with a person’s natural body clock. Programs designed specifically for night owls could help them overcome challenges linked to late schedules and reduce long-term heart risks.
The researchers noted some limits to the study. Most participants were white and generally healthier than the broader population, so results may not apply equally to all groups. Chronotype was also measured only once and relied on self-reporting. Even so, the large size of the study and long follow-up make the findings meaningful.
Overall, the research suggests that staying up late may quietly strain the heart over time, especially for women. However, it also offers hope. With thoughtful lifestyle changes and awareness of one’s natural rhythms, night owls can take practical steps to protect their heart health and lower the risk of heart attack and stroke later in life.
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.
Copyright © 2026 Knowridge Science Report. All rights reserved.
