A new study finds that adults who tend to stay up late (night owls) score lower on cardiovascular health assessments and face a higher risk of heart attack or stroke. The study, published in the journal of the American Heart Association, investigated how a person's temporal pattern—their natural tendency to be active in the morning or evening—is linked to overall heart health. Researchers drew on data from the UK Biobank over 14 years, which included about 300,000 adults with an average age of 57. Approximately 8% of participants identified as 'definite evening types,' meaning they go to bed very late. Another 24% called themselves 'definite morning types,' tending to wake up and go to bed early. The largest group, the 'intermediate' group, which made up 67% of participants, did not identify with either group. Each person's heart health was assessed using the American Heart Association's 'Life's Simple 7' index. This index is a comprehensive assessment that includes: physical activity level, diet, blood pressure, cholesterol level, nicotine use, sleep patterns, weight management, and blood sugar level. Researchers also studied the rate of heart attacks and strokes during the follow-up period. This association was more pronounced in women than in men. Dr. Sina Kianersi, the lead researcher and a fellow at Harvard Medical School, said: 'People who prefer to stay up late often suffer from circadian rhythm disruption, which means their internal body clock may not align with the natural light-dark cycle or their usual daily schedules.' She explained that such individuals 'may be more prone to behaviors that can affect cardiovascular health, such as poor diet, smoking, and inadequate or irregular sleep.'
