Research indicates that adults in midlife and older age who are more active during the evening, particularly women, exhibit poorer heart health compared to those without a strong preference for morning or evening activities. This insight comes from the American Heart Association's Life's Essential 8 measure.
Analyzing data from the UK Biobank, researchers found that typical habits of night owls--such as lower-quality diets, insufficient sleep, and higher smoking rates--contribute to their diminished cardiovascular health scores.
The study highlights a significant opportunity for improvement; enhancing daily habits like sleep quality, nutrition, and quitting smoking could potentially lower the risk of heart attacks and strokes for those who identify as night owls.
Evening Activity and Heart Health
Individuals who are more active later in the day were found to have worse cardiovascular health than early risers. The study, published in the Journal of the American Heart Association, emphasizes the importance of daily activity timing on long-term heart health.
Examining Sleep Patterns in a Large Population
The research evaluated health data from over 300,000 adults, with an average age of around 57 years, who were part of the UK Biobank. The focus was on chronotypes, which indicate a person's natural sleep and wake preferences and their correlation with heart health.
Participants categorized themselves based on their daily routines. Approximately 8% identified as "definitely evening people," going to bed late (e.g., 2 a.m.) and being most active later in the day. Around 24% were "definitely morning people," who tended to wake up and sleep earlier (e.g., 9 p.m.) and be active during the day. The remaining 67% were considered to have an "intermediate" chronotype.
Cardiovascular health was assessed using the American Heart Association's Life's Essential 8™ metrics, which evaluate lifestyle factors known to support heart health, including diet, physical activity, smoking habits, and sleep quality.
Comparative Analysis of Chronotypes
Notable differences emerged between night owls and early birds. Compared to those in the intermediate group, evening types had a 79% higher likelihood of poor cardiovascular health scores and a 16% increased risk of heart attack or stroke over a median follow-up of about 14 years. This association was particularly pronounced among women.
Much of the elevated heart disease risk among evening types was associated with lifestyle choices, especially smoking and inadequate sleep. Conversely, morning individuals exhibited a 5% lower rate of poor cardiovascular health compared to those without a strong morning or evening preference.
Understanding the Risks for Evening Types
Lead study author Sina Kianersi, Ph.D., D.V.M., explained that evening types often face circadian misalignment, where their internal clocks do not align with natural light cycles. This misalignment can lead to behaviors detrimental to cardiovascular health, such as poor diet and irregular sleep patterns.
Opportunities for Improvement
Despite the findings, there is hope for those who prefer late nights. Kristen Knutson, Ph.D., FAHA, emphasizes that the heightened heart disease risks among evening types stem partly from modifiable behaviors. Thus, evening types can take proactive steps to enhance their cardiovascular health.
Personalized Approaches to Health
The American Heart Association also suggests considering chronotypes when developing treatment or lifestyle interventions. Some therapies may be more effective when aligned with an individual's circadian rhythms, which vary by chronotype. Tailored programs could assist night owls in adopting healthier lifestyle choices and mitigating their cardiovascular disease risk.
Study Limitations
Researchers acknowledged that the majority of UK Biobank participants were predominantly white and generally healthier than the wider population, which may affect the applicability of the findings. Additionally, chronotype was assessed only once through self-reporting, rather than through repeated measurements.
