You’ve heard the phrase “the early bird gets the worm.” New research suggests the early bird may also enjoy a lower risk of heart disease. A study found that self-described “night owls” have a higher risk of heart disease and other negative cardiovascular outcomes than people who prefer earlier bed and wake times.
Over about 14 years, researchers followed nearly 323,000 adults aged 39 to 74 who were initially free of known cardiovascular disease. Participants reported their usual sleep–wake patterns and were scored on how closely they followed the Life Essential Eight (LE8) measures for heart health: balanced diet, regular physical activity, low nicotine exposure, quality sleep, appropriate body mass index, healthy blood lipids, blood glucose, and blood pressure. Higher scores meant better adherence.
After an average of 14 years, the researchers looked at who had experienced a heart attack or stroke and compared those events with each person’s LE8 score and sleep preference. Self-proclaimed night owls with lower LE8 scores were the most affected, leading the team to conclude that night owls had a 16% higher risk of heart attack or stroke than definite morning types or people with an intermediate sleep–wake preference.
The extra risk for night owls appeared to be driven largely by lifestyle factors: poorer diet, higher nicotine use, shorter or poorer-quality sleep, less frequent exercise, higher body weight, and unmanaged blood sugar.
However, “when these risk factors were accounted for statistically, the excess cardiovascular risk associated with being a night owl was largely eliminated,” says cardiologist Dr Allen Taylor. In other words, the study shows an association rather than proving that staying up late directly causes heart disease. Even so, the findings underline that sleep timing sits alongside diet, movement, and other habits as a key pillar of heart health.
How sleep affects heart health
Each person’s circadian rhythm runs on its own schedule, but the brain still relies heavily on light cues to release the hormones that drive waking and sleeping. Most people feel sleepy as it gets dark and more alert with daylight, so pushing against that natural pattern can chip away at overall health.
“Sleep supports cardiovascular health through physiological changes in heart rate and blood pressure,” says sleep scientist Carleara Weiss.
“Adequate sleep duration and quality also regulate immune function and hormone levels and reduce inflammatory response,” Weiss adds. “Oxygen saturation is another important aspect of sleep, and cardiovascular health is negatively impacted in people with untreated obstructive sleep apnoea.”
Sleep also influences the hormones ghrelin, which signals hunger, and leptin, which signals fullness, she explains. When sleep is short or broken, ghrelin can rise and leptin can fall, driving cravings for high-fat, highly processed foods. Over time that can promote weight gain and raise the risk of heart problems.
How to get better sleep
“Behavioural changes are often the first step in readjusting sleep and circadian rhythms,” says Weiss. That can include gradually shifting bedtime and wake time, limiting bright light at night and using morning light exposure to cue the body to wake up.
Improving other Life Essential Eight factors such as diet, movement and nicotine exposure also tends to support more consistent sleep, notes Dr Taylor. It is all connected.
Some people, including night shift workers and those with delayed sleep phase syndrome, may need extra support. In those cases, Weiss recommends speaking with a health professional about strategies or treatments that protect sleep quality.
The bottom line
By building heart healthy habits like prioritising good quality sleep, eating a nutrient dense diet and managing stress, the extra risk seen in night owls “can be substantially reduced or eliminated,” says Dr Taylor. In practical terms, keeping up healthy routines and protecting sleep matters more than the exact time you turn the lights out.
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