- A new study focuses on the health impacts of being more active in the evening and going to bed later. In other words, a ‘night owl.’
- Focusing on heart health, the authors conclude that, compared with non-night owls, they have an increased risk of cardiovascular disease.
- The authors also drill down into the lifestyle factors that drive this increase in risk.
Cardiovascular diseases are still the leading cause of death globally. The size of this issue ensures that research into its causes and treatments continues at pace.
The latest study to investigate the factors involved in heart disease investigated the role of chronotypes.
The researchers compared people who are more active and alert in the evening (night owls) with those who are most active and alert in the mornings (larks) and those who are somewhere in the middle (intermediates).
Over an average of 14 years of follow-up, they found that night owls’ risk of experiencing a heart attack or stroke was 16% higher than those in the intermediate category.
In 2022, the American Heart Association updated its Life’s Simple 7, a list of measures for improving and maintaining heart health. They added “
The addition of sleep was based on decades of research demonstrating that good quality sleep is vital for long-term heart health.
Life’s Essential 8 are:
In the new study, the researchers wanted to understand whether there were links between individuals’ chronotypes and risk factors for cardiovascular disease, as measured by Life’s Essential 8.
They theorized that being a night owl may be a “marker for underlying circadian misalignments,” meaning a disrupted daily wake-sleep cycles.
Earlier work has shown that mismatches between the natural light-dark cycle and an individual’s body clock are associated with cardiometabolic issues. This is one of the reasons why shift workers are at an
The authors also explain that individuals with misaligned body clocks might experience disruptions in their brain’s reward pathways. This could increase the likelihood of smoking, drinking alcohol in excess, and less healthy food choices.
In addition, previous research has shown that night owls and individuals with misaligned circadian rhythms are
The researchers wanted to test their theory that night owls are more likely to have a poorer heart health profile (lower Life’s Essential 8 scores), which would increase their cardiovascular risk.
To investigate, they took data from the UK Biobank, a long-term study carried out in the United Kingdom. Their analysis included records from 322,777 adults aged 39–74 without known cardiovascular disease at the start of the study.
Each participant completed questionnaires, and their chronotype was assessed using their answer to the following question: “Do you consider yourself to be? Definitely a ‘morning’ person; More a ‘morning’ than ‘evening’ person; More an ‘evening’ than a ‘morning’ person; Definitely an ‘evening’ person; Do not know; Prefer not to answer.”
The scientists also had access to information that allowed them to score participants on each of Life’s Essential 8 factors out of 100. They also combined the scores from each factor to create a composite score out of 100.
These individuals were then followed up for an average of 14 years, and any cardiovascular events were recorded.
The researchers’ analysis, as predicted, found that individuals who self-reported as night owls were at an increased risk of cardiovascular disease.
Around two-thirds of participants had an intermediate chronotype, and 8% reported a “definitely evening” chronotype. Compared with “intermediates,” those with a “definitely evening” chronotype were younger, had a lower socioeconomic status, and were more likely to be more highly educated.
Being a night owl was also associated with having a lower overall Life’s Essential 8 score. Specifically, compared with intermediates, “night owls had a 79% higher prevalence of an overall poorer [Life’s Essential 8] score.“
In contrast, being a lark was linked to a slightly better Life’s Essential 8 score than intermediates.
When looking at health outcomes, the scientists found that being a night owl was associated with a 16% greater risk of heart attack or stroke during follow-up, compared with those in the intermediate group.
Medical News Today spoke to Raj Dasgupta, MD chief medical advisor for Sleepopolis, who was not involved in the study, about these findings. Dasgupta put this figure into perspective:
“A 16% higher relative risk is modest at the individual level, but meaningful at the population level. It is similar in size to other lifestyle-associated risk factors we take seriously in preventive care.”
Interestingly, larks had a 5% lower prevalence of poor Life’s Essential 8 scores than intermediates or night owls.
“Overall, these results are not surprising,” Dasgupta told MNT when askedwhether these findings were in line with previous research. “Previous research strongly links delayed sleep phase disorder and general irregular sleep patterns to higher cardiovascular disease risk.”
William Lu, MD, a sleep medicine practitioner and medical director for Dreem Health, a digital sleep clinic, likewise not involved in the study, also told us that: “The unexpected key takeaway isn’t that evening chronotypes face elevated cardiovascular risk, but rather the link between night owls and increased susceptibility to circadian misalignment.”
“This misalignment,” Lu continued, “appears to be the true source of risk, as it encourages less physical activity, greater nicotine exposure, and higher blood pressure.”
Overall, the picture seems quite bleak for those of us who tend to stay up later into the night. However, there is a silver lining.
Kristen Knutson, PhD, associate professor of neurology and preventive medicine at Feinberg School of Medicine in Chicago, IL, who was not involved in the study, explained in a press release that “these findings show that the higher heart disease risks among evening types are partly due to modifiable behaviors such as smoking and sleep.”
This, she detailed, means that “evening types have options to improve their cardiovascular health.“ Night owls are not “inherently less healthy, but they face challenges that make it particularly important for them to maintain a healthy lifestyle.”
In agreement, John La Puma, MD, a board-certified internist who was not involved in the study, told MNT that, “three-quarters of the cardiovascular risk from being a night owl is explained by the Life’s Essential 8 metrics.”
This, he explained, means that it’s not a “biological death sentence” but rather a “modifiable driver of unhealthy behaviors.”
“These people need targeted interventions for sleep hygiene, physical activity, diet, and nicotine,” La Puma concluded.
Along these lines, Dasgupta told us that “being a night owl itself was not the main problem; the downstream habits that often come with an evening chronotype were.”
MNT asked the experts quoted above to provide advice to any night owls reading this. “First of all, don’t tell patients to have more willpower,” cautioned La Puma.
“It’s their environment that’s broken and working against their biology. The primary clinical intervention should be circadian alignment. They need 15 minutes of morning light with at least 10,000 lux without sunglasses and not through a window.”
– John La Puma, MD
This, he explained, will help readjust their biological clock and “encourage deep sleep.” He also recommended keeping physically activity, preferably outdoors.
“I would not tell them to suddenly become a morning person,” Dasgupta suggested. “Instead, I would focus on the basics. Prioritize consistent sleep timing and sleep duration, avoid nicotine, time meals well, and exercise earlier in the day when possible.”