Are you an early bird or a night owl? Why are scientists moving beyond these groups?

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Are you a night owl who always has trouble adjusting to an early schedule? Good news. Researchers are taking a more nuanced look at sleep patterns and how they affect health and behavior.

Chronotype refers to the time when a person naturally feels most inclined to sleep, wake up, and perform physically and intellectually. Previous studies have linked late-night chronology to poor health outcomes such as heart disease and depression, but not consistently.

A Canadian-led study of more than 27,000 adults in the UK was recently published nature communication Shedding light on who might benefit most from prioritizing sleep, physical activity or socializing – and when.

The study combined extensive brain imaging with computer science and questionnaires, cognitive tests and medical chart reviews.

The problem is that classifying people into just two groups – late risers and early risers – is too simplistic. Le Zhou, lead author of the study and a PhD student in neuroscience at McGill University.

“People always think that night owls have bad health and that early birds have a healthy lifestyle,” he said. “But our study found, actually, the short answer is no.”

Strengths and weaknesses were mapped out.

Instead of asking whether late sleepers face greater health risks, Zhou wanted to find out which types are more vulnerable – and why. He and his co-authors found that among self-described night owls and early birds, there were a total of five subtypes, each associated with a specific pattern of behavior and health.

Among the night owls were:

• Those who did outperform the other groups on cognitive tests, but had more problems with emotional regulation. They often show impulsive behavior or addictions such as smoking, drinking and other substance abuse.
• Those who did not showed improved cognitive abilities and got less physical activity due to their schedules. They also had higher cardiovascular risk and levels of depression.
• Energetic people who loved to work and socialize outdoors. This group was predominantly male and drank more alcohol. They also showed higher testosterone levels on average.

Then, among the early birds were:

• Those with stable lifestyles, low risk-taking behavior, and those who rarely smoked or drank alcohol and enjoyed club activities. They had the fewest health problems overall.
• Whose schedule was more closely linked to depression. This group tended to show more typical female hormone patterns, such as low testosterone.

Although the study did not determine which group was most vulnerable, Zhou suggested that people who wake up at night should get more physical activity and find healthy ways to manage anxiety rather than trying to change sleep schedules. For the high-performance group, he said they should follow their natural rhythms to manage impulsivity and substance use.

In contrast, early risers facing problems may benefit from increased social support.

Scientists suspect that these different chronologies evolved so that groups of early human ancestors could extend their sleep time throughout the night in order to remain alert. night time threats Like hunters.

looking deeper into the study

The study asked people to self-identify their chronotype with a questionnaire, which University of Ottawa professor Rebecca Robillard noted as a drawback.

“Actually the chronologies were determined based on a fairly simple question,” said Robillard, who was not involved in the study.

He said the findings would be stronger with multiple biological measures, such as hormonal or temperature changes, which he believes researchers will do soon.

Still, Dr. Michael Mak of the Center for Addiction and Mental Health in Toronto said one strength of the study was that the investigators validated the findings against another database of young people in the U.S., increasing the scientists’ confidence in their findings and conclusions.

“You’re looking at large, widespread strokes in thousands of people,” said Mak, who was not involved in the study. “Individual differences are probably very large.”

Even if you don’t know your exact chronotype, there’s a handy hack, said Jessica Chalekas, an expert in the socio-cultural anthropology of sleep at Brunel University in London, England, who was independent from the study.

“Take a week or so to really check in with yourself and notice your own patterns,” Chaleckas said. “When do I feel I am doing my best work?”

what to take

What might all this mean for understanding chronology? Robillard described the study as influential in constraining the relationship between chronotype and brain patterns.

As director of the Clinical Sleep Research Unit, Robillard suggested that people adapt their daily schedules to facilitate “their chronotype being able to thrive in their daily routine”.

For those who wake up later, light exposure may be included to push the internal rhythm to a slightly earlier stage.

“The sun is a really strong ally here,” she said. That’s why she recommends taking your morning coffee break outside, even if it’s relatively cloudy.

As much of Canada approaches the spring clock change, Robillard said late risers are more affected by the time change. This is one of the reasons advocate the end of daylight Saving Time.

Recent models suggest that the consistency of one’s sleep schedule also matters, he said. That means yo-yoing between waking up early during the week and sleeping in on the weekend isn’t ideal, because it sends conflicting signals to the body’s internal clock, which struggles to keep track, she said.

Of course, there are limits to trying to change someone’s chronotype, said sleep medicine expert Mak.

“The changes will not be permanent and they probably will not reduce the health risks,” he said.

Night owls ‘not lazy’

In the world of sleep medicine, there has been a lot of research on managing body clock rhythms, said Dr. Maha Alattar, associate professor of neurology and sleep expert at Virginia Commonwealth University. She counters societal misconceptions about people with late-stage chronotype.

“One of the things I do with a lot of those patients, when I find out what they have, is to reassure them that you’re not lazy,” Alattar said.

“You just have this circadian rhythm that’s not in sync with the world schedule. And there’s nothing wrong with you, but it’s your responsibility to make sure you have good habits in the evening and morning.”

Alattar also explained how chronotypes can become dysfunctional in nursing homes or in individuals suffering from dementia. The brain cells that generate the body’s clocks or ability to create circadian rhythms no longer respond to stimulation from the sun.

At the end of the day, we all need to relax. Respect your biology for sleep and wakefulness, Alattar said.

“A good night’s sleep is an investment in your health.”