Night owls may have a higher risk of developing breast cancer than morning people

A new study has found that being a night owl or morning lark can have significant impacts on our health.

By Anya Truong-George
Being an early bird may have unexpected benefits according to new research which studied the link between people's sleep patterns and their risk of developing breast cancer, finding those who function better in the morning are likely to be at less of a risk of developing the cancer.
The new study, published in the BMJ, looked at the sleep patterns of more than 409,000 women, from their sleep traits which included sleep duration, insomnia symptoms and self-reported preference between mornings or evenings (their chronotype) along with their breast cancer status of the period of nine years.
Then, using a technique called Mendelian randomisation, the researched analysed the genetic variants associated with those three particular sleep traits.
Their research showed that women who reported a morning preference were at a slightly lower risk of developing breast cancer, one less out of 100 than women who reported an evening preference.
New research has found people who have a preference for the evening have a slightly higher risk of being diagnosed with breast cancer. (Image: Getty)
On average one in seven women will develop breast cancer at some stage of their lives, with certain lifestyle factors potentially heightening your risk, and now this new study has shown that whether you're a morning person or not could be one of them, however the authors are quick to stress that this difference in risk is likely to be smaller than other known risk factors for breast cancer such as alcohol intake and BMI.
This isn't the first study that's linked higher risk of health issues to night owls, for instance a study in 2018 found night owls were more at risk of developing diabetes and 10 per cent more likely to die prematurely when compared to individuals who identified as morning people.

What makes a morning person vs a night person?

Being a morning person or night person comes down to your circadian rhythms or 'body clocks', which is what tells our body when it needs to do things like eat, drink and sleep.
However, not everyone's circadian rhythms are the same – some people, 'morning larks' feel their most refreshed in the morning, but will feel sleepy by 9pm, while others 'night owls' may feel most active in the evenings and have difficulty waking up in the morning.
The authors of a 2017 study featured in the journal of Chronobiology International writes: "The degree of morningness or eveningness is one of the most important aspects of individual differences in circadian rhythms, a phenotype known as chronotype."
According to a study led by the University of Birmingham earlier this year, night owls – who they identify as having an average bedtime of 2.30am and a wakeup time of 10.15am – also have fundamental differences in their brain function compare to morning larks, which means they could be disadvantaged by the constraints of a typical 9-5 working day.
The study found night owls experience a form of jet lag every day if trying to follow a normal working day meaning they're likely to have shorter attention spans, slower reactions, and less energy than morning people.
Lead author of the study Dr Elise Facer-Childs says the research shows there could be a potential intrinsic neuronal mechanism behind why night owls may face cognitive disadvantages when forced to work in a the 'normal' work hours.
"To manage this, we need to get better at taking an individual's personal body clock into account – particularly in the world of work," she says.
"A typical day might last 9am-5pm, but for a night owl this could result in diminished performance during the morning, lower brain connectivity in regions linked to consciousness and increased daytime sleepiness. If, as a society, we could be more flexible about how we manage time we could go a long way towards maximising productivity and minimising health risks."
According to a study published earlier this year, night owls experience a form of jet lag when they try and fit into the 'normal' working day schedule. (Image: Getty)

Can you turn into a morning person?

While research hasn't yet indicated whether you can completely change your chronotype, there could be ways to improve some of those feelings of jet lag.
In a follow up study published in the journal Sleep Medicine earlier this month, Dr Facer-Childs and researchers wanted to find out whether routine adjustments might help night owls and found that with a few adjustments to their routine, volunteers demonstrated improvements in cognitive performance and increased reaction time in the morning.
They also reported reaching their 'peak' performance capability in the afternoons, rather than in the evenings as they had before being part of the study.
The four changes the volunteers were asked to make over a three week period included:
  • Waking up 2-3 hours earlier than they usually world and trying to get maximum exposure to outdoor light in the morning
  • Going to bed 2-3 hours earlier than they usually would and minimising exposure to light sources in the evening, before bed
  • Keeping to the same wakeup times and betimes every day, including at weekends
  • Eating breakfast first thing after waking up, lunch at a consistent time each day, and dinner no later than 7pm.
There's still a lot of research to be done around the area and debate about whether workplaces should become more flexible to work around these hours.
In the meantime though, if you feel like you fall into the category of a night owl, try making a few adjustments to your daily schedule. If you find it difficult to sleep earlier, you're likely to soon discover that waking up earlier is likely to make you sleepier earlier too, plus as the studies have suggested, your body will thank you for it!