Dr Leigh Martens

Being a 'night owl' could kill you, study finds

By Honor Whiteman

I wake up at 5.15 a.m. each day to get to work on time, so going to bed at a reasonable hour is a must for me. According to new research, it's also beneficial to my health; scientists found that "night owls" have a higher risk of early death.

Researchers find that being a night owl can take its toll on health.

Being a "lark," as morning people are commonly referred to, has its downsides; I love the idea of staying up late to watch movies, or even going to a club until the early hours and stumbling to bed at 6 a.m. Sadly, I'm usually asleep on the couch by 10 p.m.

Reading the results of this latest study, however, has made me realize that being a lark may not be so bad, after all — for my health, at least.

Kristen Knutson, from the Northwestern University Feinberg School of Medicine in Chicago, IL, co-led a study that looked at the effects that being a night owl might have on health and mortality.

Their results are now published in the journal Chronobiology International.

By assessing the bedtime habits of more than 430,000 adults over a period of 6.5 years, Knutson and her team found that night owls are more likely to develop diabetes and neurological and psychological disorders.

And that's not all; the study also found that night owls are 10 percent more likely to die early than morning larks.

So, what are the reasons behind this higher risk of disease and death?

Knutson says that being a night owl could interfere with our biological clock. This is the mechanism that regulates physical, mental, and behavioural processes over an approximate 24-hour period.

Our biological clock mainly responds to light in our environment — light tells our body that it is time to be awake, while darkness tells our body to go to sleep.

But when the clock is shifted out of sync — through exposure to light at a time when we should be sleeping, for example, which is typical of night owls — this can have negative effects on our health.

As Knutson suggests, "It could be psychological stress, eating at the wrong time for their body, not exercising enough, not sleeping enough, being awake at night by yourself, maybe drug or alcohol use. There [is] a whole variety of unhealthy behaviors related to being up late in the dark by yourself."

A 'public health issue that can't be ignored'

Still, it's not all doom and gloom for night owls; Knutson claims that individuals who like to go to bed later and sleep in might benefit from more regular bedtimes, and adopting a more healthful lifestyle could help.

Perhaps unsurprisingly, she notes that making the transition from a night owl to a morning lark could also be beneficial to health.