In 10 seconds? Research suggests that “social jet lag” increases the chance of heart disease, can lead to obesity but also increases the risk of depression. Luckily, a consistent sleep pattern and revised meal times can be good counter-measures.
What is social jet lag as opposed to jet lag? With jetlag, you have trouble going to sleep at the right time when you find yourself in a new time zone. Social jetlag can be more chronic – it occurs when we sleep less on workdays and get up much later on our days off. It affects a lot of us, particularly shift workers and teenagers – the latter can even suffer from it when daylight saving time gets adjusted, just by 1 hour.
Do you mean even healthy youngsters? Yes. A study of teens in Northern Russia between 2011 and 2014 — a period when their time zone was shifted forward by an hour by law — showed that they experienced significant misalignment between their social and body clocks, affecting their sleep, mood, and behavior. A Swedish study of over 1500 students reported that 53.9% of them suffered from social jetlag and that screen time and texting were significantly associated with the condition. Meanwhile, a US paper suggested that 9 out of 10 Americans used some sort of device before sleep and this caused sleep problems.
OK, but why is it a problem if I sleep it off during the weekend? Well, if you do this regularly, you'll get similar effects to performance-degrading jetlag, like feeling sluggish and being much less efficient. Again, what you are doing is keeping your circadian (body) and social clocks misaligned. While our internal clocks set times for when we get sleepy and get hungry, our lifestyles can dictate that we disregard the signs and follow our ‘social’ clock. But this out-of-sync circadian clock can increase the risk of obesity, heart disease, and diabetes.
I heard about that, but depression as well? Yes. A Japanese study involving 1400 non-shift workers found that that the risk of depressive symptoms approximately doubled if the worker developed a 1 to 2 hours social jetlag. A more recent UK study involving 85,000 people also reported a higher occurrence of depression and anxiety among the ‘socially jetlagged’.
But I’m a night owl, I like to stay up… Indeed, different people have different natural internal schedules, or chronotypes. This tells us when we need to go to bed. Sleep experts claim that finding which chronotype you are and then working with it will help you sleep and perform better. In other words, if due to work your sleeping times don’t match your chronotype then you will feel social jetlag. But the authors of the above UK study also noted that early risers reported fewer depressive symptoms.
What if being a night owl is genetic? Good guess. Your chronotype is determined by your PER3 gene. If you have a long PER3 gene, you are an early riser and need 7 hours of sleep a day. A shorter PER3 gene means you are a late riser and can get by with less sleep. Researchers have identified another gene, CRY1, more active in individuals who take it to the extreme and stay up until the early hours and then get up late.
What can I do, re-align my body clock? Emerging research suggests that delaying meal times to match later bedtimes could mitigate the effects of sleeping late. And for those who get less shut-eye overall during the week, the advice is to stick to a regular sleep schedule, which sadly means no lie-ins on the weekend. On the other hand, scientists have also tested if ‘night owls’ could bring forward their sleep times. Participants in a small randomized trial were asked to shift their sleep-wake patterns by 2-3 hours forward over six weeks and create new routines. The researchers have found that those who managed to follow the prescribed regimen, indeed managed to shift their body clocks forward and reported fewer depressive symptoms. This was a small trial so other studies need to back it up but there is a growing body of evidence that tackling social jetlag can benefit not just our physical but mental well-being too.
How did the night owls turn into early larks?
The participants of the trial were asked to change their sleeping patterns for six weeks – a period needed to form new habits.
Not only do they have to try to go to bed and get up 2-3 hours earlier than they were used to, but they were also told to catch some sunlight in the mornings.
The regimen included exercising in the mornings rather than later.
And, mealtimes had to be kept regular with an early breakfast and dinner before 7 pm.
Karolina distilled 15 research papers saving you 52.5 hours with an evidence score of 3.9 out of 5