By Andrea DeBrish
Do you stay up late at night? Do you sleep in on the
weekends? You might be suffering from what is referred to as social jetlag.
A persons sleep pattern, the time they naturally want to
fall asleep and wake up, is their chronotype. This is regulated by a person’s
circadian rhythms. That is the 24 hour pattern a person’s bodily functions
follow based off of the daily rotation of the earth. This circadian biological
clock is controlled by part of the brain called the Suprachiasmatic Nucleus
(SCN). The SCN is located in the part of the brain known as the hypothalamus
and is largely stimulated by signals of light and dark. Light signals the SCN
for the release of hormones including cortisol and raising of the body
temperature. Light also suppresses levels of melatonin which is a hormone
involved in falling and staying asleep.
The two general chronotypes are the early chronotype and
late chronotype referring to the relative natural time at which they would like
to wake up in the morning. The late chronotype is more common in the population
but in many industrialized societies, there is an early social schedule where work
and school days typically start at 8am. People with the late chronograph, often
referred to as owls, cannot fall asleep early enough get ample sleep before
rising in the morning to make it to work on time. They can then accrue a sleep
debt of lost hours. To make up for this debt, they will often sleep in late on
the weekends, trying to reduce their fatigue. This creates the jetlag effect
where on the weekend they have effectively gone west a couple of time zones and
then come back for the work week.
Social jetlag can
especially be a problem for teenagers who naturally experience a sleep phase
delay. This means they often have trouble getting to sleep before 11pm and then
the social clock requires them to be up and ready for school at 8am. This does
not leave enough time for them to get the sleep they need.
There are other problems and behaviors which can be
associated with social jetlag aside from tiredness. It has been shown to
correlate with caffeine and alcohol consumption in addition to tobacco use.
This can be especially problematic when there is such an increased chance for
social jetlag among teenagers. Late chronotypes have also shown less general feelings
of well being and increased psychological disturbance which can also be especially
problematic among teenagers.
Another study done showed a relationship between obesity and
social jetlag. Not getting enough sleep increased a person’s probability of
being obese. Both sleep timing and duration related to metabolism.
It has long been known that sleep is important for a well
functioning, healthy human. It is now becoming more apparent though how our
artificial system of time can have negative effects on healthy sleep patterns. By
having designated work and school hours starting at 8 am people are being
forced to work against their natural sleep patterns to their own detriment.
There may be a movement in the future for companies to be
more flexible with scheduling to allow people to work within their own
circadian rhythms. This could perhaps even lead to greater productivity of
their employees if they aren’t completely exhausted all the time. It would also
be good for schools to recognize the sleep phase delay in teenagers and adjust
their times accordingly as well. It would also help to remove the system of
daylight savings time which effectively messes up everyone’s internal clocks
twice a year.
Until the social clocks can get changed, there are some
things a person can do to help ease their own social jetlag. One is exposure to
bright light right upon waking up. This light signals the SCN which sends other
signals out to express all the right hormones to wake up. This is using the
cues we get from nature to our advantage. Another step to help is to turn lights down
before bed and avoid work or any other mentally taxing activity which could
keep you from falling asleep. It’s also important to try to keep the same
schedule for everyday so your body can attempt to reset its internal clock.
References:
“Information
about Sleep.” Teachers Guide. National Institute of Health. Web. 08 Feb. 2013.
<http://science.education.nih.gov/supplements/nih3/sleep/guide/info-sleep.htm>.
Roenneberg, T., K.V. Allebrandt, M. Merrow, and C. Vetter.
2012. Social Jetlag and Obesity. Current Bioloogy 22:939-943.
"Sleep Drive
and Your Body Clock." National Sleep Foundation. 2011. Web. 08
Feb. 2013.
<http://www.sleepfoundation.org/article/sleep-topics/sleep-drive-and-your-body-clock>.
Wittmann, M., J. Dinich, M, Merrow, and T. Roenneberg. 2006.
Social Jetlag: Misalignment of Biological and Social Time. Chronobiology
International 23(1&2):497-509
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