You’ve just flown
into Boston from London, and you’re staying with friends. It’s time
for happy hour and dinner. They’re talkative and lively, ready to
party. But you, you’re a basket case. You haven’t slept much in the
last 24 hours, nor eaten on a familiar schedule, and your body
thinks it’s past midnight.
Hours later, they
finally let you go to bed. You’re exhausted, but you can’t sleep
well. When you finally arise the next morning, things are not much
better. It’s possible you may feel anxiety, have some bowel disorder
and be dehydrated, as well as have a headache and be irritable.
coordination problems, dizziness and even some memory loss are
possible symptoms of your condition. In some cases, there may be
heartbeat irregularities, as well.
If you are
otherwise healthy, then it’s most likely that you’re suffering from
desynchronosis or, more commonly, jet lag. The severity of these
symptoms vary from person to person, but are inevitably at least
Jet lag means that
you’ve traveled very fast, jet speed, from east to west, or vice
versa, and crossed at least one time zone. One or two time zones is
not usually very noticeable, but three or more usually has
disturbing effects. Some feel that traveling west to east is more
difficult than east to west.
traveling north to south or south to north at the same speed for the
same distance does not incur jet lag. And traveling by bus or train
is so slow that jet lag is seldom a problem.
What has happened
is that your normal daily rhythms are out of sync, and your inner
body clock has become disoriented. It’s not sure whether you should
be awake or asleep or eating and, if so, what meal. And why is the
sun up at this hour?
Jet lag is a
temporary condition that goes away at different speeds for different
people, but a common guideline is that it takes about a day for each
time zone you cross. So you can imagine the constant psychological
and emotional upheaval there must be for people who regularly travel
cross country for a couple of days at a time.
In addition to
rapid travel across time zones, a condition similar to jet lag is
sometimes experienced by those who work a swing shift schedule: 9
a.m. to 5 p.m. some days, 4 p.m. to midnight on others, for example.
There are also some sleep disorders that can produce effects like
this clock, and where?
Your body actually
has several different rhythms, cycles that may occur daily, weekly,
monthly and more. The one that is most disrupted by jet-speed,
east-west travel across time zones is the one that happens
approximately daily, circadian.
A small part of
your brain called the hypothalamus has several essential functions,
including producing the hormones that control different cells and
organs. Its primary function is keeping your body in balance, to
which end it regulates temperature, thirst, hunger, sleep, mood, sex
drive, breathing, blood pressure and more.
Your body clock
resides in a small V-shaped cluster of cells in the hypothalamus.
It’s like a brain pacemaker that regulates your circadian rhythm of
sleeping and waking. It’s like an hour hand on your watch
coordinating not only the timing of wakefulness and arousal, but
also the stages of sleep.
it get off-schedule?
Your clock is
largely selfregulating, but it relies on external cues to keep it
consistent with a 24-hour schedule. Technically, these cues are
called “zeitgebers,” which is German for “time givers.”
influential zeitgeber is the light that strikes your eyes, even with
people who are blind. As the daylight changes slowly with the
seasons, your clock unconsciously resets itself to accommodate to
the changing light pattern. However, if the change in the zeitgebers
is too fast, your clock can’t adjust itself to keep up, and you wind
up with jet lag.
Time, although an
imaginary concept created by us humans, has an effect on your body
clock. As you read your watch, for example, or keep to work, train
and other schedules, you are demanding that your body be aware of
the timing for different tasks and social events. This awareness
puts a cognitive pressure on your body clock to stay on schedule. So
when the dinner hour at your travel destination differs
significantly from your accustomed schedule, then your clock
naturally gets confused about what you want to do.
In addition, in
that small nucleus of your brain where your body clock resides,
there are receptors for a hormone called melatonin. Melatonin is
produced in a regular daily rhythm by a gland deep in your brain and
between the two halves of it; this is the pineal gland. Research has
shown that the melatonin level climbs after dark and ebbs after
dawn. It causes drowsiness for some people, and its light-sensitive
nature helps regulate your circadian cycle of sleep and wakefulness.
In some sense, it is the lackadaisical regulation of this and other
hormones that results in the jet lag experience.
What to do
about jet lag
You can do a lot
to minimize the effects of jet lag.
First, stay fit.
This means getting daily exercise and plenty of rest, as well as
eating a balanced diet.
Next, drink plenty
of water during your trip. Avoid alcohol and caffeine, which may
make the jet lag symptoms worse.
Move around on the
airplane. At least once an hour, get up and walk the aisle.
If you are not on
a tight schedule, consider breaking up your long trip into shorter
segments. Of course, this may be a bit difficult if you’re flying
across the Atlantic or Pacific oceans.
If you’re staying
for several days at your destination, immediately change your
schedule to the local one. You can also start changing your schedule
over a period of days before you leave on your trip. For myself, if
I’m staying for just a day or so in California, for example, I find
it better to try to stay as close as possible to my eastern time
For some people,
using over-the-counter melatonin has a beneficial effect. Do this
only after consultation with your doctor, as melatonin can have side
effects like daytime sleepiness, headaches and dizziness. It can
also interact negatively with other medications you may be taking,
including blood thinners and birth control pills.