Family Living Focus: Your Internal Clock Affects Your Health
Gail Gilman, Family Life Consultant, M.Ed., C.F.C.S. and Professor Emeritus, University of Minnesota
Do you live by the clock, checking your watch so you are not late for work,
morning coffee gatherings, church, or appointments? While you struggle to
stay on time for your daily activities, your body has its own internal
clock. This biological clock helps you feel alert at work, hungry at
mealtimes and drowsy at night. When your internal clock is out of whack,
your health can suffer.
Scientists have long known that the human body has daily rhythms, called
circadian rhythms (circadian is Latin for “around a day”). These natural
rhythms are coordinated by a tiny region in your brain. This “master clock”
generally operates on a 24-hour cycle, and it adjusts to several cues in
your surroundings. The most important cue is light and darkness.
During the day, when it is light outside, the brain’s master clock sends out
signals to other brain regions to make hormones that will help keep you
awake, boost your heart rate, and give you energy. In the evening, when
less light enters your eyes, the master clock triggers production of a
hormone called melatonin. Melatonin makes you feel drowsy and helps you
stay asleep.
The brain’s clock affects various body functions, including body
temperature, hormone levels, urine production and blood pressure.
Many processes are patterned around a 24-hour cycle: sleeping, eating,
waking, drinking and even health-related events. For instance, heart
attacks are more likely to occur early in the morning, when the level of a
hormone called cortisol starts its daily rise. Time of day has also been
shown to influence the effectiveness and side-effects of certain drugs.
When you fight against your circadian clock and your activities take you out
of sync with day and night, your health may suffer. The schedules of shift
workers who must be on the job after the sun goes down are at odds with
their biological clocks. These people often find themselves sleepy at work.
They may also have trouble falling or staying asleep during daylight hours
after work. Studies show that shift workers have increased risk for heart
disease, digestive disturbances, cancer, and other health problems.
Another less severe disruption of the circadian clock is jet lag. It’s
caused by traveling across time zones. Jet lag is usually more severe for
eastbound travelers because their days are shortened, and the brain has more
trouble adjusting to a shorter day than a longer one. Some studies suggest
that taking melatonin pills just before bedtime may help jet-lagged
travelers adjust to new time zones. But the scientific evidence for using
melatonin to treat sleep disorders is still unclear.
Researchers continue to explore exactly what makes our biological clocks
tick. The answers they find may eventually lead to new treatments for sleep
disorders, jet lag and other health problems.
Keep Your Inner Clock on Track
* Stick to a regular sleeping schedule.
* Avoid caffeine late in the day, and do not drink alcohol to help you
sleep.
* Get rid of light and sound distractions in your bedroom.
* Do not exercise within 2 hours of bedtime. It may delay the release
of melatonin.
Be sure to watch for more Family Living Focus information from Gail Gilman,
Family Life Consultant, M.Ed., C.F.C.S. and Professor Emeritus – University
of Minnesota in next week’s paper.
