Many of us look forward to the fall version of daylight savings time, when we get to crank back our clocks and watches and savor an extra 60-minute block of sleep. But you may be surprised to learn that your body has a time-monitoring mechanism of its own, and that lost hour of daylight in the evening can throw off your body’s biological rhythms, which can have some pretty widespread effects on your health. The same thing occurs after you fly across three or more time zones: you lose or gain hours of daylight, causing possible fatigue, sluggishness, dizziness, irritability and mood swings upon reaching your destination. This phenomenon is commonly known as jet lag. Let’s explore what happens to your body when you lose or gain an hour or more of daylight, and how a hormone you naturally produce can fight this disorder.
What causes jet lag? Your body possesses a kind of “master clock,” centered in a part of your brain called the hypothalamus. This biological clock controls your circadian rhythms, or daily activity cycles that are based on 24-hour rhythms within your body. When light hits certain receptors located in your retina (a part of your eye), those receptors send a signal to the master clock in your brain. Changes in your environment, such as light and darkness, affect your master clock and disrupt your circadian rhythms. Even an extra hour or more (or less) of daylight can interrupt your normal circadian rhythms, which in turn can affect your sleep patterns and mood. Flying through time zones extends or shortens the amount of daylight you experience within a 24 hour period, which causes interruptions in your circadian rhythms, resulting in the condition known as jet lag.
How melatonin fights jet lag: After your retina perceives daylight, your master clock triggers a gland in your brain called the pineal gland to stop production of the hormone: melatonin. Melatonin levels increase when your retina photoreceptors experience darkness (at nightfall), which promotes a feeling of drowsiness and helps you sleep. Therefore, an extra two or three hours of daylight, as can be experienced on a long-distance flight, can result in less melatonin production and thus lead to restlessness, insomnia and mood swings. Fortunately, taking a melatonin supplement can help you readjust your circadian rhythms and resume your normal sleeping cycle.
Suggested dosage of melatonin to fight jet lag: Studies indicate that taking .5 to 5 mg (milligrams) of melatonin after reaching your final destination, and one hour before bedtime, may effectively treat the symptoms of jet lag. You may be sensitive to melatonin supplements, so consider taking the lowest dose (.5 mg) the first time you try this supplement to ensure you will not suffer any ill effects.
Jet lag can be an unpleasant side effect of a long flight. Fortunately, you can fight this condition naturally with melatonin, and help get your master clock, sleep cycle and circadian rhythms all back on track and running like clockwork again.
- http://www.nigms.nih.gov/Education/Factsheet_CircadianRhythms.htm Circadian rhythms
- http://www.studyabroad.illinois.edu/userfiles/pages/jetlag.aspx Jet Lag
- http://umm.edu/health/medical/altmed/supplement/melatonin (melatonin information, dosage)
- http://www.vanderbilt.edu/AnS/psychology/health_psychology/melatonin.htm (melatonin information)
Originally posted 2013-11-06 09:50:54.