Posted at 23:27h
Melatonin is a natural hormone released in the human brain by the pineal gland. It can also be ingested as a supplement or with certain foods.
The levels of melatonin in the body vary throughout the day, and higher levels of melatonin are associated with the onset of sleep. Human sleep is regulated in part by exposure to light which stimulates signals sent from the eye's retina to the brain. This area of the brain is responsible for maintaining sleep cycle by controlling functions of the body involved in feeling awake or sleepy.
One of these functions is to delay the release of melatonin upon exposure to light early in the day. Then when darkness arrives melatonin is actively secreted throughout the night.
Rather than functioning as a typical "sleeping pill", more evidence supports the ability of melatonin supplementation to help reset the body's internal clock. That means improved sleep when using melatonin for jet lag or shift work. On a weekly basis, supplementation may be beneficial for resetting your bedtime earlier on Sunday night after staying up late Friday and Saturday nights.
Melatonin also functions as an antioxidant protecting cells in the body. As oxygen is metabolized, reactive oxygen species are produced which have harmful effects on cells. Antioxidants such as melatonin remove these intermediates and inhibit some of the harmful reactions. Given these effects, antioxidant supplementation has been under investigation for it's role in preventing diseases such as cancer, coronary heart disease, and cognitive decline. Not all data has shown clear benefits, but certain subgroups of participants showed promising results.
If you are considering taking over the counter melatonin pills, keep in mind that higher doses are not necessarily better. In fact, some studies suggest decreased benefits at higher doses, and effective doses in the range of 0.3 - 1.0 mg. Pills sold at stores like CVS can be 3 or 5 mg in strength. Save your money and go with the smaller dose, or even split pills....