Melatonin is a hormone produced in the pineal gland, a small gland in the brain that helps regulate sleep and wake cycles. The synthesis and release of Melatonin are stimulated by darkness and suppressed by light, suggesting the involvement of Melatonin in circadian rhythm and regulation of diverse body functions. Small amounts of Melatonin are found in foods such as meats, grains, fruits, and vegetables. It is also available as a dietary supplement, though it has no known nutritional value. Natural Melatonin levels decline gradually with age. Some older adults produce very small amounts of Melatonin or none at all. Supplemental Melatonin may have a hypnotic action. It may also have antioxidant activity. It possesses antioxidant and anti-apoptotic activity. Synthetic Melatonin supplements have been used for a variety of medical conditions, most notably for disorders related to sleep. Preliminary evidence suggests that it may also help strengthen the immune system.
Many researchers also believe that Melatonin levels are related to the aging process. For example, young children have the highest levels of nighttime Melatonin. Researchers believe these levels diminish as we age. In fact, the decline in Melatonin may explain why many older adults have disrupted sleep patterns and tend to go to bed and wake up earlier than when they were younger. Although results are still controversial, studies suggest that Melatonin supplements help induce sleep in people with disrupted circadian rhythms (such as those suffering from jet lag or poor vision or those who work the night shift) and those with low melatonin levels (such as some elderly and individuals with schizophrenia). Research suggests that Melatonin may be modestly effective for treating certain types of insomnia. It has been shown to stimulate cells called osteoblasts that promote bone growth. Since Melatonin levels may be lower in some older individuals such as postmenopausal women, current studies are investigating whether decreased Melatonin levels contribute to the development of osteoporosis, and whether treatment with melatonin can help prevent this condition. Melatonin supplements may benefit menopausal women by promoting and sustaining sleep. Peri- or postmenopausal women who use Melatonin supplements to regulate sleep patterns should do so only for a short period of time since long term effects are not known. Melatonin is also being studied for the treatment of sleep problems in blind people. People who are blind with no perception of light, can have sleep problems such as sleeping during the day and being awake at night.
References:
University of Maryland Medica Center. http://www.umm.edu/altmed/articles/melatonin-000315.htm
Medline Plus. http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-melatonin.html
WebMd. http://www.webmd.com/sleep-disorders/tc/Melatonin-Overview
