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Melatonin
Actions/Claims:
Many claims have been made for this hormone, including that it combats jet lag and insomnia, prevents Alzheimer's disease, acts as an antioxidant, boosts the immune system, reduces the risk of cancer and heart disease and slows the aging process.
Research Results:
Our bodies produce melatonin, a hormone. We produce more melatonin at night than during the day. Young adults typically produce .005 mg - .025 mg per day. The body's production of melatonin declines with age. A 70 or 80-year old may have the hormone in amounts so small that it's hard to detect.
- Sleep studies — Due to the increased problems with sleep and the changes in melatonin levels with age, studies have been completed to look at the effect of supplemental melatonin on inducing sleep. Improvement of sleep quality in elderly people and insomniacs has been observed, as has improved sleep and increased alertness during working hours in shift workers. Not all studies have been well-controlled. In some studies, melatonin either had no effect or actually disturbed sleep. Some researchers theorize that positive results only occur if the individual is lacking enough melatonin, although this is not yet proven.
- Jet Lag Studies — Preliminary studies on jet lag showed that subjects taking melatonin had less feelings of jet lag than those who did not take it.
- Cancer Studies — Studies using melatonin in individuals with cancer continue to be in the early stages.
Cautions:
Although some work on melatonin has been positive, there are concerns about recommending its use. Melatonin is a potent hormone. One concern is that high doses, while causing no immediate harm, could have unknown long-term effects. Side effects reported include nightmares, headaches, grogginess, and low sex drive. There are some studies that suggest melatonin may deepen depression in those who have it or induce it in those who are susceptible to it. Melatonin's interactions with other drugs are unknown. Product purity is also a concern.
People who should not take melatonin:
Doses greater than 10 mg may prevent ovulation in some women, so if you are trying to conceive, pass on the melatonin. Pregnant or nursing women should avoid it. Melatonin has not been tested in pregnant women, and small amounts are transmitted through breast milk. People with severe allergies or with autoimmune diseases should also steer clear of the hormone. Melatonin stimulates the immune system and could exaggerate an allergic or autoimmune response. People with immune-system cancers such as lymphoma and leukemia should avoid melatonin because it may further stimulate the immune cells. Most children have naturally high levels of melatonin, and the effects of supplemental melatonin in children are unknown. Due to the discovery that the retina of the eye secretes melatonin, scientists are concerned about the long-term effects of supplemental melatonin on the eye.
Preserving Your Melatonin:
Because of the unknowns about taking melatonin in pill form, you may opt to preserve the natural amount that you have. You can do this by increasing exposure to light in the daytime, minimizing light exposure at night, particularly in the hour or two before bedtime. You can also try a bedtime snack of foods high in melatonin. No study has tested if eating foods that contain melatonin improves sleep; however, the foods are healthful! Melatonin-containing foods include: oats, sweet corn, rice, ginger, barley, cabbage, carrot, apple, pineapple, onion, tomato, cucumber, kiwi fruit, strawberries, and asparagus.