Where it comes from: Melatonin is the major hormone naturally produced by the pineal gland, located in the brain. The body has an internal clock that controls the natural cycle of sleeping and waking hours—it also controls how much melatonin your body makes. Normally, melatonin levels rise in the mid to late evening, remain high for most of the night, and then drop in the early morning hours. Light also affects how much melatonin your body produces.
A minimal amount of melatonin is found in foods such as rice, barley, sweet corn and oats. Melatonin is also sold as capsules and tablets.
What it’ll do for you: Melatonin helps the brain determine day and night to regulate sleep cycles and circadian rhythm. It’s believed that melatonin supplements can reduce jet lag, regulate sleep-awake cycles, stop or slow the spread of cancer, prevent and treat migraines and enhance sex drives. Here, a look at the two types of people who could benefit the most from melatonin supplements:
- Night-shift workers
Due to melatonin’s impact on the sleep-awake cycle, it’s often used among night-shift workers. In one study, researchers at Rush University Medical Center in Chicago gave night-shift workers 3 milligrams every day before bed and found that they slept 73 percent more soundly than those taking a placebo—despite going to bed at daybreak.
- The jet lagged
When air travelers cross several time zones, their body’s internal rhythms are often thrown out of step with the day-night cycle at the destination. Melatonin supplements are often suggested to help travelers re-align their sleeping habits. In 2002, British researchers examined 10 previous trials and found that melatonin, when taken close to the target bedtime at the destination, decreased jet lag from flights crossing five or more time zones. The timing of the melatonin dose is important: if it is taken at the wrong time (too early in the day), it is likely to cause sleepiness and delay adaptation to local time.
Suggested intake: While small amounts of melatonin are in certain foods, it’s difficult to quantify how much melatonin-containing foods would have to be consumed to affect mood and sleep.
Supplement manufacturers recommend dosages from 3 to 5 milligrams. Doses above 5 milligrams appear to be no more effective. “There is concern about the safety, purity and potency of melatonin sold in health food stores and pharmacies,” Greaves points out. Check with your doctor before starting any supplement, especially if you are taking other medications.
Associated risks/scrutiny: “There have been no harmful effects reported from short-term use, however long-term effects and safety have not been studied,” says Greaves. There are a few minor side effects associated with short-term use of melatonin but they will subside when you stop taking the supplement. Side effects include sleepiness, changes in blood vessels that may affect blood flow, lower body temperature, stomach problems, headaches, morning grogginess and vivid dreams.
Morning use of melatonin may affect alertness and reflexes. Do not take if using other sleep aids. Avoid melatonin from animal pineal gland due to potential contamination from toxins.
by Lisa Freedman