Hailed by some as a potent anti-aging hormone, melatonin has been credited with almost miraculous effects on a wide variety of ailments, including cancer. It is probably most effective, however, as a natural sleep aid to ease insomnia and overcome jet lag.
What it is?
First identified in 1958 (and available on prescription in Australia and New Zealand), this naturally occurring hormone is manufactured by the pineal gland, a pea-sized organ deep within the brain. All humans and most animals secrete melatonin throughout their lives, with the highest levels occurring during childhood. As we age, however, the production of melatonin declines, leading some researchers to theorise that melatonin supplementation might benefit all older people. Interestingly, natural melatonin levels vary widely: about 1% of the populations have very low levels, and another 1% have levels 500 times above normal. There's no correlation, however, between these amounts and specific health concerns or sleep patterns.
What it does?
One of the main functions of melatonin is to regulate cycles of sleep and wakefulness. It does so by helping to set the brain's internal clock, creating what are known as circadian rhythms – the body's daily biorhythms that govern everything from sleeping and waking times to digestive functions and the release of a variety of hormones linked to reproduction and other body processes. In order to produce melatonin, the body responds to light cues, making more when it's dark outside (production begins each evening around dusk and peaks between 2 a.m. and 4 a.m.) and less during the day. This daily cyclical secretion of melatonin is what tells the body when to sleep and when to wake.
Melatonin may be most effective as a sleep aid. Various studies of young and elderly adults indicate that in some people melatonin shortens the time needed to fall asleep and improves sleep quality by decreasing the number of times they wake during the night. It may be beneficial when chronic pain or stress causes sleep disturbances. Melatonin can also help to restore normal sleep patterns in people who do night-shift work or in those suffering from jet lag as a result of crossing time zones. Moreover, it works without producing the addictive effects of conventional sleep medications.
Many other claims are made for melatonin. Interest in it as an anti-aging formula was sparked by an animal study in which nightly administration of the supplement to elderly mice prolonged their lives by 25%. However, there have been no studies to show that melatonin supplementation delays ageing in humans. Some research suggests that it may boost the immune system. And it may be an even stronger antioxidant than vitamins C or E or beta-carotene, hunting down and destroying the naturally occurring, cell-damaging compounds called free radicals that can lead to heart disease, cataracts and other age-related degenerative changes. More research is needed to determine whether melatonin helps to prevent these and other conditions.
Some studies suggest that, when combined with certain drugs, melatonin may help to destroy malignant cells. Another study conducted in Holland in 1995 found that, when taken in conjunction with birth control pills, melatonin has an oestrogen-countering effect that may offer protection against some forms of breast cancer. In addition, some reports indicate that melatonin may reduce some of the nerve damage associated with both Alzheimer's and Parkinson's diseases. And a 1997 study from Italy revealed that it may also have beneficial effects on the blood vessels and thus play a role in reducing the risk of stroke and heart attack. More research is needed to determine the effectiveness and long-term safety of melatonin for these and other uses.
- Relieves insomnia.
- Promotes restful sleep, even during night-time pain or stress-related sleep disturbances.
- Diminishes the effects and shortens the course of jet lag.
- Adverse drug interactions have been reported in people taking commonly prescribed anti-depressants (including Prozac and MAO inhibitors) or steroid or sedative drugs.
- Reminder: If you have a medical or psychiatric condition, talk to your doctor before taking supplements.
How to take it?
For insomnia: Take 1-3 mg before bedtime.
For jet lag: Take a 3 mg dose on your day of travel, followed by 3 mg before bedtime for the first three or four nights at your final destination.
For shift work: Take a 3 mg dose at your desired bedtime (at 8 a.m., for example) after working a night shift.
Guidelines for use:
To combat insomnia, stick to a precise schedule, taking supplements at the same time every morning. Start with the lowest dose, and increase it as needed.
Possible side effects
No serious risks associated with melatonin use have been reported. In one US study, patients who took very high doses (6000 mg nightly) for one month had no major side effects. But long-term studies of six months or more are lacking.
For most people, melatonin causes drowsiness 30 minutes after taking it. This effect may last for several hours, so you should not drive or handle heavy machinery during this time. Other side effects can include headache, stomach upset, lethargy or disorientation. Some people report that melatonin can cause fuzzy thinking upon waking, or vivid and sometimes unpleasant dreams, and can even make insomnia worse. Others find that the effects wear off quickly with continued use.
- Although readily available in the US, melatonin is classified as a drug in Australia and New Zealand, and is available only on prescription.
- Most melatonin supplements (even those called 'natural') are produced synthetically and are safe to buy. They're identical to natural human melatonin. However, be wary of melatonin products derived from animal glands; they may contain dangerous impurities.
- A US study of 52 airline employees showed melatonin to be a very effective remedy against jet lag, significantly shortening the normal one-week adjustment period. Other studies with more than 400 people determined that the hormone reduces symptoms of jet lag by about 50%, on average, on both eastward and westward flights.
- Preliminary studies at the Oregon Health Sciences University in Portland found that tiny doses of melatonin may be effective for wintertime blues. Depressed patients who received several doses of 0.1 mg of melatonin in the afternoon showed significant mood improvements, compared with those who received no melatonin or a larger single dose in the morning. Scientists speculate that small afternoon doses may mimic the way melatonin is naturally released by the body, but caution against drawing conclusions until further studies are completed.