Melatonin (N-acetyl-5-methoxytryptamine) was isolated in a laboratory as early as 1958. The hormone is produced from the amino acid tryptophane and secreted by the epiphysis, a gland the size of a pea also known as the pineal gland. It is a kind of sister organ to the hypophysis and is placed in the middle of the brain, which is a primitive area which deals with the self-regulating parts of the body, emotional behaviour, and sexuality. People previously believed that this gland was rudimentary, i.e. a leftover from an early stage of development, where the gland functioned as a light-sensitive receptor.
Today we are aware that the pineal gland is a part of the hormone- and nervous systems. Our own production of melatonin peaks at the age of six and declines steeply in puberty - the pineal gland calcifies with age and the melatonin production correspondingly decreases. The gland receives nerve impulses from light which reaches the retina. When light is received by the retina, particularly during daytime or in summer, the production of melatonin is decreased.
The body's internal clock has its own rhythm, which is longer than 24 hours. Normally, it varies between 24.5 and 25 hours. The light received by the retina every day adjusts the inner clock and protects our daily rhythm from being disturbed.
When darkness falls, the pineal gland will start producing melatonin and within a few hours, the production reaches its maximum. Certain things can disturb this course; if you have consumed alcohol, for example, your body's production of melatonin will be inhibited, and if you turn the light on during the night, e.g. for going to the loo, the production of melatonin will stop immediately and it will only slowly be resumed.
Melatonin and cancer
The nocturnal production of melatonin is important for the prevention of cancer. For this reason our well-being depends on our sleeping in darkness all night through so that we reap the maximum benefit of the cancer preventing- and antioxidant effects of melatonin.
A large Danish population survey has shown that women increase their risk of cancer after as little as 6 months working night time hours. After 6 years of such work the risk is increased 70%. Further research indicates that female flight personnel - particularly those with sleeping problems - run the double risk of contracting breast cancer.
Women need the production of melatonin that occurs mainly at night because the hormone inhibits the production of oestrogen which is necessary for the survival of some tumours.
When taking a melatonin supplement, it corresponds to telling the body's internal clock that there is 1/2 - 1 hour to midnight. Therefore, supplements should be taken before bedtime and preferably 1/2 - 1 hour before midnight. People with night jobs should also take their melatonin supplement before midnight at the normal bedtime.
Melatonin is used for jet lag and sleeping problems - e.g. in connection with shift work. Furthermore, the daily rhythm of blind people has successfully been normalized with a supply of melatonin.
Melatonin is not addicting- even in high doses - and there are at present no reports on side effects of melatonin.
Pregnant women and persons under the age of 40 should not take melatonin supplements. Additionally, one should not take more than 5 mg. a day.
General recommendations of melatonin supplements are:
From 40 years: 0,5 - 1 mg. before bedtime
From 45 years: 1 - 2 mg. before bedtime
From 55 years: 2 - 2,5 mg. before bedtime
From 65 years: 2,5 - 3,5 mg. before bedtime
From 75 years: 3,5 - 5 mg. before bedtime
Some countries are very restrictive when it comes to melatonin. In these cases, it could be a good idea to eat foods containing tryptophan or take supplementary tryptophan because it is a precursor to melatonin.
