The pea-sized pineal gland, located deep in the brain, has only been studied in recent years. However, it has long been revered in Eastern traditions as the mystical "third eye" and, in a way, it is. The pineal gland is sensitive to light and has pigment cells like those in our eyes. It responds to light coming in through the eyes and uses those light signals, or lack of them, to regulate our circadian rhythms. Commonly called our body clock, this is what lets us know when to sleep and when to wake.
The pineal gland produces melatonin, the hormone that controls these body rhythms, but it encompasses much more than the daily sleep/wake cycle. It also regulates the release of hormones that control body temperature, hunger, energy, and even mood, because these fluctuate on a 24-hour cycle as well. Due to its unique effects on other hormones, melatonin, in a sense, orchestrates the very dance of life, the growth phases in childhood, the onset of puberty, and even the systemic decline that we call ageing.
All of these processes are ultimately controlled by the waxing and waning levels of melatonin. On a daily basis, the levels of this hormone vary significantly. Melatonin is secreted primarily during the dark nighttime hours, as we sleep.
If you have problems getting to sleep, take melatonin an hour or two before going to bed. If your sleep problems involve waking up in the middle of the night, take it just before going to bed. The dose you take will depend on your age.
Other conditions related to circadian rhythm respond well to melatonin. It has only been during the past few decades that this phenomenon has surfaced, and it can really take a toll on your body. Muddled thinking, crankiness, fatigue, insomnia, and a general feeling of being “out of kilter” are the typical signs of jet lag.
Altered melatonin levels appear to be a factor in numerous mood disorders, including depression, manic-depressive disease, and perhaps schizophrenia. There is even a clinical condition characterised by depression called hypomelatoninemia, or low melatonin syndrome, which can be improved by supplemental melatonin.
More recent research suggests a broader view of melatonin’s influence on the body clock, which begins ticking away at birth and slowly winds down as we age. In fact, melatonin plays a prominent role in the two predominant theories of ageing.
One well-accepted explanation for why we age is the free radical hypothesis, which theorises that free radicals – the byproducts of oxygen metabolism – cause accumulated damage to our cells, resulting in ageing. We know that free radical damage causes heart disease, cancer, cataracts and immune impairment, and other degenerative diseases. Exposure to free radicals over a lifetime leads to the breakdown of organs and functional processes.
In addition to the familiar antioxidants – vitamins A, C and E, and beta carotene – melatonin is also recognised as an extremely powerful free radical scavenger. It easily crosses the blood-brain barrier to protect the brain, which is exceptionally vulnerable to free radical damage. Melatonin has been shown to protect the brain in the aftermath of a stroke, and may be beneficial in neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and multiple schlerosis.
Melatonin may retard ageing on several fronts. As an antioxidant, it helps protect the brain, cardiovascular system and other systems from free-radical damage and age-related degenerative diseases. By boosting the immune system, melatonin guards against cancer and infectious diseases that are increasingly more prevalent as people age. Melatonin also plays a regulatory role in the endocrine system and boosts the production of growth hormone, the most remarkable anti-ageing substance yet discovered.
Melatonin is a “hormone” produced from the amino acid tryptophan by the pineal gland, a small gland in the centre of the brain. Very small amounts are also produced in the retina (eye) and gut.
Melatonin may significantly affect physical and psychological disorders such as:
Melatonin seems to operate independently of the complex orchestration that links the activity of the other hormones of the endocrine system. Mysterious and at home in darkness, its cue is the daily cyclic variation in light. While previous research has focused almost exclusively on melatonin's role in pacing the body’s day/night rhythms, new findings suggest it may exert potent anti-ageing effects.
Melatonin production has a circadian rhythm. Melatonin is responsible for maintenance of our daily biological rhythm and production is initiated by darkness, hence melatonin supplements should be taken at night.
Many of life’s most common occurrences – job, travel, stress, ageing – cause changes in sleeping patterns and are likely to have adverse effects on melatonin secretion patterns. Altered patterns and/or levels of melatonin secretion also coincide with the following medical conditions:
Melatonin production normally peaks around the time of puberty and then decreases with age. The most rapid decline usually occurs after age 40. Melatonin production declines steadily with age. Since the rest provided by sleep may support regenerative processes, melatonin may thus indirectly retard ageing.
Melatonin does not interfere with a person’s memory or performance the next day (up to 40mg); no carry over-fatigue.
No negative side-effects in elderly, with their memory, concentration or motor control, up to 50mg/day.