MELATONIN

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, via the optic nerve and the central nervous system, and uses those light signals, or lack of them, to regulate our circadian rhythms.  The word circadian comes from the Latin circa (about) and dies (day), and pertains to events that occur at about 24-hour intervals.  Commonly called our body clock, this is what lets us know when to sleep and when to wake.

Melatonin Influences More Than Your Sleep/Wake Cycle

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 aging.

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, because its production is dependent on enzymes in the pineal gland activated by darkness.  The level of melatonin secretions begins to rise at nightfall and continues to climb until it peaks from 1am to 5am and then tapers off.  This cycle is repeated every 24 hours.

For many years, melatonin research focused on these daily rhythms, the sleep/wake cycle, and its disruptions.  The evidence for melatonin’s role in sleep is undisputed.  Blind people often have sleep problems, which may well be due to suppressed melatonin levels as well as to an inability to perceive differences in light and darkness.  Sleep difficulties are common among the elderly, whose melatonin levels are diminished.  Early sleep research with melatonin used hight doses of the hormone, up to 240mg, which made the test subjects sleep well, but they felt extremely groggy the next day and were unable to function.  Follow up studies showed that much lower doses, less than 1/100 of that dose, were sufficient to aid 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.

Vanquish Jet Lag

Other conditions related to circadian rhythm respond well to melatonin.  One thing that evolution did not prepare us for was jet lag.  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.

A 1986 study published in the “British Medical Journal” studied the effects of melatonin on 17 healthy people travelling from San Francisco to London.  For three days before their departure, eight of the subjects were given 5mg of melatonin at 6pm, California time.  Upon arrival in London they continued taking 5mg per day at 10am to 12pm, England time.  The other nine subjects took a placebo.  They were asked to evaluate their symptoms of jet lag over the next few days.  Six of the nine subjects on the placebo rated jet lag as over 50 on a scale of 1 to 100, with 100 being the worst.  None of the eight subjects on melatonin rated their jet lag as worse than 17.

Melatonin Ushers in the Winter Hibernation Instinct

Your body rhythms are influenced by other, longer cycles, in addition to day and night.  Cued by decreasing hours of daylight, melatonin secretion begins earlier and lasts longer during the winter months.  It is melatonin’s response to this decrease in light that ushers in hibernation in some animals.  Its opposite effect provides springtime’s impetus for most animals to mate and reproduce.  We “highly evolved” humans may consider ourselves immune to such primal forces but, in fact, it is because of our supplies of melatonin that most of us adjust well to these changes in the seasons and aren’t even aware of the subtle adaptations going on in our bodies.

For an unfortunate few, however, the shorter days of fall and winter bring with them feelings of depression, fatigue, sleepiness and often carbohydrate cravings with resulting weight gain.  This is known as seasonal affective disorder (SAD), and it affects perhaps 1% of the population, most of them in the northern climes.

SAD is clearly caused by an alteration in the circadian rhythm, and the most effective treatment includes supplemental melatonin at bedtime and exposure to full spectrum light, which is extremely close to natural sunlight, for periods during the day.  Light re-establishes the circadian rhythm by reinforcing the light/dark cycle and stimulating the production of melatonin.  Symptoms can be relieved within a few days on this treatment program.

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.

Melatonin Has Life Extending Potential

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 aging.

One well accepted explanation for why we age is the free radical hypothesis, which theorises that free radicals (the by-products of oxygen metabolism), cause accumulated damage to our cells, resulting in aging.  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. 

We also know that antioxidants counteract free radicals and stop or limit the damage they cause.  This is why I recommend antioxidant vitamin and mineral supplements so strongly.

In addition to the familiar antioxidants (vitamins A, C, E and beta carotene) melatonin is also recognised as an extremely powerful free radical scavenger.  Unlike most other free radical fighters, melatonin is both fat and water soluble, so it protects all parts of the cell including DNA.  Melatonin is at least twice as effective at protecting fatty cell membranes as vitamin E, five more times powerful than glutathione in neutralising highly damaging hydroxyl radicals, and 500 times better than DMSO at protecting cells from radiation.

Melatonin also boosts the immune system by facilitating the actions of T-cells, particularly T-helper cells, which “coordinate” the immune response.  Thus helping stimulate the production of natural killer cells (which attack cancer cells and viruses), phagocytes and granulocyte-macrophage colony-stimulating factor (GM-CSF), which signals the bone marrow to produce more disease fighting white blood cells).

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 sclerosis.

Melatonin may retard aging 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 aging substance yet discovered.

A second well know explanation of aging is the biological clock theory.  This stipulates that aging is a result of a lifelong genetic program controlled by the central nervous, endocrine and immune systems.  As we grow older, our pineal glands create less and less melatonin, blurring the once clear gradation between daytime and nighttime production.  The theory contends that this blurring causes a disruption of the pineal gland’s regulatory functions in the body resulting in a decrease in antioxidant production and weakening of the immune system.  This chain of events contributes to degenerative disease and eventually death.

To examine this premise, Italian researcher Walter Pierpaoli, M.D. Ph.D, grafted the pineal glands of young mine into the thymus of old mice, and vice versa.  The older mice that got young pineal glands began to look and act young, and their life span increase by 12 percent.  The younger mice that got old pineal glands aged rapidly and died prematurely.

Among the latest melatonin research is its therapeutic effects on metastatic cancer.  Paolo Lissoni M.D and a team of Italian researchers have explored the use of higher doses of melatonin (10 to 40mg) and /or injected melatonin in cancers of the lung, colon, rectum, stomach, brain and breast.  Although melatonin did not cure cancer, it led to tumour shrinkage, increased survival time and enhancements to quality of life.

Melatonin is known to stimulate the immune system.  In addition, it may inhibit cancer growth factors and attack tumour cells.  Whatever its mechanism, melatonin is a safe, inexpensive therapy that merits further exploration in advanced cancer.

Taken Judiciously, Melatonin Is Safe

Is melatonin dangerous?  Taken in small doses, absolutely not.  Even at very high doses it has been shown to have no toxicity.  Doses as high as 6.6 grams daily for a month have been tested, as well as 250mg daily intravenously, with no reports of short or long-term toxicity.

On the other hand, a low percentage of people taking melatonin (perhaps 5%) report having bad dreams or nightmares, and a few more feel groggy in the morning.  In animal studies, administration of melatonin has been noted to lower testosterone production and even shrink the testicles of animals given higher doses.  Because it stimulates the immune system, it may have adverse effects in people with conditions involving the immune system such as lupus, rheumatoid arthritis, multiple sclerosis, lymphoma or leukaemia.  These adverse links are, at this point, weak, but I would not advise taking melatonin if you have one of these diseases until further research clarifies this issue.