Melatonin Production and Age
It is not only fact that modern man is the only organism that deviates from its normal rhythm and makes day out of night, but it is also true that the older we get, the smaller the amount of nightly melatonin production becomes. Because of this, the nightly signal becomes shorter, which is a change that is passed on to the entire body. Often the signal is not activated until long after midnight. However, the secretion of the hormone ceases punctually at daybreak. This results is elderly people receive the sleep hormone for a time period that is far too short, making it less and less available. For older pineal glands, a sufficient melatonin production in the night is no longer possible, even if the body finds itself in complete darkness. The pineal gland is supplied with large amounts vessels, which with age are calcificated, much like other regions of the body. Calcification can lead to a reduction in melatonin production and with it a pronounced loss of sleep and disruption of circadian rhythm.
Until the third month of life, melatonin is hardly produced according to a day/night rhythm. After this, the nightly serum melatonin values increase, resulting in a gradual development of a circadian cycle. Between the first and third year of life the highest production of melatonin is reached. These high levels are maintained until puberty, after which it begins to fall to average adult levels. A healthy human adult has a melatonin level that is 8-10 times higher at night, as opposed to in the elderly where this value only rises very late and for a brief time to twice that of the daily level. This low day/night difference is no longer sufficient to relay the change from day to night correctly or regulate the inner clock. It is possible that this is a reason for the frequent complaints of sleep disturbances and its related illnesses among the elderly.
Lack of melatonin also makes itself evident in the disrupted rhythm of hormone systems that are downstream. An early reduction in melatonin production can be a factor of the early onset of menopause, as it also leads to the reduction in sex hormones. Melatonin is also essential for the production of the growth hormone HGH, also called the “vitality hormone,“ as the production is slowed if melatonin is lacking. Insufficient melatonin also impacts the liver, causing ineffective programming for the night. This can lead to insulin resistance, which can eventually lead to diabetes. Additionally, the urge to urinate remains the same in the night as during the day if a specific anti-hormone (ADH) is missing due to melatonin deficiency.
Melatonin deficiency also has a significant impact on the brain. All of the nightly repair mechanisms are reduced. Saving of information for long term memory, which occurs at night, is no longer supported. This increases the susceptibility for early onset dementia and neurodegenerative processes.
The professional British Magazine, Journal of Ophthalmology, recently published an alarming correlation between aging eyes and melatonin production. Measurements show that after the age of 45, fewer sunrays reach the inner eye. This is the result of the slight yellowing of the ocular lens and the narrowing of the pupil. For this reason, fewer light particles reach the important cells of the retina, which measures the day/night rhythm in order to regulate our inner clocks. Studies show that changes in the aging eye can lead to a number of typical eye diseases, for which the cause is not found in the eye itself. The consequences of the deterioration of eye capacity include cognitive deficiencies (especially memory capacity), sleeplessness, depression and delayed reaction times. Due to these facts, a correlation between eye changes and disrupted melatonin production are postulated. Our inner clocks react to the changes between light and dark and control our daily rhythm. They give each organ an impulse for its day-time and night-time functions. The brain, for example, stores the information obtained throughout the day into long-term memory, or deletes it entirely. These ignition signals are frequently transmitted through the mother hormone of chronobiology: melatonin. Elderly people only have a fraction of the needed hormone level available to them, which in turn, impacts the concentration of other neurotransmitters. This leads not only to widespread problems with sleeping through the night, but also to an impairment of the actual daytime activities of the most important organs, for example of the liver or nerves, in the course of a 24-hour day.