The pineal gland was called the "third eye" by ancient people. It was thought to have mystical powers. This may be why the French philosopher Descartes decided that the pineal gland was the seat of the human soul, the location of what we call the mind. The pineal does contain a complete map of the visual field of the eyes, and it plays several significant roles in human functioning.
Also called the pineal body or epiphysis cerebri, the pineal gland is important to this discussion for two reasons. First, it is the center for the production of the hormone melatonin. Melatonin is implicated in a wide range of human activities. It regulates daily body rhythms, most notably the day/night cycle (circadian rhythms). Melatonin is released in the dark, during sleep. The recent melatonin craze sweeping through the health conscious community makes claims that the hormone slows the aging process (a defense against free radicals), prevents jet lag, is implicated in seasonal affective disorder, coordinates fertility, and allows for deep restful sleep patterns.
Melatonin is a very ancient hormone that is found throughout the animal kingdom. In reptiles and birds the pineal is close to the skin and needs no interaction with the eye to register day/night cycles (this is where the notion of the 'third eye" comes from). In these animals, the pineal gland is the master clock. In mammals, however, the pineal gland is subordinate to the eye/SCN system. Light severely curtails the production of melatonin.
Melatonin has been shown to inhibit the growth and metastasis of some tumours in experimental animals, and may therefore play a role in cancer inhibition. Removal of the pineal gland and/or reduction in melatonin output have been implicated in the increased incidence of breast cancer in laboratory animals. Patients who have breast cancer have lower levels of melatonin in the blood. The hormone has also been shown to be protective against genetic damage, and it has a stimulatory effect on the immune system.
The anticancer role of melatonin in humans is not established yet, but in a study involving blind women, melatonin production was found to be higher at all times. This finding was associated with the finding that breast cancer in this study was correspondingly lower for these blind women compared to the general population.
The pineal gland has been implicated in a number of disorders including cancer, sexual dysfunction, hypertension, epilepsy, and Paget's disease. The pineal gland calcifies with age and melatonin production correspondingly decreases. This decline in melatonin has been suggested to be a trigger for the aging process.
Environmental stresses affect pineal function, impacting overall body alertness, temperature levels, and hormone operation. Stresses that affect pineal function include unusual light and dark rhythms, radiation, magnetic fields, nutritional imbalances, temperature swings, high altitude, and overall daily stress patterns. (Read More)
