When it comes to the human body, even the smallest of structures can have important functions. This is true of the tiny structure located between the two hemispheres of the brain known as the pineal gland. This gland which is only the size of a pea has the critical function of regulating circadian rhythms and the sleep wake cycle in both humans and animals. This tiny gland plays an important role in helping your stay alert and functional during the daylight hours while helping you “turn off” at night.
The pineal regulates circadian rhythms through the secretion of a hormone known as melatonin. During the daylight hours when you’re active, light is carried from the retina of the eye to the brain where it tells the pineal gland to turn off melatonin production. As darkness approaches and the light level drops, the pineal gland increases its production of melatonin which helps you ease into a blissful sleep state. The pineal gland also appears to regulate metabolic function to some extent as well as prevent sexual development from occurring too soon in children.
As it turns out, the pineal gland may play a role in protecting against certain diseases including cancer. Studies in animals have shown that removal of the pineal gland from female rats increases their risk of breast cancer, probably due to the lack of melatonin production. Supplementing animals without pineal glands with melatonin appears to slow down the rate of breast cancer growth.
Other evidence suggesting the pineal gland and melatonin are important in breast cancer prevention is the fact that women who work third shift schedules have been shown to have a higher incidence of breast cancer in some studies. Because these women sleep daylight hours, their melatonin levels are lower due to the presence of light which shuts down melatonin production by the pineal gland.
It’s been suggested that taking melatonin supplements may be helpful for reducing the risk of certain diseases, particularly cancer. This may be particularly important as people age since the pineal gland calcifies during adulthood which reduces melatonin production. Melatonin is thought to have anti-oxidant properties as well as the ability to stimulate the immune system. It’s also thought to play a role in slowing down the aging process. Although some people use melatonin supplements as a sleep aid and as a treatment for jet lag, it’s still not clear whether supplementation is as effective as natural melatonin produced by the pineal gland.
If you want to maximize the amount of melatonin secreted by your pineal gland, go to bed as soon after it becomes dark as possible. Sleep in a room with as little light as possible. Even the small amounts of light put out by a clock radio or a streetlight can reduce melatonin production and, theoretically, increase your risk of cancer.
The importance of the pineal gland has been recognized throughout history with the philosopher Descartes calling it the “seat of the soul”. The pea sized pineal gland illustrates the fact that even the smallest structures play an important role in regulating the machine we call the human body.