In part 1 of this blog I introduced the concept of melatonin being much more than a sleep aid which normally is this hormone's primary therapeutic application as a supplement. The main focus in part 1 was melatonin's utility in gastrointestinal health and its role as a potent antioxidant. In this next installment we will look at melatonin's potential role as an anti-aging compound and its impact on the immune system including its possible role in cancer.

Research has demonstrated a distinct relationship between the neuroendocrine and immune systems. This is illustrated by the existence of a feedback loop in which the endogenous compounds produced by the neuroendocrine system act on the immune system while the immune system then responds to this information communicating back to the neuroendrocrine system through this feedback loop. For instance both systems produce common compounds like ACTH and acetylcholine which reinforces this notion. Melatonin is part of this communication network.

Cancer-Protective

Regarding cancer it appears that melatonin displays both anti-cancer and cancer-protective properties through various mechanisms of action including its functions as an antioxidant a cell signaling agent a regulator of gene expression and an immune stimulant among others.

Melatonin secretion is impaired in patients suffering from breast cancer endometrial cancer prostate or colorectal cancer. Not surprisingly then it follows that the increased incidence of breast and colorectal cancers seen in night shift workers and the elderly suggests a possible link between diminished secretion of melatonin and increased exposure to light during nighttime or perhaps simply age-related disturbances in circadian rhythm which may be directly related to a reduced capacity to produce melatonin as we age.

Immune Support

Depressed melatonin production has also been shown to adversely affect the production of B lymphocytes a variety of immunoglobulins T cells NK cells neutrophils and macrophages. Repletion of melatonin has been shown to augment the production of these important immune cells thus having an impact on both innate and acquired immunity. Melatonin performs this function through a variety of mechanisms including activation of immune receptors found on immune organs associated tissues and stem cells. Melatonin increases monocyte sensitivity to various cytokine stimulants as well.

Again as we age like most hormones melatonin production declines which may be one reason the elderly experience a significant deterioration in their immune response and ability to fight infections. Does this imply the necessity of regular consistent melatonin supplementation in the elderly?

Antioxidative and Neurorotective Properties

Melatonin's impact on other areas of physiology may also provoke some interest. For instance as mentioned earlier melatonin possesses potent antioxidative properties as it has been shown to up-regulate the production of the enzymes glutathione peroxidase and super oxide dismutase. It is this trait that was found to decrease the oxidative stress caused by long-term cell phone use while also protecting tissue against gamma radiation exposure.

Melatonin supplementation also appears to be protective of the brain. Its antioxidative properties decrease levels of brain-damaging amyloid proteins as well as up-regulate pro-survival genes in mouse models of aging which demonstrate the neurohormone's potential as an anti-aging compound. Additionally melatonin has been shown to reduce and improve age-related skinchanges.

Finally melatonin may not only be neuroprotective but it has also been shown to up-regulate genes responsible for neurogenesis an important mechanism in the recovery of brain injury due to stroke for example.

Like many compounds melatonin may be in a class that possesses a variety of beneficial properties that many of us may not be aware of and should possibly consider when developing our various treatment protocols.

Michael Fuhrman D.C.