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Melanoma & Melatonin

Jul 14, 2011 | By Tomas Linnaeus
Melanoma & Melatonin
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Melatonin plays an important role in many processes throughout your body. This hormone, released nightly by the pineal gland, regulates biological rhythms and improves sleep quality. It also contributes to the immune system by preventing a broad range of diseases, including melanoma. This type of skin cancer continues to increase despite advances in treatment and education. Large doses of melatonin kill melanoma cells and melatonin supplements may eventually prove useful in fighting cancer, according to an April 2003 report in "Melanoma Research." Speak to your doctor before taking nutritional supplements.

Increasing Melatonin Decreases Melanoma

Scientists can keep skin cancer cells alive in a special dish. Adding melatonin to this dish allows them to study the relationship between the hormone and the melanoma. An experiment described in the August 2010 issue of the "Journal of Pineal Research" used this procedure and showed that melatonin prevented the growth of cancerous cells. The study did not reveal the underlying mechanism, but tests in laboratory animals have produced similar data. An April 2008 report in that same journal evaluated the effect of melatonin on mice with skin cancer. Rodents given melatonin for a year had smaller tumors, and they showed less cancer proliferation. A clinical trial offered in the November 1996 edition of the "Journal of Pineal Research" confirmed these results in human subjects. Melanoma patients receiving nightly doses of melatonin for several years were more likely to be disease free than those given no treatment.

Decreasing Melatonin Increases Melanoma

Manipulating melatonin levels and then measuring the impact this change has on melanoma provides another approach. Most circulating melatonin comes from the pineal gland located deep in your brain. A June 2010 article published in the journal "Sleep" showed that removing this gland reduces the amount of melatonin present in the bloodstream. This surgery -- known as pinealectomy -- increases the proliferation of grafted melanoma cells, according to an August 1983 report in "Endocrinology." The authors of this study found that pinealectomized hamsters had larger tumors than those with intact pineal glands.

Decreasing Melatonin Increases Melanoma Risk

Your work environment can also affect your melatonin production. Bright light quickly decreases circulating levels of the hormone, according to a 2011 report in "Neuroendocrinology Letters." Most work environments contain sufficiently bright light to achieve this effect, and people regularly exposed to light at night may be more likely to develop melanoma. An experiment presented in the March 2000 edition of "Occupational and Environmental Medicine" tested this hypothesis in airline pilots. Transcontinental trips require airplanes to achieve heights associated with high intensity light, and pilots are often exposed to this light during their subjective night. In the study, pilots were shown to have an unusually high incidence of melanoma.

Having Melanoma Affects Melatonin Production

Measuring melatonin levels in patients with melanoma also reveals an association between these two factors. People with eye cancer -- a rare form of melanoma -- have large quantities of melatonin, according to a December 2003 paper in "Clinical and Experimental Ophthalmology." This increase likely results from a reduced amount of light transmission from the eye to the brain in these patients. An analysis published in the 1986 volume of the "Journal of Pineal Research" assessed melatonin levels in patients with other types of melanoma. Relative to controls, women and men with skin melanoma had lower amounts of urinary melatonin.

References

Article reviewed by J.A. Rist Last updated on: Jul 14, 2011

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