It is clear that any substance in the body has a function for full and healthy life of the human being. It is also clear that when these substances are beginning to dwindle in the body appears the aging, disease, and other undesirable things. This article will talk about an almost magical substance that is produced by the body, specifically by the pineal gland: melatonin. And talk about melatonin not in its role in relation to the good sleep, either in their role against aging. This time we will talk of melatonin in their relationship with cancer. And it is that numerous studies have focused on the fundamental role of this hormone in prevention, development and treatment of this disease.

And studies seem to indicate that low levels of melatonin are associated with an increased risk of breast cancer, hence the importance of maintaining a good level of melatonin at night, respecting the circadian rhythm and suplementandola if this is not enough. In night work, exposure to artificial light, which inhibits the secretion of melatonin, with the consequent disruption of the circadian rhythm with the body which works to be on the basis of that collective as night shift nurses present a greater risk to develop this disease. Different hypothesis, a part that the lack of melatonin, which is the largest natural antioxidant, prevents to protect DNA from cell damage that can lead to cancer are postulated. And on the other hand, the rupture of the circadian rhythm of melatonin secretion causes serious sleep problems, since not resting equally during the day, weakening the immune system making them more prone to disease. In countries as Denmark is association between breast cancer and night work has carried the country to consider it an occupational disease and to compensate women affected since 2009. There are many experimental studies in which through cancer induced in animals, as well as in Vitro experimentation on human mammary cells conveyed cancer, melatonin has proven to be a substance with oncostaticos, i.e.