June 20, 2006
Too much night light raises breast cancer riskTopics: Health Issues
Melatonin exerts a strong influence on the body's circadian rhythm, an internal biological clock that regulates sleep-wake cycle, body temperature, endocrine functions, and a number of disease processes including heart attack, stroke and asthma. It has also been suspected to have potential oncostatic activity and is acutely suppressed by light exposure. Evidence suggests an association between night work and breast cancer risk, likely via the melatonin pathway.
Now a new study suggests that this could to some extent explain the rising levels of breast cancers in rich countries, where the risk of developing cancer is five times higher than in underdeveloped countries.
... The study by American National Cancer Institute and National Institute of Environmental Health Sciences demonstrates that artificial light increased the risk of developing breast cancer by inhibiting the levels of the key hormone melatonin.
... Melatonin is secreted by the pineal gland and this secretion takes place, in the main, at night.
... The hormone regulates sleeping and waking cycles and it appears that the presence of light suppresses the production of the hormone.
... more evidence is emerging that the disruption of a person's body clock is associated with cancer in humans, and that interference with internal timekeeping can tip the balance in favour of tumour development.
... If the link between tumour growth and light is confirmed by more studies a change in working patterns may be seen and lighting manufacturers forced to develop products which are more natural and similar to normal daylight.
As discussed in the article, melatonin is produced at night, and released into the blood stream where it is dispersed throughout the body. Once in the blood stream, melatonin has access to every cell in the body, and passes through the cell membranes where every nucleus has receptors for it.
Melatonin is believed to have at least six fundamental physiological functions:
* mediating the whole-body 24 hour circadian rhythm;Because melatonin is a potent hormone, it's advisable to check with a healthcare provider before using it as an antioxidant supplement, an adjunct to cancer treatment, sleep aid, or any other use, it's advisable to FIRST check with your physician.
* regulating sleep, mood and behavior like depression, anger and rage;
* scavenging free radicals (highly reactive cancer promoting agents);
* reduce secretion of tumor-promoting hormones;
* regulating gene expressions;
* protecting and stimulating the immune system.
Melatonin Supplementation - uses, Possible Interactions.
Artificial Light At Night Stimulates Breast Cancer Growth In Laboratory Mice (Updated with links)
THE PHOTOPERIOD TRANSDUCER MELATONIN AND THE IMMUNE-HEMATOPOIETIC SYSTEM
Bright Lights, Big Cancer
Posted by Richard at June 20, 2006 7:01 PM
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- Too much night light raises breast cancer risk - Jun 20, 2006