Betreff: Cancer danger
Von: Mobile phone mast network
Datum: Mon, 19 Jun 2006 20:58:01 +0200

Cancer Causes Control. 2006 May;17(4):515-23. Related Articles, Links
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Light during darkness and cancer: relationships in circadian photoreception and tumor biology.

Jasser SA, Blask DE, Brainard GC.

Department of Neurology, Light Research Program, Thomas Jefferson University, 1025 Walnut Street, Suite 507, Philadelphia, PA 19107, USA.

The relationship between circadian phototransduction and circadian-regulated processes is poorly understood. Melatonin, commonly a circadian phase marker, may play a direct role in a myriad of physiologic processes. The circadian rhythm for pineal melatonin secretion is regulated by the hypothalamic suprachiasmatic nucleus (SCN). Its neural source of light input is a unique subset of intrinsically photosensitive retinal ganglion cells expressing melanopsin, the primary circadian photopigment in rodents and primates. Action spectra of melatonin suppression by light have shown that light in the 446-477 nm range, distinct from the visual system's peak sensitivity, is optimal for stimulating the human circadian system. Breast cancer is the oncological disease entity whose relationship to circadian rhythm fluctuations has perhaps been most extensively studied. Empirical data has increasingly supported the hypothesis that higher risk of breast cancer in industrialized countries is partly due to increased exposure to light at night. Studies of tumor biology implicate melatonin as a potential mediator of this effect. Yet, causality between lifestyle factors and circadian tumor biology remains elusive and likely reflects significant variability with physiologic context. Continued rigorous empirical inquiry into the physiology and clinical implications of these habitual, integrated aspects of life is highly warranted at this time.

PMID: 16596305 [PubMed - in process]
----- Original Message -----
From: Mobile phone mast network
Sent: Monday, June 19, 2006 8:46 PM
Subject: [Masts] Cancer danger....

Sorry, forgot to add on page 9 in the Daily Mail, directly under the story of Prince William's girlfriend getting her own Tetra handset is an article saying that women who sleep with the light on or stay up late at night could be at a greater risk of breast cancer, according to scientists.
"Researchers have long suggested that being exposed to too much light at night disrupts crucial hormones and raises the chance of developing breast tumours.
....The study was conducted by scientists from the American National Cancer Inst. and National Inst. of Environmental Health Sciences.........................................
The reseach by the American scientists showed that exposure at night to artifical light could stimulate the growth of human breast tumours by suppressing the levels of the key hormone melatonin.  Melatonin is secreted by the pineal gland at night and helps to regulate a person's sleeping and waking cycles.  Light, however, stops the body from producing it, making the body think that is daytime.  The researchers proved the theory by grafting human breast cancer tumours on to rats.  Blood samples from women were them pumped through the developing tumours.  ......the blood taken after exposure to light appeared to stimulate tumour growth.  Dr. David Blask, a lead researcher on the study, said it was "the first proof that light is indeed a risk factor for cancer.  Evidence is emerging that 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."
.....Professor George Brianard of the Thomas Jefferson University in Philadelphia, added "Humans evolved on a planet without electric light over thousands of thousands of generations.  The body is designed to be alert and awake during the daytime hours and to sleep at night.  Now we have a 24-7 society that isn't in harmony with our biological design."
As so many of us are suffering from emissions from masts, etc., and unable to sleep throughout the night - where does that leave us?  Interesting that Melatonin is mentioned, Roger as this obviously is one that you would know a lot about, as would Gary and others interested in nutrition. 
Regards, Vivienne