Melatonin

[john]

There was a clinical trial of melatonin and brain mets - not sure of the results. Dr weil does not advice LONG term use of any hormone, like melatonin.

Melatonin and cancer risk: does light at night compromise physiologic cancer protection by lowering serum melatonin levels?

E S Schernhammer1,2 and K Schulmeister3

1Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA

2Ludwig Boltzmann-Institute for Applied Cancer Research, KFJ-Spital, Vienna, Austria

3ARC Seibersdorf research, Health Physics Division, Seibersdorf A-2444, Austria

Correspondence to: Dr ES Schernhammer, Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA. E-mail: eva.schernhammer@channing.harvard.edu

Received 9 October 2003; revised 3 December 2003; accepted 5 December 2003

The suprachiasmatic nuclei in the hypothalamus, one of the most important physiological determinants of alertness and performance, drive a circadian pacemaker in mammals, with an intrinsic period averaging 24 h. Light is the primary stimulus to the disruption and resetting of this pacemaker, which is expressed in changing melatonin rhythms. Melatonin production in humans decreases when people are exposed to light at night. Since melatonin shows potential oncostatic action in a variety of tumours, it is possible that lowered serum melatonin levels caused by exposure to light at night enhance the general tumour development. Cancer is the second leading cause of death in industrialised countries like the United States, where a significant proportion of workers engage in shift work, making a hypothesised relation between light exposure at night and cancer risk relevant. Observational studies support an association between night work and cancer risk. We hypothesise that the potential primary culprit for this observed association is the lack of melatonin, a cancer-protective agent whose production is severely diminished in people exposed to light at night.

[Elaine]

So llike sleeping with the lights on is a cancer risk?

[Snowflake]

I don't think so, Elaine...BUT, it would seem to me if all that stuff were true, there'd be a higher incidence of cancer in people living in northern Canada and Alaska - that "Land of the Midnight Sun" thing that REALLY screws up the ol' body clock....

..and sometimes "answers" bring more questions...

[Elaine]

I know, lol, I know.

[john]

Yes it is just one hypothesis ... But it is interesting that it is from Harvard.

Maybe it is not the light but the stress from not getting proper sleep.

http://www.uni-koeln.de/symposium2000/c ... tracts.pdf