--- The Fool <[EMAIL PROTECTED]> wrote: > http://www.cnn.com/2003/HEALTH/conditions/06/04/cancer.nightshifts.reut/ > > Nurses who work regular night shifts have a higher > risk of colon cancer, > a study found, suggesting a relationship between the > amount of sunlight exposure and the cancer. > > The study by researchers at Harvard Medical School > and Brigham and > Women's Hospital in Boston supports earlier research > that found women who > work night shifts have a higher risk of breast > cancer. > > "Because night-shift work has become very common in > developed countries, > future studies should assess the relationship of > light exposure to the > risk of other cancers and consider the risks in > men," they wrote...
It probably isn't so much the lack of sunlight as it is the excess of artificial light, which decreases the ~1AM production of melatonin (although lack of sustained bright light is connected to depression and I think some other neurochemical problems). http://my.webmd.com/content/Article/66/79657.htm?printing=true "...During the dark nighttime hours, the body produces a hormone called melatonin, "which is also called the hormone of the dark," Schernhammer says. "The peak production of melatonin occurs at about 1 or 2 a.m." Exposure to light at night stops the production of melatonin. "In animal experiments and in some laboratory studies, melatonin demonstrated the ability to protect against the development of cancers, and several researchers suggest that it works the same way in humans, says Schernhammer..." There has also been research suggesting that too much light at night causes retinal damage (the level was roughly 'if you can read by it, it's too bright'). I wonder if taking supplemental melatonin (at the person's 'bedtime') would correct the deficit? And since we know that melatonin production decreases with age (that's why, as a sleeping aid, 1 mg tends to work better for older folk; I tried it when I was doing shift work in residency, but it didn't seem to help my sleep at all), is it a factor in cancer occurence? And what about those of us who keep bizarre hours anyway; will our cancer risk be higher? Hmm, better keep those multivitamins and fresh veggies coming... Debbi whose own sleep cycle used to be 1 or 2AM to 10AM, but having had to adapt, it's now just non-regular :P __________________________________ Do you Yahoo!? Yahoo! Calendar - Free online calendar with sync to Outlook(TM). http://calendar.yahoo.com _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
