Study says night light may promote cancer

Jun 29, 2006

A New York researcher says frequent exposure to artificial light at night may increase the risk of breast cancer.

In a study reported in the current issue of the American Journal of Epidemiology, Dr. Cristina Leske of Stony Brook University questioned 576 Long Island women who developed breast cancer, and 585 who never had the disease, to determine whether exposure to artificial light plays a role, Newsday reported.

A subset of women who had developed breast cancer tended to wake up frequently during the night and turned on lights during what should have been hours set aside for sleeping, Leske said.

At night, the hormone melatonin streams into the bloodstreams and flows throughout the night, suppressing cancer cells. Melatonin is switched off -- and estrogen switches on -- by the presence of light.

Leske concluded that the positive association of night lights with breast cancer was 65 percent. However, among overnight shift workers, Leske found a 45 percent lower breast cancer risk.

She said the results suggest that shift workers somehow altered their circadian clocks, so their hormone flow adapted to their work schedules, the newspaper reported.

Copyright 2006 by United Press International

Explore further: Critically ill ICU patients lose almost all of their gut microbesand the ones left aren't good

add to favorites email to friend print save as pdf

Related Stories

Shift work and cancer

Oct 08, 2010

Shift work can cause cancer. In the new issue of the Deutsches Arzteblatt International (Dtsch Arztebl Int 2010; 107[38]: 657-62), Thomas C. Erren and colleagues describe the current state of knowledge in this area and po ...

SKorea says Samsung chip plant caused cancer

Dec 14, 2012

(AP)—A South Korean government agency said Friday that working at a Samsung Electronics factory caused the breast cancer of a worker who died earlier this year, only the second time it has recognized a link between cancer ...

Recommended for you

We drink more alcohol on gym days

7 hours ago

A new Northwestern Medicine study finds that on days when people exercise more—typically Thursdays to Sundays—they drink more alcohol, too.

Sierra Leone, Liberia brace for new Ebola cases

8 hours ago

Two of the West African nations hardest hit by Ebola were bracing for new caseloads on Monday after trying to outflank the outbreak with a nationwide checkup and a large new clinic.

User comments : 0