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: New clinical trial launched for advance lung cancer

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

New clinical trial launched for advance lung cancer

6 minutes ago

Cancer Research UK is partnering with pharmaceutical companies AstraZeneca and Pfizer to create a pioneering clinical trial for patients with advanced lung cancer – marking a new era of research into personalised medicines ...

User comments : 0

More news stories

Down's chromosome cause genome-wide disruption

The extra copy of Chromosome 21 that causes Down's syndrome throws a spanner into the workings of all the other chromosomes as well, said a study published Wednesday that surprised its authors.

Simplicity is key to co-operative robots

A way of making hundreds—or even thousands—of tiny robots cluster to carry out tasks without using any memory or processing power has been developed by engineers at the University of Sheffield, UK.

Progress in the fight against quantum dissipation

(Phys.org) —Scientists at Yale have confirmed a 50-year-old, previously untested theoretical prediction in physics and improved the energy storage time of a quantum switch by several orders of magnitude. ...