Light at Night Ups Cancer Risk

Apr 13, 2010
Turning on the light at night can interfere with the body clock and leads to changes in the cells that eventually increase the risk of developing cancer, a new study says.

Dr Rachel Ben-Shlomo of the University of Haifa in Israel and Professor Charalambos P Kyriacou of the University of Leicester in the UK revealed that artificial light affects cell division, which is closely linked to the circadian rhythm. During the study, two groups of mice were exposed to light for 12 hours and dark for 12 hours. One group of mice was also exposed to one hour of artificial light at night.

The results of the study showed that mice that were exposed to artificial light at night, had changes in the cells that are in charge for the circadian rhythm that regulates a variety of body activities. It was found that some of the genes affected were those that take part in the development and spread of cancer as well as those that fight cancer.

The previous studies by Dr. Ben-Shlomo showed that the molecules that form the so called biological clock or circadian rhythm of the cells communicate with the outside environment through light.

The new study points out the effect of artificial light at night on gene transcription. Scientists say that turning on artificial light may cause damage to cell division, which is a risk factor for cancer. They recommend that if a person, for example, needs to use the light at night to go to the toilet, he or she should avoid switching on the light, but instead use plug-in lights that glow. This might become a safer option for people, who have to get up at night.