Can Nighttime Trips to the Bathroom Really Lead to Cancer?

[Dr. Chapa Kiuno]

Getting up in the middle of the night to urinate may cause more problems than simply interrupting a good night's sleep. It could also lead to cancer -- that is, if you turn on the light, according to the Daily Mail.
Various news outlets are reporting that researchers from the UK and Israel claim that even a quick bout of light in the middle of the night can trigger an 'overexpression' of brain cells linked to cancer. However, the new study's lead author, Charalambos P. Kyriacou, told AOL Health that cancer risk only increases with prolonged light exposure.
"A quick switch on of the light will have negligible effects -- we are talking about prolonged bright light exposure at night," Kyriacou, professor of behavioral genetics at the University of Leicester, explained. "The 'switching on of lights causes cancer when you go to the bathroom at night' is an eye-catching fabrication of the press."
In the study, Kyriacou and his colleagues exposed mice to bright light for one hour to mimic how shift workers may respond to prolonged light. Then, they examined the mice's genomes, or DNA sequences, for changes in certain genes' activity during the light burst. One group of genes that illustrated a change in activity were those responsible for the cell cycle, or the process by which cells divide and multiply, Kyriacou said.
Previous studies have shown that chronic shift workers suffer from physical and cognitive problems, including increased risk of cancer. This study illustrated that the cell cycle genes' change in activity may cause these health issues.
"I think our work tells people what is already out there in the literature, that shift workers have higher risks of developing illnesses, including cancer," Kyriacou explained. "It suggests a possible mechanism."
Dr. Anish Sheth, assistant professor of medicine at Yale University School of Medicine and co-author of "What's My Pee Telling Me?" (who had no affiliation to the study) said that previous research has shown that getting up in the middle of the night can lead to health problems by causing changes in melatonin, the hormone that regulates sleep and wake cycles.
Sheth believes that people should be more concerned with waking up in the middle of the night than turning on the lights, as keeping the lights off can lead to more accidents.
"It's definitely an interesting study, but I think it's premature to recommend that you shouldn't turn on the light at night," Sheth says.