Scientists at the Tulane University School of Medicine in the United States have found that light exposure could affect sleep hormones and consequently alter cancer cell function.
Animal study reveals that light plays significant role in making toumors become resistant to the widely used cancer medicine, Tamoxifen, according to the report published in the journalCancer Research.
While the light affects body clock and sleep hormones, it can cut Tamoxifen's working through violating hormones' functions.
The medicine stops the female hormone oestrogen fuelling the growth of tumors although the cancerous cells may eventually become resistant to the drug.
Scientists focused their research on the sleep-promoting hormone melatonin, which normally begins to rise in the evening and continues through the night, before falling away as dawn approaches.
They observed two groups of Rats, with human breast cancer and treated with Tamoxifen, including one group left to sleep in a completely dark cage and one that had dim light.
The results unveiled that in dim light, melatonin levels were lower, the tumors were bigger and were resistant to Tamoxifen.
"People could make sure they sleep in a room that is completely dark or they could wear eye-masks to let night-time melatonin rise and take Tamoxifen right before going to bed, that would be the easiest way to see if it works," said the researcher Dr Steven Hill.
"The team is planning to move the research into human breast tissue," he also announced.
"Light is disrupting the body clock, which stems from our evolutionary past when we were active when it was light in the day and resting when it was dark at night," researchers say.
Earlier studies demonstrated that light through disrupting the body clock could increase weight gaining and obesity risk in women.
Light also affects on mood, physical strength and even the way of processing food in a 24-hour cycle.
Loss of power plants via natural catastrophes and darkening of skies via volcanic eruptions & heavy cometary dust will inevitably gift humans with lots of darkness. Except sunlight will be then scarce commodity..