Nighttime Breast Cancer Theory - NBC Right Now/KNDO/KNDU Tri-Cities, Yakima, WA |

Nighttime Breast Cancer Theory

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KENNEWICK, Wash. - A new study suggests women who are exposed to a lot of artificial light at night may be at a higher risk for breast cancer.

A university in Israel used satellite images from NASA to show areas that emitted more light at night, and then compared them to breast cancer statistics from the same areas.

Breast cancer rates in areas with the most light were as much as 60% higher than the darkest areas.

However, not all doctors agree with the theory.

"But one theory I would seriously think about would be the thought that the people living in more lighted areas are also more exposed to chemicals and other things in the environment so finding a cause and effect between the two would be difficult, but not impossible," said Kevin A. Weeks, D.O., Columbia Basin Hematology & Oncology.   

Medical experts said the nighttime cancer theory revolves around the body's need for darkness to produce melatonin, which is a hormone that appears to offer protection against cancer cells.  They said exposure to light like computer screens and fluorescent bulbs turns off the body's production of melatonin.