New research is showing that exposure to dim light at night may negatively impact the effectiveness of breast cancer treatments. In a laboratory setting, dim light exposure during night cycles made human breast tumors in rats more resistant to doxorubicin, a standard chemotherapy for breast cancer.
But why? Well, it’s all about melatonin. Melatonin is a hormone that is produced naturally by the body during dark periods at night. In this research study, exposure to light at night disrupted rats’ melatonin cycles. Half of the rats, however, received melatonin supplements to make up for this. Researchers found that the tumors grew almost three times faster in rats that did not receive supplements, and their tumors were completely resistant to doxorubicin. It seems that the presence of melatonin helped support higher levels of active doxorubicin in the breast cancer cells, and prevented enzymes from breaking it down and making it less effective.
At this point, researchers aren’t ready to make supplementation recommendations for human breast cancer patients. And if the effects of melatonin ARE similar in humans, recommendations for supplementation would need to be carefully monitored. If disrupting the natural melatonin cycle can cause the body to react to cancer treatments differently, then incorrectly supplementing could also cause undesired effects. However, since this isn’t the first time that dim light exposure at night has been shown to have negative effects, it’s possible that this research could prompt patients to be more aware of light exposure disruptions during night cycles.
Read more about it here: http://www.aacr.org/Newsroom/Pages/News-Release-Detail.aspx?ItemID=608#.VC9VpPldWSo