NIGHT SHIFT INCREASES RISK OF BREAST CANCER? This is not the first study to find links between melatonin levels and breast cancer. If you look at a “light map” of the US, the areas with the most light at night have the highest rates of breast cancer. It is highly likely that this relates to the production of melatonin. Melatonin is produced deep in the brain in the pineal gland, but it’s production is shut down by light striking the retina. Helps set our sleep / wake cycles.
So, staying inside all day long (not getting strong sunlight exposure) or staying up late at night can mess with our body’s production of melatonin. The current thought is that melatonin has some powerful antioxidant properties, and this may be a mechnism by which it protects our genes from cancer.