Adequate and quality sleep are critical to the healing process. Inadequate and inconsistent sleep cause circadian disruption which is associated with an increased breast cancer risk (Rabstein, 2014).
Lack of sleep over time (less than six hours a night) has been noted to increase the risk of breast cancer by 62 percent. Sleep is important in regulating melatonin, an antioxidant that provides protection from breast cancer (Malina, 2013). When we sleep deeply, our endocrine system can recharge, which involves the nocturnal pineal production of melatonin.
Sleep with the natural light which means getting to bed early in a dark cool and quiet space. Make sure to block the outside light and that there are no lights visible, even small ones such as tiny lights on the TV or on an alarm clock. Researchers found that even dim light at night interrupts circadian cycles and suppresses melatonin.
Lack of melatonin can lead to hyperglycemia (high blood sugar), hyperinsulinemia, lipid signaling, and tumor growth (Blask, 2014). A disruption in circadian sleep cycles alters core body temperature, hormone regulation and patterns of gene expression throughout the body (Steven, 2015).
Melatonin and Tamoxifen
Exposure to light at night, which shuts off nighttime production of the hormone melatonin, renders breast cancer resistant to tamoxifen, a widely used breast cancer drug. Researchers report that melatonin by itself delayed the formation of tumors and significantly slowed their growth. They also found that tamoxifen was enhanced by sleep and supplementation. Nighttime levels of melatonin are boosted by complete darkness. Animal subjects receiving melatonin supplementation, even during dim light at night exposure, experienced a reduction in tumors (Dauchy, 2014).