How Does Sleep Influence Cancer Risk?
Getting enough sleep is important for overall health and may be related to cancer risk.
IS THERE ANY BETTER feeling than waking up refreshed and rested after a really good night’s sleep? That sensation might be an indication of how good high-quality sleep is for you, not just for meeting the challenge of the day ahead, but for your longer-term health and wellness. A growing body of research into the connection between sleep and chronic diseases has noted that there could be an association between shut-eye and your chances of being diagnosed with an illness such as diabetes or cancer later on.
It seems intuitive that there might be a connection between sleep and cancer risk. After all, cancer is an overgrowth of cells that should otherwise have been regulated or repaired before they got out of control. Much of the body’s work to regulate this cellular growth occurs during sleep. “So many things are happening while we’re asleep,” says Amanda Phipps, an epidemiologist and researcher at Fred Hutchinson Cancer Researcher Center in Seattle. “It’s a time when we most efficiently repair DNA damage. The body is also doing things like controlling the growth of cells, turning on certain genes and switching off others and promoting the immune system. Sleep is a time for repair and restoration of our bodies, but it’s more than just that. It’s also building up our immune systems so we can better protect ourselves during the day.”
If that period of time when the body is busy rebooting and fortifying its defenses is chronically shortened or disrupted, it stands to reason that could eventually have serious repercussions for cancer risk down the road.
“From a biological perspective, there are a lot of good reasons for us to suspect that insufficient sleep, chronic sleep debt or short sleep duration could have an impact on the development of cancer,” Phipps says. “We know in particular that when people don’t get enough sleep, when they’re chronically sleep-deprived, we see that can lead to chronic inflammation and insulin resistance.” Chronic inflammation has been associated with several kinds of cancer, and insulin resistance is a precursor to diabetes that occurs when your cells don’t respond appropriately to the insulin the pancreas makes to help your cells take up glucose from your blood. Inflammation and insulin resistance can both “set the stage for cancer by contributing to DNA damage,” Phipps says.
In addition, “inadequate sleep also results in suppressed levels of melatonin,” a hormone that promotes sleep but also “can play a role in protecting against DNA damage and acts as a tumor suppressor. When we’re not getting enough sleep, all these things can happen, which in theory could really set the stage for promoting the development of cancer,” she says.