The Link Between Sleep and Breast Cancer
What time you hit the pillow and how restful your shut-eye is can affect your breast cancer risk, new research shows. Here’s how to sleep better and protect your health.
You probably know sleep is important for mood, appetitite, and crushing your workouts—but bad sleep hygiene can have more serious consequences. What time you hit the pillow and how restful your shut-eye is can affect your breast cancer risk, new research shows. Disruptions of your circadian rhythm, which can result from poor sleep, may play a role in breast cancer.
“Factors like light or noise can suppress melatonin at night, when levels are supposed to be high. The body responds by releasing estrogen from the ovaries at times of day it normally wouldn’t,” says Carla Finkielstein, Ph.D., an associate professor at the Virginia Tech Carilion School of Medicine. In some cases, the constant, unscheduled release of hormones like this could increase cancer risk.
Occasional bad nights are nothing to worry about, but anything that throws off your z’s chronically is. These three tips will help you get the nightly rest you need.
Shut down disruptions.
Waking up more than twice a night is associated with a 21 percent increase in the risk of breast cancer, new research in the European Journal of Cancer Prevention shows. Fragmented sleep changes the white blood cells in a way that promotes tumor growth, according to an earlier study in mice, says Dorraya El-Ashry, Ph.D., the chief scientific officer of the Breast Cancer Research Foundation.
Take steps to make your sleep more peaceful. If you live on a noisy street, for instance, consider getting a pink noise machine. (Pink noise is similar to white noise but has been proved to boost sleep quality.) If you often wake up with a sore throat or neck pain, you may snore; 88 percent of women do, but only 72 percent know it. Changing your sleeping position, getting a new pillow, or wearing a mouth guard can help; ask your doctor or dentist for advice. (Related: Study Finds That 'Beauty Sleep' Is Actually a Real Thing)
Stick to this two-hour window.
Studies have indicated that a rotating night shift, in which you work three or more nights a month in addition to day shifts, can increase your risk of cancer over time because your body clock can never fully adjust. “These chronic circadian disruptions have serious implications for cancer as well as obesity, heart disease, and inflammation,” Finkielstein says. Aim to wake up and fall asleep within the same two-hour window every day to minimize the effects. (Related: What's Worse: Sleep Deprivation or Disrupted Sleep?)
Use mood lighting.
One of the top things that suppresses nighttime melatonin levels is too much light. “Animal studies indicate that irregular circadian cycles caused by continuous exposure to irregular light-dark cycles favor the progression of malignant diseases, like cancer in breast tissues,” Finkielstein says. Cut back on the amount of brightness you’re exposed to at least an hour or two before bedtime, El-Ashry says. Ideally, try for a candlelight level of ambient light—meaning just enough to see where you’re going. Turn off your electronics earlier too. (See: The Best Light-Blocking Sleep Masks, According to Amazon Reviews)
Shape Magazine, October 2019 issue