If you’re a breast cancer patient, chances are you’ve heard every reason in the book for why you should try to make sure you’re getting enough sleep. You’ve probably also heard a billion or so tips for getting to sleep or staying asleep, some of which work and some of which don’t. But we bet you haven’t heard that sleeping too much could actually be harming your body instead of helping it heal.
A 2017 study of 3682 women who had been diagnosed with breast cancer found that women who reported sleeping longer than the recommended amount per night were more likely to die than those who slept less. Women who regularly slept more than nine hours in a 24-hour period after their diagnosis had about a 34 percent higher chance of death from all causes and a 46 percent higher chance of cancer-related death than those who did not sleep more than nine hours per night.
An increase in the amount of time spent sleeping per night after diagnosis as compared to pre-diagnosis—even if the increased amount was still less than nine hours per night—was also associated with an increased mortality risk.
Kristen Knutson, a researcher at the Center for Circadian and Sleep Medicine at Northwestern University’s Feinberg School of Medicine in Chicago (but who was not involved in the study), had this to say about sleep:
“Sleep should be considered a vital sign. Changes in sleep and excessive sleepiness are important signs that physicians can use to help care for their patients.”
It’s important to note, however, that this study shows only a correlation between excess sleep and mortality rates; it does not prove that too much sleep causes people to be more likely to die of breast cancer. Part of the reason for the correlation could be that those who are losing their battles with cancer may experience greater levels of fatigue than those who are on the path to being cancer-free, causing them to sleep more. In this scenario, sleep is the result rather than the cause.
Those who reported higher amounts of sleep were also more likely to be obese and have more advanced cancers, which could be factors in the higher death rate.
More research will need to be done on the subject to learn the real relationship between sleep and health in breast cancer patients. But for now, remember to trust your body and do your best to follow your doctor’s orders. It’s a wise idea to get the recommended amount of sleep for your age demographic, but try not to go too far above the recommended amount.
Elizabeth Nelson is a wordsmith, an alumna of Aquinas College in Grand Rapids, a four-leaf-clover finder, and a grammar connoisseur. She has lived in west Michigan since age four but loves to travel to new (and old) places. In her free time, she. . . wait, what’s free time?