A new study suggests that cancer survivors often suffer from chronic fatigue, and when they do, waking up to bright white light may help them sleep better.
According to Reuters, for the month-long study, researchers had 44 cancer survivors sit very close to a light box early every morning for 30 minutes.
The patients were randomly assigned to therapy with either bright white light or dim red light. More than half of the participants suffered from what’s known as poor sleep efficiency, a measure of how much time in bed people spend asleep.
After a month of treatment, 86 percent of the people exposed to bright white light had normal sleep efficiency, while 79 percent of the people exposed to dim bright light still had poor sleep efficiency.
The study leader Lisa Wu of the Northwestern University Feinberg School of Medicine in Chicago and the Icahn School of Medicine in New York City said it’s possible that the bright white light helps cancer survivors reset their internal clocks, or circadian rhythms, so that their body can more easily rest at night and wake during the day.
Wu explained by email: “Cancer survivors and even other individuals who spend most of their days indoors may not receive enough bright light to keep their biological rhythms synchronized. Given that light exposure from being outside is generally much brighter than light received indoors, the addition of artificial bright light each morning helps cancer survivors reduce fatigue and improve their sleep quality by strengthening their circadian rhythms.”
This suggests that ongoing therapy may be needed for cancer survivors to experience a sustained improvement in sleep.
Ilia Karatsoreos of the Sleep and Performance Research Center at Washington State University in Pullman, who wasn’t involved in the study said that this research is different because it includes people with different types of cancer, including blood malignancies, breast tumors and gynecological cancers.