Poor Sleep Speeds Up Cancer Growth
Do you want another reason why should strive for a good night’s sleep? A recent study published in Cancer Research showed that poor sleep in laboratory mice led to faster cancer growth. We’ve written previously about the importance of getting good restful sleep and this study appears to provide another healthy reason for the importance of sleep.
The study involved injecting mice with tumor cells into their muscles. Sleep was interrupted in the half the mice by moving a quiet motorized brush through the cages every 2 hours waking up the affected mice (I’m not sure why the motor needed to be quiet if the goal was to wake up the mice – kind of like using sterile technique during execution with a lethal injection – does it make a difference?). After 4 months the researchers noted that the sleep-interrupted mice had tumors twice the size as the mice who were allowed to sleep uninterrupted.
David Gozal, the study’s director from the University of Chicago said, “It’s not the tumor. It’s the immune system. Fragmented sleep changes how the immune system deals with cancer in ways the make the disease more aggressive.” This study is believed to be the first (which is why we are reporting it) to show in an animal model that fragmented sleep affects tumor growth and aggressiveness. There is known to be an associated between sleep apnea and cancer mortality in humans.
Usually muscle tumors are contained or encapsulated separtating the tumor cells from normal, healthy tissues. However, in the sleep disrupted mice tumors were able to grow through the capsule allowing them to more or less grow unabated. In the sleep interrupted mice TAM cells (tumor-associated macrophages) were stimulated to produce more blood vessels allowing the tumors to grow. But, in the mice who were allowed to sleep uninterrupted the TAM cells worked in the center of the tumor and eliminated cancer cells. So poor sleep changes how the immune system works.
The researchers are conducting other studies looking at the link between poor sleep and cancer.
BOTTOM LINE: Do not underestimate the importance of getting uninterrupted restful sleep.