In Why We Sleep, Dr. Mathew Walker tells us:
“Natural killer cells are an elite and powerful squadron within the ranks of your immune system. Think of natural killer cells like the secret service agents of your body, whose job it is to identify dangerous foreign elements and eliminate them—007 types, if you will. One such foreign entity that natural killer cells will target are malignant (cancerous) tumor cells. Natural killer cells will effectively punch a hole in the outer surface of these cancerous cells and inject a protein that can destroy the malignancy. What you want, therefore, is a virile set of these James Bond–like immune cells at all times. That is precisely what you don’t have when sleeping too little. PhD Michael Irwin at the University of California, Los Angeles, has performed landmark studies revealing just how quickly and comprehensively a brief dose of short sleep can affect your cancer-fighting immune cells. Examining healthy young men in a careful study that controlled for spurious factors, such as physical activity, Irwin demonstrated that a single night of four hours of sleep—such as going to bed at three a.m. and waking up at seven a.m.—swept away 70 percent of the natural killer cells circulating in the immune system, relative to a full eight-hour night of sleep. That is a significant state of immune deficiency to find yourself facing, and it happens quickly, after essentially one ‘bad night’ of sleep…
Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer.“
It turns out that sleeping can help prevent cancer. When we get adequate sleep, we have significantly more 007 natural killer cells floating around our immune system, searching for and destroying cancerous cells.
