If you’re sleep deprived, you not only weaken your immune system, but you also deprive yourself of the time when body naturally does some of its best work to heal and repair itself. We’ve known for a while of the relationship between sleep and immune function. Both sleep and immune system activity are both regulated by circadian rhythms. Lunaire Keto And sleep—especially slow-wave sleep—is a time when the body’s immune activity goes into high gear, releasing more of its fighter cells, repairing damaged cells, and pushing back against disease. From the common cold to cancer, we’ve seen scientific evidence supporting sleep’s role in fighting illness.