Immune System Reboots During a Good Night’s Rest

T-cells are a type of lymphocyte (a subtype of white blood cell) that play a central role in cell-mediated immunity. In this study, researchers took blood samples from fourteen healthy men and found the levels of all types of T-cells fell when they had a full night’s sleep. However, their T-cell levels stayed high when they stayed awake all night. Study author Dr. Luciana Besedovsky notes the rapid fall in T-cell levels during sleep shows “that even one night without sleep affects the adaptive immune system… This might be one reason why regular sleep is so important for general health.” American Journal of Physiology, January 2017