The Link Between the Immune System & Weight

Interleukin-6 (IL-6) is a chemical messenger in our immune system that plays an important role in fighting off infection. It is known that our normally low levels of interleukin-6 in the brain increase dramatically during an infection, typically accompanied by reduced hunger and fatigue. Erik Schele, from the University of Gothenburg (Sweden), and colleagues have identified specific types of brain cells that the IL-6 molecule targets, and have observed that lab animals whose brains produce abundant quantities of the molecule exhibit less hunger and more satiety. The study authors submit that: “Our data demonstrate that the MCH neurones of the human hypothalamus, as well as the [melanin-concentrating hormone] and orexin neurons of the mouse hypothalamus, contain [interleukin-6 receptor alpha]. This opens up the possibility that [interleukin-6] influences the energy balance.”