The Immune System Also Helps a Healthy Body
Immune support
New research shows the immune system is also busy when one is perfectly healthy. For instance, it helps the body convert fat into energy during fasting, according to researchers from the University of Southern Denmark. The immune system continues to work hard even when not challenged by an incoming pathogen or virus. This is shown in a new study published in the scientific journal Cell Metabolism.
Until recently, it was believed that the immune system was mostly dormant unless the body was under attack in connection with infections. However, it now turns out that the immune system most likely also plays an important role for perfectly healthy people and can affect the body’s production of vital energy sources, says study co-author, Anne Loft, from the university’s Department of Biochemistry and Molecular Biology.
Specifically, the immune system causes the liver of the healthy body to produce an energy source called ketone bodies. This takes place by letting the liver burn fat during fasting. “When we’re fasting—that is, we haven’t eaten anything for maybe half a day or a full day—we start drawing on our fat deposits, but not all of our body cells are capable of burning fat. This applies, among other things, to the brain, which instead depends on the production of ketone bodies, which the liver forms by metabolizing fats. The ketone bodies thereby energize the body, allowing us to function even if we don’t eat anything, explained co-author Søren Fisker Schmidt, assistant professor at the university’s Department of Biochemistry and Molecular Biology.
Ketone bodies are also the focal point of many popular weight loss diets focusing on cutting carbohydrates from our food, so the body begins burning fat instead. Other research also suggests that the ketone bodies may have a positive impact on, among other things, risk factors for the development of cardiovascular disease.
“We now believe that the immune system affects the production of ketone bodies in fit and healthy individuals and given the beneficial effects of ketone bodies in various common metabolic disorders, this knowledge can hopefully also be applied to understand how the immune system is trying to keep the body in equilibrium when we’re sick,” Loft explained.
Loft A, et al. “A macrophage-hepatocyte glucocorticoid receptor axis coordinates fasting ketogenesis.” Cell Metabolism, 2022.
