Intermittent Fasting Affects Immunity
Research in Nature Reviews Immunology found that intermittent fasting can expel long-lived plasma cells from their survival niche, potentially altering the body's long-term immune response. While clinical implications are still unclear, this adds complexity to the relationship between dietary habits and immune function.
Long-lived plasma cells (LLPCs) are the immune system's memory keepers, responsible for maintaining durable humoral immunity. These cells can survive for years, often a lifetime, residing in specialized niches within the bone marrow where they continuously produce antibodies against past infections or vaccinations. The survival of these plasma cells is not intrinsic but dependent on continuous signals from their microenvironment, or "niche." This niche provides the necessary factors for their longevity, and disrupting it can affect their ability to survive and produce antibodies. Broader research has shown that cycles of fasting and refeeding can trigger a regenerative process in the immune system. Studies from the University of Southern California found that prolonged fasting helps clear out old and damaged immune cells, and the subsequent re-feeding phase prompts hematopoietic stem cells to create new ones. Beyond cellular regeneration, intermittent fasting has been linked to a reduction in systemic inflammation. Clinical trials have observed lower levels of inflammatory markers like C-reactive protein (CRP) and interleukin-6 (IL-6) in individuals practicing various forms of fasting. However, the effects can be complex and are not universally positive. A 2020 study on mice with a lupus-like autoimmune disease found that intermittent fasting actually worsened their condition by increasing the number of autoantibody-secreting plasma cells. The potential to modulate LLPCs is of high interest for autoimmune diseases, which are often driven by autoantibodies. Yet, these autoreactive plasma cells are known to be highly resilient, in some cases even surviving targeted therapies designed to deplete immune cells.
