Nutrition, Immunity, and Autoimmune Diseases

Abstract

Autoimmunity happens when the immune system recognizes autoantigens as foreign harmful agents. It is a multifactorial condition predominantly resulting from autoreactive B cells and T cells. Inflammatory processes and excessive cytokine production are mainly involved in the pathogenesis of autoimmune disease. Many factors including environmental and genetic factors play role in autoimmune diseases. There is a myriad of elements related to autoimmunity including cross-reactivity with autoantigens, defect in tolerance, and lymphoproliferative dysregulation. There are two types of autoimmune diseases. Tissue-specific and systemic autoimmune disorders happen through the host immune reaction against a specific antigen in a particular tissue and/or multiple organs and tissues, respectively. In tissue-specific autoimmune diseases, both T cells and B cells are engaged in recognition of self-antigens. Autoimmune thyroiditis, type 1 diabetes, multiple sclerosis, inflammatory bowel disease, and autoimmune liver diseases are examples of this type of autoimmunity. Systemic autoimmune diseases are characterized by the production of autoreactive antibodies against different autoantigens including nuclear components, cell surface molecules, and intracellular matrix proteins. Systemic lupus erythematosus, Sjögren’s syndrome, and rheumatoid arthritis are examples of systemic autoimmune disorders. Recent research found that nutrition and dietary factors are important for the development of autoimmunity. A healthy diet can help the immune system to better control discrimination of self from nonself. However, the exact effects of nutrients on the initiation of an autoimmune condition are not clear. Although there is no specific diet for the treatment of autoimmune diseases, there are nutrients known to influence functioning of the immune system. Some can affect T-cell proliferation and Th1 activation that are involved in the development of autoimmunity. An anti-inflammatory diet limited in pro-inflammatory compounds can be used to control autoimmunity. Nutrients can prevent inflammation through restriction of the production of pro-inflammatory cytokines including IFN-γ and through promotion of regulatory T-cell function.