As an integrated system of cells, tissues, and organs, the immune system protects the body against infection and disease.
Specifically, the immune system fights against bacteria, viruses and fungi. It must recognize foreign invaders and abnormal cells to generate the immune response, sometimes in the form of inflammation. For this reason, the immune system can be a double-edged sword, as inflammation can cause damage to tissues while fighting against foreign invaders.
Nutrition and Immunity
Given that nutritional status can affect the actions of the immune system, it is not surprising that immunology and nutrition are tightly connected. Malnutrition is the most common cause of immunodeficiency in the world, and chronic malnutrition one of the leading causes of death. But malnutrition is not the only factor affecting immune function. Poor overall nutrition can lead to micronutrient deficiencies, such as zinc, magnesium and vitamin D, that may compromise immune system function, making nutrition an important aspect of maintaining a healthy immune system. 1, 2
1 Calder, P.C., 2013. Feeding the immune system. Proceedings of the Nutrition Society, 72(3), pp.299-309.
2 Katona, P. and Katona-Apte, J., 2008. The interaction between nutrition and infection. Clinical Infectious Diseases, 46(10), pp.1582-1588.