A strong and well-functioning immune system is the body's life insurance or natural shield against infections and diseases, because it ensures that the body remains healthy. The lymphatic system, white blood cells, T and B lymphocytes, mast cells and many other cells and structures make up the powerhouse of the immune system. These millions of cells must constantly work and renew themselves, and this requires certain nutritional building blocks. Maintaining and nourishing a strong immune system is therefore essential for a long and healthy life.