RheumaShield from Douglas Laboratories contains 10 mg of native, undenatured type II collagen (UC II)from chicken sternum cartilage.UCII? is a patented form of undenatured type II collagen. Collagen is a fibrous protein secreted by connective tissue and is the prime structural component of skin, bones and joints. It represents close to 25% of all the bodys protein. Although about 15 types of collagen have been found in various parts of the body, the fibrillar type II collagen is distributed primarily in articular cartilage, i.e. cartilage associated with joints. UCII? is from cartilage that has been sterilized without substantially altering its chemical or molecular structure. This type of collage preparation has been shown to maintain the healthy structure and function of articular joints that are damaged by inflammatory conditions such as rheumatoid arthritis, an autoimmune disease.Rheumatoid arthritis occurs when ones own immune system, primarily T cells, attacks itself, i.e. the type II and IX collagen as well as proteoglycans in its articular joint cartilage. The result of this autoimmune attack is painful and disabling inflammation and destruction of the structure and function of cartilage in articular joints. Rheumatoid arthritis is associated with substantial morbidity and premature mortality from comorbid diseases.Studies have shown that oral administration of native, i.e. undenatured, type II collagen significantly improves rheumatoid arthritis, by a mechanism known as oral tolerance. Oral tolerance is a state of anergy or hyporesponsiveness that follows the exogenous administration of antigen to the peripheral immune system via the gut. Animal studies of experimental autoimmune diseases such as collagen-induced arthritis, insulin-dependent diabetes, and experimental autoimmune encephalomyelitis have demonstrated the effectiveness of oral tolerance.The size of the antigen dose determines the mechanism of oral tolerance. In response to a low oral dose of an