Diabetes is caused by environmental Factor.

The onset of type 1 diabetes is often associated with or follows certain infections. Common infections include Mumps virus virus, rubella virus, Cytomegalovirus virus, measles virus, influenza virus, encephalitis virus, poliovirus, coxsackie virus and Epstein-Barr virus, the susceptibility or resistance to diabetes may be determined by nature. If two people (such as siblings) are exposed to the same viral infection, they may show the same increase in antibodies to the virus, whereas diabetes may occur in only one person, this may be due to differences in inherent genetic predispositions. Susceptibility may mean that B cells are sensitive to a specific dose of a virus, or that they are prone to an autoimmune response to an autoantigen that is expressed and released during b-cell antigen or mild b-cell damage.

Recent studies have reported a higher risk of developing Type 1 diabetes in children who are fed milk or milk formula within 3 months of birth. Studies suggest that certain proteins in milk may be a contributing factor to diabetes, such as bovine serum albumin, which has antibodies against bovine serum proteins that have been detected in most people with type 1 diabetes, the antibody can precipitate with 69000 protein in islet B cell lysate. The antibody production is thought to be due to the fact that intestinal permeability in infants and young children allows the protein to enter the circulation, where bovine serum albumin causes lymphocyte sensitization and the development of a humoral and cellular immune response that crosses with the 69,000 protein of islet B cells, that eventually leads to B-cell destruction. The other two proteins, beta lactoglobulin and casein, are also considered to be independent risk factors for type 1 diabetes. It has also been speculated that feeding infants with high-calorie formula may cause increased insulin secretion and enhanced islet B cell antigen presentation in infancy. However, the relationship between cow’s milk and type 1 diabetes is not clear, and there is still a great debate about cow’s milk protein as the initial factor of type 1 diabetes.