There are two main forms of diabetes. Type 2 diabetes is thought to result from poor quality diet and too little exercise. In particular, the Western diet and Western lifestyle is thought to contribute significantly to the development of type 2 diabetes. Poor diet and a lack of exercise causes a reduction in insulin sensitivity that over time worsens and leads to insulin resistance. Insulin resistance in turn leads to excessive insulin secretion and increases in fasting insulin levels, which results in blood sugar aberrations. Over time the stress of this dysfunction damages the pancreas and can result in insufficient insulin production and release. Type 1 diabetes is different to type 2 diabetes, because it is thought that the pancreas is damaged not by overworking, but through an autoimmune reaction that destroys the insulin producing beta cells. However, there is strong evidence that this effect might also be nutritionally linked. Certain proteins in the diet and a lack of vitamin D are thought to be involved.
What triggers the autoimmune response in type 1 diabetes has been investigated. Two culprits that have been identified include proteins in cow’s milk (bovine serum albumin and bovine insulin) as well as the wheat protein gluten. Antigens on these proteins might be recognised as foreign, and their similarity to antigens on the surface of beta cells in the pancreas may initiate destruction of the beta cells by the immune system. Evidence suggests that those not exposed to cow’s milk in early years because they are breast fed may have a reduced risk of developing type 1 diabetes. Poor vitamin D status has been shown to be associated with an increased risk of developing type 1 diabetes, and this might relate to the function of vitamin D at modulating immune response. That breast milk is a good source of the biologically active form of vitamin D, 25-hydroxyvitamin D, and is also able to support proper gut development and immunity, suggests that early reliance of cow’s milk may play a role in the development of type 1 diabetes.