Benefits of the procedure wear off in most diabetes patients within three to five years, largely because the donor islets can become damaged during transplantation.

WSJ: Cow's Milk Blamed for Too Many Infant Allergies

The procedure, known as pancreatic islet transplantation, involves injections of healthy islets, or cell clusters, that release insulin.

WSJ: Cow's Milk Blamed for Too Many Infant Allergies