There aren't many known risk factors for type 1 diabetes, though researchers continue to find new possibilities. Some known risk factors include:

  • A family history. Anyone with a parent or sibling with type 1 diabetes has a slightly increased risk of developing the condition.
  • Genetics. The presence of certain genes indicates an increased risk of developing type 1 diabetes. In some cases — usually through a clinical trial — genetic testing can be done to determine if someone who has a family history of type 1 diabetes is at increased risk of developing the condition.
  • Geography. The incidence of type 1 diabetes tends to increase as you travel away from the equator. People living in Finland and Sardinia have the highest incidence of type 1 diabetes — about two to three times higher than rates in the United States and 400 times that of people living in Venezuela.

Possible risk factors for type 1 diabetes include:

  • Viral exposure. Exposure to Epstein-Barr virus, coxsackievirus, mumps virus or cytomegalovirus may trigger the autoimmune destruction of the islet cells, or the virus may directly infect the islet cells.
  • Early vitamin D. Research suggests that vitamin D may be protective against type 1 diabetes. However, early drinking of cow's milk — a common source of vitamin D — has been linked to an increased risk of type 1 diabetes.
  • Other dietary factors. Omega-3 fatty acids may offer some protection against type 1 diabetes. Drinking water that contains nitrates may increase the risk. Consuming dairy products, particularly cow's milk, may increase infants' risk of the disease. Additionally, the timing of the introduction of cereal into a baby's diet may affect risk. One clinical trial found that between ages 3 and 7 months appears to be the optimal time for introducing cereal.

Some other possible risk factors include:

  • Having a mother younger than age 25 when she gave birth to you.
  • Having a mother who had preeclampsia during pregnancy.
  • Being born with jaundice.
  • Having a respiratory infection just after birth.
Jan. 23, 2013

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