Table 1.

The most important environmental factors which possibly contribute to the increased incidence of Type 1 diabetes [1–4]

Environmental factors	Hypothesis
Viral infections (e.g. enteroviruses)	Viral hypothesis
Exposure to certain food constituents (gluten; toxic agents such as nitrite/nitrate)	Dietary hypothesis
Increased hygiene; lack of childhood infections	Hygiene hypothesis
Rapid growth in early childhood	Accelerator hypothesis