Type 2 diabetes is becoming increasingly widespread throughout the world. Research has shown that lifestyle habits, such as exercise and nutrition, play a crucial role in the development of the disease. In some studies, high-cholesterol diets have been associated with disturbances in glucose metabolism and risk of type 2 diabetes. In contrast, in some experimental studies, the consumption of eggs has led to improved glucose balance, among other things. However, there is no experimental data available on the effects of egg consumption on the incidence of type 2 diabetes. In population-based studies, too, the association between egg consumption and type 2 diabetes has been investigated only scarcely, and the findings have been inconclusive. Egg consumption has either been associated with an elevated risk, or no association has been found.

The dietary habits of 2,332 men aged between 42 and 60 years were assessed at the baseline of the Kuopio Ischaemic Heart Disease Risk Factor Study, KIHD, at the University of Eastern Finland in 1984-1989. During a follow-up of 19.3 years, 432 men were diagnosed with type 2 diabetes.

The study found that egg consumption was associated with a lower risk of type 2 diabetes as well as with lower blood glucose levels. Men who ate approximately four eggs per week had a 37 per cent lower risk of type 2 diabetes than men who only ate approximately one egg per week. This association persisted even after possible confounding factors such as physical activity, body mass index, smoking and consumption of fruits and vegetables were taken into consideration. The consumption of more than four eggs did not bring any significant additional benefits.