Lower consumption of cow milk protein A1 β-casein at 2 years of age, rather than consumption among 11- to 14-year-old adolescents, may explain the lower incidence of type I diabetes in Iceland than in Scandinavia

Aim: To compare the consumption of the cow milk proteins All and B P-casein among children and adolescents in Iceland and Scandinavia (Norway, Denmark, Sweden and Finland) as this might explain the lower incidence of type 1 diabetes (per 100,000/year, 0-14 years) in Iceland. Methods:The consumption of All beta-casein in each country among 2- and 11- to 14-year-old children was calculated from results on food intake and on cow milk protein concentration. The consumption values were then compared and evaluated against the incidence of type 1 diabetes. Results: There was a significant difference between the consumption of A1 (p = 0.034) as well as the sum of A1 and B (p = 0.021) beta-casein in Iceland and Scandinavia for 2-year-old children. In the same age group, consumption of All P-casein correlated with the incidence of type 1 diabetes in the countries (r = 0.9; p = 0.037). No significant difference in consumption of All or the sum of All and B beta-casein was found for 11 - to 14- year-old adolescents. Conclusion: This study supports that lower consumption of A1 beta-casein might be related to the lower incidence of type 1 diabetes in Iceland than in Scandinavia. Additionally it indicates that consumption in young childhood might be of more importance for the development of the disease incidence than consumption in adolescence.