Dietary factors and the risk of developing insulin dependent diabetes in childhood

Objective--To study different nutrients and food additives as risk factors for insulin dependent diabetes mellitus in childhood. Design--Prospective case-control study. Parents of the children being studied were asked to fill in a questionnaire regarding the children's frequency of consumption of various foods. Parents of children with diabetes were asked about the period before onset of the disease. Setting--Population based study throughout Sweden. Subjects--339 Children aged 0-14 who had recently developed insulin dependent diabetes mellitus and 528 control children matched for age, sex, and county of residence who were traced through the official Swedish population register. Main outcome measures--Foods were classified according to their content of protein, fat, carbohydrates, monosaccharides or disaccharides, nitrosamines, nitrates or nitrites, vitamin C, and fibres. The frequency of intake was categorised as high, medium, and low and the relative risk for developing insulin dependent diabetes was estimated for the three frequencies of intake and calculated as odds ratios. Results--Significant linear trends for dose response in odds ratio by frequency of intake were shown for solid foods containing high amounts of protein (odds ratio for low frequency of intake 1.0; medium 2.3; and high 5.5), and nitrosamines (1.0; 1.7; 2.6) and significant but non-linear trends were found for carbohydrates (1.0; 1.3; 4.4) and nitrates or nitrites (1.0; 0.8; 2.4). The significant trends were not affected when the results were standardised for possible confounders. No significant increases in odds ratios were found for protein, monosaccharides and disaccharides, vitamin C, and fibres. Conclusion--Nutrients and food additives such as protein, carbohydrate, and nitrosamine compounds may influence the risk of developing insulin dependent diabetes in childhood and significant trends in odds ratios indicate a causal relation.