In families with established type 1 diabetes, all first-degree relatives, including the parents of the proband (if they are < 45 years of age) are at increased risk for type 1 diabetes [because of the genetic link] and should be counseled regarding this risk. Identical twins are the greatest risk. Second- and third-degree relatives of a proband with type 1 diabetes are also at heightened risk if they are < 21 years of age.
In addition to informing families about the opportunities for diabetes prevention trials, it is reasonable to wonder whether primary care providers can make recommendations that may limit future diabetes risk. Although many current trials are developing pharmacological approaches to type 1 diabetes prevention, some trials are investigating approaches that can be utilized routinely and safely in practice.
For example, there has been growing interest in the potential role of early feeding patterns in the development of diabetes. This interest is founded on a body of evidence suggesting a protective effect of breastfeeding for children at risk for type 1 diabetes. In 1984, Borch-Johnson et al. first reported an inverse correlation between the duration of breastfeeding and diabetes risk in humans. Since then, there has been a long debate in the literature about the possible beneficial effects of breastfeeding for children at risk for type 1 diabetes.
Part of the challenge has been isolating the effects of breastfeeding from other potentially contributing factors (e.g., delayed exposure to exogenous stimuli such as cow’s milk proteins). Nevertheless, both prolonged breastfeeding and delayed exposure to cow’s milk proteins have been associated with protection against the development of type 1 diabetes. Putative mechanisms of protection include passive immunity provided by secreted immunoglobulin A antibodies against infectious agents that may contribute to the autoimmunity trigger and delayed exposure to diabetogenic agents such as cow’s milk proteins, which may be involved in the pathogenesis of type 1 diabetes among those with a dysfunctional gut immune system.
The Trial to Reduce IDDM in the Genetically at Risk (TRIGR) is the first primary prevention effort to explore whether avoidance of exposure to cow’s milk can prevent type 1 diabetes in infants with a genetic predisposition. Although this ongoing trial is limited to genetically high-risk infants, it is reasonable to recommend breastfeeding to families in which there is risk for type 1 diabetes. Current recommendations include exclusive breastfeeding for the first 6 months of life for those without contraindications. Whether specific alternate formulas would be of benefit is the subject of ongoing trials. As their tolerability is low and expense high, we would not recommend these at the present time.
Another protective intervention of ongoing interest is early vitamin D supplementation. The exact mechanism by which vitamin D may protect against type 1 diabetes remains unclear, but this effect is likely to be through the prevention of vitamin D deficiency. Vitamin D is a potent modulator of the immune system and is involved in regulating cell proliferation and differentiation. A meta-analysis of data from five observational studies recently indicated that children supplemented with vitamin D had a 29% reduction in type 1 diabetes risk compared to their unsupplemented peers. Nevertheless, firm conclusions that can be drawn from these data in terms of appropriate recommendations are limited by the lack of specification of dosage, duration, and particular vitamin D preparations. Thus, data from adequately powered, randomized, controlled trials are still needed.
Although current trials are generally considering pharmacological dosing of vitamin D, it is reasonable to ensure that individuals at risk for autoimmune disease maintain their vitamin D stores in the normal range if they are not able to participate directly in these trials. It is currently recommended that all infants should receive 400 IU of vitamin D supplementation until the infant is ingesting at least 400 IU of vitamin D daily through formula, milk, or other food sources. In addition, it is recommended that an intake of 400 IU of vitamin D per day be continued throughout childhood and adolescence for those who do not ingest that amount per day or for those who do not receive adequate sunlight exposure.
Health-e-Solutions comment: Excellent article discussing a couple of practical things parents with at-risk children can do to help prevent the development of type 1 diabetes. Breastfeeding and the avoidance of cow’s milk (we believe cow’s milk and all dairy should be permanently avoided) are important. Vitamin D is important. We think vitamin D supplementation should be used to get the body into the high normal range. Consult your medical professional to see if this supplementation is right for you.
Not mentioned in this article is the protective effect of omega-3 oils. This should also be a daily supplement for families at risk. We believe the diabetic-alkaline lifestyle seeks to maximize all of these and more. With a diet rich in healthy foods and keeping high-glycemic foods out, we believe we put our bodies in a position of strength to function optimally.