Avoiding Cow's Milk Doesn't Cut Type 1 Diabetes Risk

Miriam E Tucker

January 02, 2018

Avoidance of cow's milk in infants at high risk for type 1 diabetes doesn't prevent development of the condition during childhood, new research indicates.

Long-term results of the randomized multinational Trial to Reduce Insulin-Dependent Diabetes Mellitus in the Genetically at Risk (TRIGR) study were published in the January 2 issue of the Journal of the American Medical Association by Mikael Knip, MD, PhD, of the University of Helsinki, Finland, and colleagues.

Between May 2002 and January 2007, the TRIGR study prospectively enrolled 2159 newborns with human leukocyte antigen (HLA)-conferred type 1 diabetes susceptibility and at least one first-degree family member with the condition. The infants were randomized to be weaned to either a hydrolyzed casein formula without intact proteins or a conventional formula containing 80% intact cow's milk protein.

Dr Knip and colleagues had previously reported from TRIGR that the hydrolyzed formula did not decrease the cumulative incidence of diabetes-associated antibodies among the children by 7 years of age. Now, after a median of 11.5 years, there is no significant difference between the two groups in the proportions who developed type 1 diabetes (8.4% with casein hydrolysate vs 7.6% with cow's milk formula; P = .47).

"These findings do not support a need to revise the current dietary recommendations for infants at increased risk for type 1 diabetes," the authors state.

"Cow's Milk Doesn't Play a Critical Role in Development of Type 1 Diabetes"

Results remained nonsignificant after adjustment for HLA risk group, duration of breastfeeding or study formula consumption, sex, and region, with a hazard ratio (HR) of 1.1 (P = .46). (Study mothers had been encouraged to breastfeed, and rates were high in both groups.)

Analysis of the 1177 infants who had not consumed any other bovine products and who had consumed the assigned formula for at least 60 days also showed no difference in the proportions who developed type 1 diabetes (HR, 1.1; P = .63). There were also no differences by median age at diagnosis, diagnosis without clinical symptoms, diabetic ketoacidosis at presentation, relationship to the affected family member, geographic region, or sex.   

While these findings support the preliminary 2014 TRIGR data, they contrast with a pilot study published in 2010 in the New England Journal of Medicine, which had found a reduction in type 1 diabetes-associated autoantibodies among children at age 7.5 years who had received hydrolyzed vs conventional formula in infancy.

That study, the authors point out, included just 230 at-risk Finnish children, while TRIGR enrolled 2159 high-risk children from 15 countries including Canada, Finland, and the United States. 

"The larger number of participants in this study provides substantially greater statistical power in a more heterogeneous study population compared with the pilot study and, therefore, provides a more definitive answer to whether weaning to an extensively hydrolyzed formula is protective of diabetes," they say.

"This trial suggests that cow's milk does not play a critical role in the development of type 1 diabetes."

The TRIGR study was supported by the Eunice Kennedy Shriver National Institute of Child Health and Development and National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Canadian Institutes of Health Research, JDRF, and Commission of the European Communities. Other funding was provided by the European Foundation for the Study of Diabetes/JDRF/Novo Nordisk Focused Research Grant, Academy of Finland, Dutch Diabetes Research Foundation, and Finnish Diabetes Research Foundation. Mead Johnson Nutrition provided the blinded color-coded study formulas. Dr Knip reported receiving grants from the NIH.

JAMA 2018;319:38-48. Abstract

For more diabetes and endocrinology news, follow us on Twitter and on Facebook.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.