Cow's Milk Formula May Increase Type 1 Diabetes Risk
More Evidence to Support Breastfeeding At-Risk Infants
By Denise Mann
WebMD Medical News
Reviewed by Aman Shah, MD
July 23, 2001 -- Debate continues about whether feeding cow's milk to an infant increases the risk of developing type 1 diabetes -- but new evidence supports that it in fact does. In a study of newborns at high risk for type 1 diabetes, those fed infant formula made with cow's milk had a higher risk of developing the disease compared with those fed formula containing casein hydrolysates. The findings were reported recently at the annual meeting of the American Diabetes Association in Philadelphia.
"The studies [to date] are a mixed bag," says Alan Greene, MD, assistant clinical professor of pediatrics at Stanford University School of Medicine in Palo Alto, Calif. "Clearly the answer is not in, but if there is someone with type 1 in the immediate family, I recommend breastfeeding for as long as possible -- at least 1 year -- or to avoid cow's milk formula for the first 6 to 8 months."
After exclusive breastfeeding, 208 babies who carried alleles putting them at high risk of developing type 1 diabetes were randomized to receive formula made with or without cow's milk until they were 6-8 months of age. During the 3-year observation period, the researchers documented a 39-57% decrease in auto-antibodies and antibodies to islet cells suggestive of type 1 diabetes in infants on casein hydrolysate compared with infants on the cow's milk-based formula.
Overall, those fed formula made without cow's milk were about 50% less likely to develop type 1 diabetes. Thus the researchers postulate that it may be possible to change autoimmunity patterns through dietary interventions.
Another study has shown that drinking about three glasses of cow's milk per day increased the risk type 1 diabetes among children with siblings who have the disease, suggesting that some proteins in cow's milk may induce the immune system to attack insulin-producing cells.
Other studies have, however, have found that infants fed cow's milk are no more likely to develop the disease than infants who are breastfed. Experts say that a new 17-country trial of about 3,000 children may provide a definitive answer.
"The studies are split," says John Buse, MD, the director of the Diabetes Care Center at the University of North Carolina at Chapel Hill. "I think breastfeeding is good, and it may also be good for reducing diabetes risk."
"The most recent literature supports that breastfeeding can prevent type 1 diabetes," agrees Davida Kruger, RN, diabetes educator and nurse practitioner at Henry Ford Hospital in Detroit.