Contrary to an earlier study, University of Florida researchers reported Wednesday that infants who drink cow's milk are not more susceptible to developing insulin-dependent diabetes later in life.
The study of 210 patients questions an earlier scientific report suggesting that a protein in cow's milk could set off the destruction of the insulin-producing cells and lead to diabetes, the researchers said in the New England Journal of Medicine."We found no evidence that individuals with insulin-dependent diabetes or those with a family history of the disease produced antibodies against this milk protein significantly more often than individuals in our control group or those with other autoimmune diseases," said Dr. Mark Atkinson, an assistant professor of pathology.
The milk protein known as BSA, bovine serum albumin, was identified by researchers at the Hospital for Sick Children in Toronto in July 1992 as a likely trigger for insulin-dependent diabetes, also known as Type I or juvenile diabetes.
The researchers suggested that in people genetically prone to the disease, the immune system confuses the milk protein with a similar protein found on the surface of insulin-producing cells and that the immunity generated by the body to attack the milk protein also attacks the insulin-producing cells.
The Florida researchers did not find evidence to back the Toronto findings.
"We found that 10 percent of patients with insulin-dependent diabetes produced antibodies to the milk protein, while patients with various other autoimmune diseases not involving insulin-producing cells had the antibodies 14-31 percent of the time," said Atkinson.
"We found that 19 to 24 percent of close relatives of insulin dependent diabetics and 3 percent of our control group produced these antibodies."
The researchers said that while those individuals with autoimmune diseases - including diabetes - have slightly more antibodies to the milk protein, the amounts are not sufficient for the milk protein to be considered the trigger for the disease.
Experts caution it is still too soon to make final conclusions.
"These research findings by Dr. Atkinson's group are clearly important," said Dr. Joan Harmon, chief of the diabetes research section at the National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Md.
"These results suggest the earlier concerns regarding cow's milk as an environmental trigger require further investigation," she said.