Florida Researchers: Formula-Fed Babies Are Not At Greater Risk For Diabetes

May 29, 1996

GAINESVILLE—University of Florida medical researchers have found evidence to refute popular claims that bottle-feeding infants, instead of breastfeeding, is responsible for many cases of childhood diabetes.

In the May 25 issue of the international medical journal The Lancet, Dr. Mark Atkinson and co-research Tamir Ellis debunk the idea that consumption of infant formula containing cow’s milk is associated with an increased risk for insulin-dependent diabetes in genetically predisposed individuals.

“This popular hypothesis indicates that you’re at increased risk not just for diabetes, but for multiple sclerosis, rheumatoid arthritis and other autoimmune (self-attacking) diseases, depending on whether you were breast or bottlefed as an infant,” said Atkinson, pathologist and diabetes researcher at UF’s College of Medicine. “Based on old and new evidence that we have reviewed from a large number of studies, we simply don’t believe that.”

Insulin-dependent diabetes stems from a chronic autoimmune process that slowly destroys insulin-producing cells in the pancreas. Some researchers have reported that formula feeding plays a role in as many as a quarter of the children who contract diabetes.

In 1993, researchers at the Toronto Hospital for Sick Children wrote an article in the New England Journal of Medicine supporting the link. They cited evidence that people with diabetes were more likely to have earlier exposure to cow’s milk and were likely to have been breastfed for a shorter time than those who never developed the disease.

Shortly after many of these findings were made public, the American Academy of Pediatrics, which issues infant formula guidelines, released a report strongly encouraging breastfeeding in children who might otherwise be put at risk for developing autoimmune diseases such as diabetes.

Headlines declared “Drinking infant formula causes diabetes,” and Atkinson’s phone began to ring off the hook.

“The problem with many things in science is that people just don’t conceptualize them because they’re too difficult to understand,” Atkinson said. “But you put out the idea that feeding your child infant formula is bad, and the public can really relate. For that reason, this story really took off.

“I received many phone calls and letters from women asking me whether they caused their child to have diabetes because they didn’t want to breastfeed, or whether they were selfish for going back to work. It caused a lot of anxiety.”

The Lancet article features Atkinson’s review of research over many years — studies he says were fundamentally flawed in their methodology and conclusions. Some, for example, relied on questionnaires asking people to recall events from 10 to 15 years earlier. Others did not accurately separate and analyze early infant feeding practices such as intermittent consumption of breast milk and infant formula.

Furthermore, epidemiological studies refute the link between cow’s milk and diabetes, Atkinson said. He noted, for example, that people in Finland drink twice as much cow’s milk as people in Sardinia, but the two countries have similar incidence of insulin-dependent diabetes.

Greatly expanded and properly designed trials are needed to properly address the issue, he said. Yet early data from patient studies in Finland and Canada comparing children who consume formula with cow’s milk protein versus those consuming formula without cow’s milk already contradict the purported link between formula feeding and diabetes. In the Finland trial, an infant who consumed formula that did not contain cow’s milk has developed diabetes.

UF researchers, therefore, believe attempts to modify infant diets with the aim of avoiding diabetes have been “premature and unnecessary.”

“Although breastfeeding is worth encouraging for many reasons, we strongly believe current infant feeding guidelines should not be changed with the aim of avoiding insulin-dependent diabetes until more convincing evidence accumulates on the particular link between foods and diabetes,” Atkinson said.

“We also need more information on important features of how long a person is exposed to these foods, and a description of the mechanism by which they may promote the development of diabetes.”