Breastfeeding and type 1 diabetes prevention

June 2004 – Children who are exclusively breastfed for a long period of time may be at lower risk of developing type 1 diabetes than those who are not, according to a Swedish study.

Most children with diabetes have type 1 diabetes. With this condition, the pancreas loses its ability to produce any or enough insulin. Insulin is needed for bodies to make energy from foods eaten. In Canada, about 1 in 300 to 400 school-aged children have diabetes.

Researchers compared the data from 517 children in southeastern Sweden and 286 children in Lithuania who had been newly diagnosed with type 1 diabetes with children without diabetes. The children ranged in age from 0 to 15. Information was gathered through questionnaires.

Results showed that the longer children were breastfed exclusively tended to have a protective effect on developing type 1 diabetes in both countries. This was particularly true in exclusive breastfeeding longer than five months, total breastfeeding longer than 7 or 9 months, and with breastfeeding substitution that started later than the seventh month. Interestingly, though, while mothers in Sweden tend to breastfeed longer than mothers in Lithuania, the incidence of diabetes is higher.

The researchers also found that postponing new foods and cow’s milk seemed to be protective against the development of type 1 diabetes.

Recently, studies have shown breastfeeding can reduce a person's risk of developing high blood pressure, obesity, and cardiovascular disease. It is possible that colostrum, the protein-rich fluid breasts produce before milk comes in, may protect children from infection and inflammation that can trigger chronic conditions.

Another theory is that breastfed children tend to grow more slowly and steadily while formula-fed babies often have growth spurts. That is because mother's milk contains fewer calories than formula.

In evaluating the study, Jennifer Buccino, a registered dietitian and certified diabetes educator at the Hospital for Sick Children, indicated that the findings are weak. There was a tendency to see fewer children developing diabetes but not by that much.

Until a longer, prospective study is done, current recommendations are not likely to change. “Nursing mothers should continue to follow the guidelines from Health Canada regarding breastfeeding,” according to Buccino. “The current recommendation is to breastfeed exclusively for the first 4 months of life.”

She noted that the World Health Organization recommends exclusive breastfeeding for the first 6 months and then continuing breastfeeding while introducing new foods up to 2 years of age.

The take-home message, Buccino concluded, is, “while there is evidence to suggest that breastfeeding is beneficial to a baby's health and may have added benefits over formula in some areas, such as reducing the risk of allergies, formula fed babies can also grow and develop normally.”