Breastfeeding is what gives infants the immunities they need so that until their digestive track and naturally immunities can fully develop. Even if mothers choose to breastfeed for only a short amount of time, it’s better than no time at all. In fact, a study conducted in 2012 revealed that infants who were only formula fed had a greater risk of developing pediatric acute lymphoblast leukemia. This risk was exacerbated further if the mother also introduced solid foods later than normal.

The findings of the study were presented by Jeremy Schraw, a graduate student at The University of Texas at Austin. At the 11th Annual AACR International Conference on Frontiers in Cancer Prevention Research in 2012, Schraw stated that "For every month that a child was fed formula, taking into account other feeding practices, we found that the risk for this type of cancer was higher. If a baby is fed only formula, he or she will not be getting any immune factors from the mother, which could be leading to this greater risk."

Along with a group of colleagues, Schraw examined 426 children. Two hundred and eighty-four of the children were a part of the control group, and 142 children were from the Texas Children's Cancer Center and the National Children's Study in Houston, San Antonio, and Austin, Texas, who had been diagnosed with acute lymphoblastic leukemia (ALL).

It was found the children with ALL started solid foods considerably later than the children in the control group and they were also formula fed for a much longer period. It was also found that many of the children in the ALL group had mothers who smoked during pregnancy as well. Based on the gathered evidence, it was discovered that the risk of developing ALL rose by 16% every month that the children were formula fed instead of breastfed. Along with this, for every month that solid food consumption was delayed, the risk of ALL increased by another 14%.

"One explanation for this co-risk may be that it's the same effect being picked up twice," said Schraw. "Children being given solid foods later may be receiving formula longer." Schraw and his team suggest that research done in the future on this relationship should consider factors that influence prolonged formula use and delays in introducing solid food consumption.

Source: American Association for Cancer Research (AACR) (2012, October 17). Prolonged formula feeding, delay in solid foods was associated with increased risk for pediatric acute lymphoblastic leukemia. ScienceDaily.