Diet and Childhood Cancer: Preliminary Evidence

Key Points

• The relationship of mother’s, father’s, and child’s diet with risk of childhood cancer is not well studied and not well understood.

• High intake of cured meats during pregnancy has been consistently associated with increased risk of brain tumors in children. However, other explanations of the observations, such as dietary or other confounders, have not been ruled out.

• Vitamin supplement use may decrease the risk of several childhood cancers; however due to the unidentified critical time period of exposure and specific nutrient(s), these findings must be considered inconclusive.

Abstract

The role of diet in the etiology of cancer in children is not well studied. Based on animal data, epidemiologists hypothesized that gestational exposure to N-nitroso compounds increases the risk of brain tumors in children. The hypothesis predicts that cured meats, which contain N-nitroso compounds and precursors that form these compounds in vivo, increase risk. The evidence supports an association between frequent eating of cured meat by the mother during pregnancy and increased risk in the child. However, as only dietary factors related to this hypothesis were studied, the possibility exists that correlated dietary characteristics explain the finding. The evidence is not as strong for other aspects of the N-nitroso hypothesis, for example, that high vitamin C intake decreases risk because it inhibits synthesis from precursors. Thus, some findings on brain tumors support the N-nitroso hypothesis but are also consistent with other mechanisms. Although leukemia is more common than brain tumors in children, fewer studies have addressed the role of diet. Some evidence supports an etiologic role during gestation of foods containing naturally occurring DNA topoisomerase II inhibitors for acute myeloid leukemia with an MLL gene rearrangement in infants, a small subset of childhood leukemia. Recent studies of all childhood leukemia suggest that some aspects of a healthy diet are protective, but replication of these findings is needed. For brain tumors, leukemia, neuroblastoma, and retinoblastoma, protective effects of multivitamin supplements during pregnancy have been observed. Replication and the identification of the critical time period are needed. Although data on the role of diet in childhood cancer are sparse and inconclusive, early evidence suggests that a healthy diet and multivitamins during gestation may reduce risk.