Childhood cancer in relation to cured meat intake: Review of the epidemiological evidence

Over the past two decades a series of epidemiological studies have examined the relationship between consumption of cured meats during pregnancy and t he subsequent risk of brain tumors, as well as other cancers, in the offspr ing. The research was prompted in large part by experimental investigations showing that transplacental exposure to certain N-nitroso compounds, i.e., nitrosoureas, could produce brain tumors in laboratory animals. Fourteen s uch epidemiological studies, 13 of which used the case-control approach, ar e reviewed here. Most of the studies showed no significant association betw een total cured meat intake and childhood cancer risk but more found positi ve than negative relationships. Furthermore, several studies reported signi ficant positive associations for maternal and sometimes childhood or patern al consumption of one or more cured meats, with odds ratios of twofold or g reater reported among the highest consumers. On the other hand a correlatio n analysis found no positive concordance between temporal trends from the 1 970s to 1990s in childhood brain cancer rates and cured meat consumption in asmuch as cancer rates rose over time while residual nitrite levels in cure d meats fell sharply. Because of the potential for bias, especially recall bias, and/or confounding, the relatively weak magnitude of the associations reported, and the inconsistency between study findings, at this time it ca nnot be concluded that eating cured meat has increased the risk of childhoo d brain cancer or any other cancers. Moreover, although N-nitroso compounds are sometimes found in cured meats or may be formed endogenously there is no empirical evidence that eating cured meats results in human neural nitro sourea exposure. Nevertheless, the hypothesis that eating nitrite-cured mea ts may influence childhood and perhaps adult brain cancer cannot be dismiss ed. Unbiased evaluation of the hypothesis may derive from the conduct of co hort studies, where the interview-derived information on cured meat intake precedes, or is nor otherwise associated with, the diagnosis of cancer.