DIETARY FACTORS AND THE RISK OF GLIOMA IN ADULTS - RESULTS OF A CASE-CONTROL STUDY IN MELBOURNE, AUSTRALIA

In a population-based case-control study of 416 incident gliomas in ad ults carried out in Melbourne, Australia, between 1987 and 1991, 409 a ge-sex-matched case-control pairs (243 male and 166 female) had adequa te data available to examine associations between the dietary intake o f N-nitroso compounds, N-nitroso precursors, other nutrients including N-nitroso inhibitors, and the risk of glioma. Dietary intakes were ba sed on the reported frequency of consumption of 59 food items. Increas ed odds ratio (OR) were observed in males who consumed high levels of bacon, corned meats, apples, melons and oil. OR less than unity were o bserved in men consuming cabbage and cola drinks, and in women who con sumed wholegrain bread, pasta, corned meat, bananas, cauliflower, broc coli, cola drinks and nuts. Generally, N-nitroso associations were gre ater in men and micronutrient associations were greater in women. Elev ated OR in men, but not women, were associated with the intake of N-ni troso dimethylamine (NDMA), retinol and vitamin E. The intake of nitra te (largely of vegetable origin) was protective in women but not in me n. When analyzed using multiple logistic regression, the association w ith NDMA intake in males was not modified by dietary micronutrient int akes. In females, beta carotene alone, though not directly associated with risk, modified the effect of NDMA. On balance, this study added o nly limited support to the N-nitroso hypothesis of glial carcinogenesi s. (C) 1994 Wiley-Liss, Inc.