Consumption of fruit, vegetables, and other food groups and the risk of nasopharyngeal carcinoma

PURPOSE: The role of dietary habits in the etiology of nasopharyngeal carcinoma (NPC) has been extensively investigated in high-incidence areas, but evidence is scanty in low-incidence populations. This study aimed to investigate the relationship between NPC risk and a wide range of food groups in the Italian population. METHODS: We conducted a hospital-based case-control study in Italy on 198, histologically confirmed, NPC cases of Caucasian ethnicity, aged 18-76 years. Controls were 594 Caucasian cancer-free patients admitted to general hospitals for acute conditions. Odds ratios (ORs) and the corresponding confidence intervals (CIs) were estimated through logistic regression, adjusting for socio-demographic characteristics, tobacco smoking, alcohol drinking, and energy intake. RESULTS: Elevated vegetable consumption was inversely related to NPC risk (OR for highest vs. lower quartile = 0.51; 95 % CI 0.29-0.90). The association was particularly strong for yellow- or red-pigmented vegetables (OR = 0.31; 95 % CI 0.18-0.54), and this effect was stronger among never smokers (OR = 0.18; 95 % CI 0.06-0.55) than among ever smokers (OR = 0.37; 95 % CI 0.19-0.71). Increased NPC risk emerged for elevated eggs consumption (OR = 2.50; 95 % CI 1.44-4.32; p-trend <0.01). No significant associations emerged between NPC risk and consumption of cereals, meat, fish, dairy products, and sweets. CONCLUSIONS: The study findings show that, also in low-risk populations, vegetable consumption is a protective factor against NPC. The stronger effect for yellow- or red-pigmented vegetables is in agreement with the inverse association reported for carotenoids intake.