Adherence to the Mediterranean diet and nasopharyngeal cancer risk in Italy.

PURPOSE: Few studies investigated the role of diet on nasopharyngeal cancer (NPC) risk in non-endemic areas. The aim of this study was to assess the association between adherence to the traditional Mediterranean diet and NPC risk in a southern European low-risk population.

METHODS: We conducted a hospital-based case-control study in Italy, including 198 histologically confirmed NPC cases and 594 matched controls. Dietary habits were collected by means of a validated food-frequency questionnaire, including 83 foods, food groups, or beverages. Adherence to the traditional Mediterranean diet was assessed through a Mediterranean Diet Score (MDS), based on nine dietary components characterizing this dietary profile, i.e., high intake of vegetables, fruits and nuts, cereals, legumes, and fish; low intake of dairy products and meat; high monounsaturated to saturated fatty acid ratio; and moderate alcohol intake. We estimated odds ratios (ORs) of NPC, and the corresponding 95% confidence intervals (CIs), for increasing MDS (i.e., increasing adherence) using multiple logistic regression models, adjusted for major confounding factors.

RESULTS: As compared to MDS ≤ 4, the ORs of NPC were 0.83 (95% CI: 0.54-1.25) for MDS of 5 and 0.66 (95% CI: 0.44-0.99) for MDS ≥ 6, with a significant trend of decreasing risk (p 0.043). The corresponding population attributable fraction was 22%, indicating that 22% of NPC cases in this population would be avoided by shifting all subjects to a score ≥6.

CONCLUSIONS: Our study supports a favorable role of the Mediterranean diet on NPC risk.