Index-based dietary patterns and risk of head and neck cancer in a large prospective study.

BACKGROUND: Head and neck cancer (HNC) is the seventh most common cancer worldwide. Although diet has been proposed to play an important role in HNC, few associations with diet have been convincing other than alcohol intake. Studies of dietary patterns that examine overall diets may provide broader insight than studies of individual foods. Little is known about the association between dietary patterns and risk of HNC.
OBJECTIVE: We prospectively evaluated the association between 2 index-based dietary patterns [ie, the Healthy Eating Index-2005 (HEI-2005) and alternate Mediterranean Diet Score (aMED)] and risk of head and neck squamous cell carcinoma.
DESIGN: We included 494,967 participants from the NIH-AARP Diet and Health study (1995-2006). HRs (95% CIs) were estimated by using Cox regression. Scores for the HEI-2005 and aMED were calculated on the basis of diet assessed by using a baseline food-frequency questionnaire. Higher scores reflected adherence to dietary recommendations for healthy eating. Our main outcome was the incidence of HNC, including cancer of the larynx, oral cavity, and orohypopharynx.
RESULTS: A total of 1868 HNC cases were identified during follow-up. Higher HEI-2005 scores were associated with reduced risk of HNC in men [HR: 0.74 (95% CI: 0.61, 0.89) for highest compared with lowest quintiles; P-trend = 0.0008] and women [HR: 0.48; 95% CI: 0.33, 0.70; P-trend < 0.0001]. High aMED scores were also associated with lower HNC risk in men (HR: 0.80; 95% CI: 0.64, 1.01; P-trend = 0.002) and women (HR: 0.42; 95% CI: 0.24, 0.74; P-trend < 0.0001). Associations were similar among subsites. We did not find significant interactions between smoking and alcohol intake and each index on HNC risk.
CONCLUSIONS: HEI-2005 and aMED scores were associated inversely with risk of HNC. Large interventional studies are required to assess the causality before conveying definite public health messages.