Adherence to the Mediterranean Diet and the Risk of Head and Neck Cancer: A Systematic Review and Meta-Analysis of Case-Control Studies.

Abstract

Background/objectives: Head and neck cancer (HNC) is the seventh most common cancer worldwide, with rising incidence rates and significant mortality. While tobacco use, alcohol consumption, and viral infections are established risk factors, the role of dietary patterns, particularly adherence to the Mediterranean diet (MD), in HNC prevention has gained increasing attention. The aim of the current systematic review and meta-analysis is to investigate the association between adherence to the MD and the risk of HNC.

Methods: A comprehensive search was conducted, following PRISMA guidelines, to identify relevant studies published up to January 2024 that assessed the association between MD adherence and HNC risk in adults. Pooled odds ratios (OR) for a three-unit increase in MD adherence scores and corresponding 95% confidence intervals (CI) were calculated using a random-effects model. Study quality was assessed using the Newcastle-Ottawa Scale (NOS).

Results: Eleven case-control studies comprising 6106 HNC cases and 9166 controls met the inclusion criteria for the systematic review. High adherence to the MD was significantly associated with a reduced risk of HNC (pooled OR = 0.561, 95% CI: 0.368-0.856, p = 0.007, I² = 92%). Individual component analyses from three studies revealed that higher fruit and vegetable consumption significantly decreased HNC risk, whereas legumes, fish, and low meat intake showed no statistically significant associations.

Conclusions: Adherence to the Mediterranean diet is associated with a significantly reduced risk of head and neck cancer. These findings support the role of the MD in cancer prevention and highlight the potential benefits of MD adherence in reducing HNC risk. Further prospective studies and randomized controlled trials are needed to confirm these findings and explore the underlying mechanisms.