Food intake and the risk of oral squamous cell carcinoma: a case–control study in Iran

Oral squamous cell carcinoma (OSCC) is a major cancer of the head and neck, with particularly high incidence reported across parts of Asia. While lifestyle-related risk factors are well established for many cancers, the influence of diet on OSCC remains less clear, especially in Asian populations. In Iran and similar Asian settings, everyday food choices are deeply influenced by culture and economy, making it vital to understand how they might influence cancer risk. The aim of this study is investigation of the association between nutrient intakes and the risk of oral squamous cell carcinoma (OSCC). In this case–control study, 100 newly diagnosed OSCC cases and 200 healthy individuals matched for age, sex, tobacco, and alcohol use were included. Dietary intake was assessed through a validated food frequency questionnaire, and nutrient values were calculated using Nutritionist 4 software. Multivariable logistic regression models were used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). All models were adjusted for the following confounding variables: age (continuous, years), sex (male/female), smoking status (yes/no), alcohol use (yes/no), and body mass index (BMI, continuous, kg/m 2 ). Consumption of saturated fat (OR = 1.27; 95% CI: 1.16–1.41; p < 0.001), linoleic acid (p < 0.001; OR = 1.35, 95% CI: 1.16–1.59), soluble fibers (p < 0.001; OR = 0.01, 95% CI: 0.01–0.11), fructose (OR = 1.17; 95% CI: 1.06–1.30; p = 0.002) and sucrose (OR = 1.16; 95% CI: 1.07–1.26; p < 0.001), was higher in the OSCC group. Conversely, greater protein intake was linked to a modest but statistically significant reduction in OSCC risk (P < 0.001; OR = 0.91, 95% CI: 0.87–0.94). No significant differences have been reported in age, sex, alcohol and tobacco use between case and control group. Diets rich in fats and sugars but low in protein may be associated with higher OSCC risk, whereas adequate protein consumption was associated with a protective effect. While some nutrients showed only modest effects, they are so common in the local diet that even small shifts in risk could have a great effect on public health.