Objectives: To investigate the relationship of specific nutrients and food items with oral precancerous lesions among tobacco users.
Design: A population-based case-control study.
Setting: Villages in Palitana taluk of Bhavnagar district, Gujarat, India.
Subjects and methods: An interviewer-administered food frequency questionnaire, developed and validated for this population, was used to estimate nutrient intake in blinded, house-to-house interviews. Among 5018 male tobacco users, 318 were diagnosed as cases. An equal number of controls matched on age (+/- 5 years), sex, village, and use of tobacco were selected.
Main outcome measures: Odds ratios (OR) from multiple logistic regression analysis controlling for relevant variables (type of tobacco use and economic status).
Results: A protective effect of fibre was observed for both oral submucous fibrosis (OSF) and leukoplakia, with 10% reduction in risk per g day-1 (P < 0.05). Ascorbic acid appeared to be protective against leukoplakia with the halving of risk in the two highest quartiles of intake (versus the lowest quartile: OR = 0.46 and 0.44, respectively; P < 0.10). A protective effect of tomato consumption was observed in leukoplakia and a suggestion of a protective effect of wheat in OSF.
Conclusion: In addition to tobacco use, intake of specific nutrients may have a role in the development of oral precancerous lesions.