The Impact of Food-Based Composite Dietary Antioxidant Intake and Lung Cancer Risk: Findings from the Singapore Chinese Health Study

Background. The protective effect of a balanced diet on lung cancer risk has been well established in the literature. However, a limited amount of research exists on the role of food-based antioxidant intake on lung cancer risk, especially among an Asian population. Methods. The Singapore Chinese Health Study (SCHS) is an ongoing prospective cohort study with 61,321 participants aged 47-74 years old at baseline. Using this data, we evaluated the association between the Composite Dietary Antioxidant Index (CDAI) and lung cancer risk. A Cox proportional hazard regression model was used to estimate hazard ratio (HR) and the corresponding 95% confidence interval (CI) for lung cancer risk in relation to CDAI scores, after adjusting for confounders. Results. In the SCHS cohort, 2,008 participants developed lung cancer after an average of 17.5 years of follow-up. No significant association between CDAI score and lung cancer cases. After stratification histologic subtype, smoking status, alcohol consumption, BMI, and diabetes history, we found a significant association between the fourth quartile range of CDAI scores and increased lung squamous cell carcinoma risk among never smokers (HR=6.17; 95% CI: 1.27-30.0; Ptrend=0.06). Further analyses into the association between CDAI scores and lung cancer risk by second-hand smoke exposure stratification did not reveal significant results. Conclusion. Additional work in this area of research needs to be done among the Asian population to clearly define this association. The public health relevance of the issue is evident given the limited used of the CDAI as a predictor of lung cancer risk. As more conclusive research is conducted, lung cancer prevention recommendations for the general public, specifically on the effect food-based antioxidant intake on lung cancer risk, can be revised