Micronutrients: Measurements from Validated Data and Association with Oral Cancer

Objective:  To examine the association between micronutrient (retinol, a-tocopherol and b-carotene) intake as measured by food frequency questionnaire and corresponding measurement in blood serum and to determine the association between micronutrient and risk of oral cancer in the Malaysian population. Method:  This is a case control study involving multi-centre/hospital based patients.This study included 120 oral cancer cases and 120 controls matched for age, gender and ethnicity. Serum samples, socio-demographic and dietary data were obtained from the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). Two measurement tools were used to measure micronutrient intake. The first measurement is taken from blood serum, while the second is taken using data gathered from a specific food frequency questionnaire (FFQ). Micronutrients from serum were extracted with hexane and examined using high performance liquid chromatography (HPLC) while data from the FFQ was converted to daily nutrient intake by the NutrieMart software. The correlation between the two methods used was analysed using Pearson correlation coefficient and the association of micronutrients with oral cancer risk was examined using multiple logistic regression. Result:  This study found that the two methods applied were not correlated. Meanwhile, logistic regression analysis showed that retinol (OR = 0.501, 95% CI = 0.254 – 0.992, p < 0.05) and α-tocopherol (OR = 0.184, 95% CI = 0.091 – 0.370, p < 0.05) was significantly related to lower risk of oral cancer, whereas, no relationship was observed between serum level of β-carotene and oral cancer risk. Conclusion: This study concluded that biochemical assessment and dietary assessment using FFQ serves different purposes and cannot be used interchangeably. This study also found that high level of serum retinol and α-tocopherol provides protection against oral cancer.