Corn Flour Intake, Aflatoxin B1 Exposure, and Risk of Esophageal Precancerous Lesions in a High-Risk Area of Huai’an, China: A Case-Control Study

Aflatoxin B1 (AFB1), which has potent toxicity and carcinogenicity, is a common contaminant of important agricultural commodities. This study aimed to investigate the frequency of corn flour intake and assess the exposure to AFB1 via direct detection of AFB1 in the diet and serum AFB1 exposure biomarker, so as to evaluate their associations with the risk of esophageal precancerous lesions (EPL). A case-control study based on three-day duplicate diet samples was performed in Huai’an District. One hundred EPL cases and 100 healthy controls were enrolled and required to be age- (±2 years) and gender-matched. The concentration of AFB1 in food samples and the level of serum AFB1-albumin (AFB1-Alb) adduct were quantitatively analyzed. Results showed that corn flour intake was positively associated with serum AFB1-Alb adduct level (p for trend = 0.003), dietary AFB1 exposure (p for trend < 0.001), and the risk of EPL (p for trend = 0.017). Increased serum AFB1-Alb adduct level was associated with an increased risk of EPL as well (p for trend < 0.001). In conclusion, corn flour may be an essential source of AFB1 in Huai’an District, whereas high exposure to AFB1 is likely to be an important risk factor contributing to the progression of EPL.