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

Abstract

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.

Keywords: Aflatoxin B1 exposure; corn flour intake; duplicate diet; esophageal precancerous lesion; serum biomarker.

Figure 1

Location of Huai’an District in China. Reprinted from Map of Huai’an District by Bajiu internet services, 29 March 2020, retrieved from https://bajiu.cn/ditu/?qh=20671. Copyright 2006–2020 by Bajiu internet services. Texts and indicators were added with Microsoft Word 2007 (Microsoft Inc., Redmond, WA, USA) (https://www.microsoft.com/en-us/).

Figure 2

Box and whiskers plot of serum AFB₁-Alb adduct level in EPL cases and healthy controls. The box values range from 25 to 75 percentiles. The line within the box represents the median. The T-shaped bars at both sides of the box represent 5 and 95 percentiles of data. The dots and asterisks represent outliers and extremes, respectively.

Figure 3

Scatter plot of correlation between dietary AFB₁ exposure and serum AFB₁-Alb adduct level. Each dot’s horizontal position indicates a subject’s dietary AFB₁ exposure (in μg/d) and the vertical position indicates the subject’s serum AFB₁-Alb adduct level (in pg/mL).