Association Between Aflatoxin-albumin Adduct Levels and Tortilla Consumption in Guatemalan Adults

Aflatoxin B (AFB) is a known human hepatocarcinogen and a recent study reported elevated AFB levels, measured by serum albumin biomarkers, among Guatemalan adults. While AFB can contaminate a variety of foodstuffs, including maize, Guatemala's main dietary staple, the relationship of maize intake to serum AFB-albumin adducts levels in Guatemala has not been previously examined. As a result, a cross-sectional study was conducted among 461 Guatemalan adults living in five geographically distinct departments of the country. Participants provided a serum sample and completed a semi-quantitative food frequency questionnaire and a sociodemographic questionnaire. Multiple linear regression analysis was used to estimate the least square means (LSQ) and 95% confidence intervals (95% CI) of log-transformed AFB-albumin adducts by quintiles of maize consumption in crude and adjusted models. Additionally, analyses of tortilla consumption and levels of maize processing were conducted. The median maize intake was 344.3 g per day [Interquartile Range (IQR): 252.2, 500.8], and the median serum AFB-albumin adduct level was 8.4 pg/mg albumin (IQR: 3.8, 22.3). In adjusted analyses, there was no association between overall maize consumption and serum AFB-albumin levels. However, there was a statistically significant association between tortilla consumption and AFB-albumin levels (p = 0.01). The LSM of AFB-albumin was higher in the highest quintile of tortilla consumption compared to the lowest quintile [LSM:9.03 95%CI: 7.03,11.70 vs 6.23, 95%CI: 4.95,8.17, respectively]. These findings indicate that tortilla may be an important source of AFB exposure in the Guatemalan population. Therefore, efforts to control or mitigate AFB levels in contaminated maize used for tortillas may reduce overall exposure in this population.