Association between aflatoxin-albumin adduct levels and tortilla consumption in Guatemalan adults

Aflatoxin B₁ (AFB₁) is a known human hepatocarcinogen and a recent study reported elevated AFB₁ levels, measured by serum albumin biomarkers, among Guatemalan adults. While AFB₁ can contaminate a variety of foodstuffs, including maize, Guatemala's main dietary staple, the relationship of maize intake to serum AFB₁-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 AFB₁-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 AFB₁-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 AFB₁-albumin levels. However, there was a statistically significant association between tortilla consumption and AFB₁-albumin levels (p_trend = 0.01). The LSM of AFB₁-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 AFB₁ exposure in the Guatemalan population. Therefore, efforts to control or mitigate AFB₁ levels in contaminated maize used for tortillas may reduce overall exposure in this population.