Dietary determinants of aflatoxin B1-lysine adduct among infants in Nepal.

Background: Aflatoxins are mycotoxins produced by naturally occurring fungi on food, and aflatoxin B (AFB) is carcinogenic, immunotoxic and hepatotoxic. This study assesses the relationship between AFB in Nepali infants at 12 months of age and their diet at 9 and 12 months of age.

Methods: The study used data collected from 1329 infants enrolled in the AflaCohort Study. Aflatoxin exposure was assessed at 12 months using serum AFB-lysine pg/mg albumin biomarker measured using high performance liquid chromatography-fluorescent detection. Dietary data were collected using food frequency questionnaire. We conducted ordinary least squares and quantile regression analyses with backward elimination to assess lagged (9-month diet and 12-month AFB) and contemporaneous (12-month diet and 12-month AFB) associations.

Results: Eighty-one percent of children at 12 months had detectable levels of serum AFB-lysine (geometric mean: 0.79 pg/mg albumin, 95% CI: 0.74-0.83). The levels ranged from 0.4 to 85 pg/mg albumin. Dietary diversity at 9 and 12 months were not associated with serum AFB-lysine levels. Consumption of fish and groundnuts at both 9 and 12 months and infant formula and cauliflower at 9 months were associated with higher serum AFB-lysine while consumption of bananas and mangoes at 12 months were negatively associated with serum AFB-lysine (p < 0.05).

Conclusions: High prevalence of detectable AFB-lysine among infants, and possible links to their dietary patterns argues for more urgent research into which foods in children's diets are most contaminated, and into optimal entry points in the food chain that would allow for effective actions to minimize exposure.