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

Aflatoxins are mycotoxins produced by naturally occurring fungi on food, and aflatoxin B₁ (AFB₁) is carcinogenic, immunotoxic and hepatotoxic. This study assesses the relationship between AFB₁ in Nepali infants at 12 months of age and their diet at 9 and 12 months of age.

The study used data collected from 1329 infants enrolled in the AflaCohort Study. Aflatoxin exposure was assessed at 12 months using serum AFB₁-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 AFB₁) and contemporaneous (12-month diet and 12-month AFB₁) associations.

Eighty-one percent of children at 12 months had detectable levels of serum AFB₁-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 AFB₁-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 AFB₁-lysine while consumption of bananas and mangoes at 12 months were negatively associated with serum AFB₁-lysine (p < 0.05).

High prevalence of detectable AFB₁-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.