The Molecular Epidemiology of Chronic Aflatoxin Driven Impaired Child Growth

Abstract

Aflatoxins are toxic secondary fungal metabolites that contaminate dietary staples in tropical regions; chronic high levels of exposure are common for many of the poorest populations. Observations in animals indicate that growth and/or food utilization are adversely affected by aflatoxins. This review highlights the development of validated exposure biomarkers and their use here to assess the role of aflatoxins in early life growth retardation. Aflatoxin exposure occurs in utero and continues in early infancy as weaning foods are introduced. Using aflatoxin-albumin exposure biomarkers, five major studies clearly demonstrate strong dose response relationships between exposure in utero and/or early infancy and growth retardation, identified by reduced birth weight and/or low HAZ and WAZ scores. The epidemiological studies include cross-sectional and longitudinal surveys, though aflatoxin reduction intervention studies are now required to further support these data and guide sustainable options to reduce the burden of exposure. The use of aflatoxin exposure biomarkers was essential in understanding the observational data reviewed and will likely be a critical monitor of the effectiveness of interventions to restrict aflatoxin exposure. Given that an estimated 4.5 billion individuals live in regions at risk of dietary contamination the public health concern cannot be over stated.

Aflatoxin Exposure During Pregnancy, Maternal Anemia, and Adverse Birth Outcomes

“…There are three validated biomarkers of aflatoxin exposure: urinary biomarkers reflecting exposure in the prior 24–48 hours (AFM1 and aflatoxin-N7-guanine) and serum biomarkers reflecting cumulative exposure over the prior 2–3 months (AF-alb). These biomarkers are all quantitatively associated with dietary aflatoxin intake 40. Other aflatoxin metabolites (e.g., serum AFM1 or AFG1, urinary AFB1 or AFG1, and milk AFM1 or AFG2) are indicative of exposure, but levels do not correlate with dietary intake and they are therefore termed biomeasures.…”

Adult height, nutrition, and population health

“…Environmental exposures in poor socioeconomic areas, such as the consumption of aflatoxin, may also retard growth. 110,111 The dependence of height on socioeconomic circumstances, however, may lessen as populations become wealthier. For example, the socioeconomic gradient in adult height, though still existing, decreased (by about 2 cm) among Swedish men from 1818 to 1968.…”

Mykotoxine in Lebensmitteln

“…Sie werden von Schimmelpilzarten der Gattung Aspergillus (A. flavus und A. parasiticus) gebildet, die vor allem in Regionen mit feuchtwarmem Klima anzutreffen sind. Die Erforschung der Aflatoxine (AF), ihrer Schadwirkungen und der Präventions-strategien sind in Reviews beschrieben [10][11][12]. Akute Vergiftungen und sehr hohe Leberkrebsinzidenzen finden sich insbesondere in Regionen in Afrika und Südostasien, wo die Aflatoxinkontamination von Nahrungsmitteln weiterhin eine große Rolle spielt.…”

“…Aber auch in Deutschland wurde 1973 über einen Todesfall infolge akuten Leberversagens nach Verzehr von kontaminierten Paranüssen berichtet [13]. Die am stärksten toxischen Schimmelpilzgifte sind AFB1 und AFG1 sowie der im Organismus gebildete hydroxylierte Metabolit AFM1, den Mensch und Tier nach AFB1-Aufnahme mit Milch und Urin ausscheiden [11,12]. AFM1 ist etwa um den Faktor 10 weniger potent als AFB1; es kann in analoger Weise wie AFB1 und AFG1 bioaktiviert werden (s. unten) und ist im Tierversuch kanzerogen wirksam.…”