NovaSil clay intervention in Ghanaians at high risk for aflatoxicosis: II. Reduction in biomarkers of aflatoxin exposure in blood and urine

Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2008 May;25(5):622-34. doi: 10.1080/02652030701598694.


The efficacy of NovaSil clay (NS) to reduce aflatoxin (AF) biomarkers of exposure was evaluated in 656 blood samples and 624 urine samples collected from study participants during a 3-month phase IIa clinical intervention trial in Ghana. NS was delivered before meals via capsules. Serum AFB (1)-albumin adduct was measured by radioimmunoassay and urinary AFM (1) metabolites were quantified by immunoaffinity-high-performance liquid chromatography (HPLC)-fluorescence methods. Levels of AFB (1) -albumin adduct in serum samples collected at baseline and at 1 month were similar (p = 0.2354 and p = 0.3645, respectively) among the placebo (PL), low dose (LD, 1.5 g NS day (-1)), and high dose (HD, 3.0 g NS day (-1)) groups. However, the levels of AFB (1)-albumin adduct at 3 months were significantly decreased in both the LD group (p < 0.0001) and the HD group (p < 0.0001) compared with levels in the PL group. Levels of AFM(1) in urine samples collected at baseline and at 1 month were not statistically different among the three study groups. However, a significant decrease (up to 58%) in the median level of AFM (1) in samples collected at 3 months was found in the HD group when compared with the median level in the PL group (p < 0.0391). In addition, significant effects were found for dose, time, and dose-time interaction with serum AFB(1)-albumin adduct and dose-time interaction with urinary AFM (1) metabolites. The results suggest that capsules containing NS clay can be used to reduce effectively the bioavailability of dietary AF based on a reduction of AF-specific biomarkers.

Publication types

  • Clinical Trial, Phase II
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aflatoxins / blood*
  • Aflatoxins / poisoning
  • Aflatoxins / urine*
  • Aluminum Silicates / administration & dosage*
  • Biomarkers / blood
  • Biomarkers / urine
  • Clay
  • Double-Blind Method
  • Food Additives / administration & dosage*
  • Ghana
  • Humans
  • Male
  • Middle Aged
  • Risk Factors
  • Statistics as Topic


  • Aflatoxins
  • Aluminum Silicates
  • Biomarkers
  • Food Additives
  • Clay