Short-term safety evaluation of processed calcium montmorillonite clay (NovaSil) in humans

• Published in: Food additives and contaminants 2005-03, Vol.22 (3), p.270-279
• Main Authors: Wang, J.S, Luo, H, Billam, M, Wang, Z, Guan, H, Tang, L, Goldston, T, Afriyie-Gyawu, E, Lovett, C, Griswold, J
• Format: Article
• Language: English
• Subjects: Administration, Oral; Adult; Aflatoxins; Aflatoxins - metabolism; anticaking additive; Bentonite - administration & dosage; Bentonite - adverse effects; Bentonite - analysis; binding capacity; Biological and medical sciences; Blood Cell Count - methods; Blood Chemical Analysis - methods; calcium; clinical trial; clinical trials; Double-Blind Method; feed additives; Female; Food Additives - administration & dosage; Food Additives - adverse effects; Food Additives - analysis; food contamination; Food industries; Food toxicology; Fundamental and applied biological sciences. Psychology; Gastrointestinal Diseases - chemically induced; General aspects; geophagia; Humans; Hygiene and safety; intestinal absorption; Male; Middle Aged; Minerals - blood; montmorillonite; NovaSil clay; risk reduction; safety evaluation; safety testing; secondary metabolites; toxigenic strains; Vitamin A - blood; Vitamin E - blood
• ISSN: 0265-203X; 1464-5122
• DOI: 10.1080/02652030500111129

NovaSil clay (NS) provides significant protection from the adverse effects of aflatoxins (AFs) in multiple animal species by decreasing bioavailability from the gastrointestinal tract. It is postulated that NS clay can be safely added to human diets to diminish exposure and health risks from AF contaminated food. To determine the safety and tolerance of NS in humans and establish dosimetry protocols for long-term efficacy studies, a randomized and double-blinded phase I clinical trial was conducted. Volunteers (20-45 yr in age), were clinically screened for confirmation of their health status. Fifty subjects (23 males and 27 females) were randomly divided into two groups: The low-dose group received nine capsules containing 1.5 g/day, and the high-dose group received nine capsules containing 3.0 g/day for a period of 2 wk. NS capsules were manufactured in the same color and size and were distributed to each participant three times a day at designated sites where follow-up was taken to record any side effects and complaints. Blood and urine samples were collected before and after the study for laboratory analysis. All participants completed the trial and compliance was 99.1%. Mild GI effects were reported in some participants. Symptoms included abdominal pain (6%, 3/50), bloating (4%, 2/50), constipation (2%, 1/50), diarrhea (2%, 1/50), and flatulence (8%, 4/50). No statistical significance was found between the two groups for these adverse effects (p > 0.25). No significant differences were shown in hematology, liver and kidney function, electrolytes, vitamins A and E, and minerals in either group. These results demonstrate the relative safety of NS clay in human subjects and will serve as a basis for long-term human trials in populations at high risk for aflatoxicosis.