On November 13, 2009, Dr. Timothy Phillips of the Texas A&M University (TAMU) College of Veterinary Medicine & Biomedical Sciences, had the distinct honor of delivering the Walston Chubb Award Lecture at international research society Sigma Xi’s annual meeting at The Woodlands Waterway Marriott Hotel.
Phillips was invited to deliver the lecture as the recipient of the 2009 Walston Chubb Award for Innovation. Presented by Sigma Xi, the award recognizes Phillips’ 25 years of work on chemical and microbial contaminants of food, particularly aflatoxins. These are toxins produced by certain species of fungi that commonly infect corn and peanuts during drought conditions. Eating food contaminated with aflatoxins results in a disease called aflatoxicosis. Long-term exposure to aflatoxins can cause adverse health effects such as suppression of the immune system and growth retardation.
Phillips’ topic for the lecture, “Down to earth science: Clay-based therapy for mycotoxin exposure in humans and animals,” reflects his major achievement: demonstrating that a naturally occurring, heat-processed clay called NovaSil (NS) can tightly and preferentially bind aflatoxins in the gastrointestinal tract and prevent their toxicity by reducing absorption and bioavailability.
Using molecular and animal models, Phillips and his research group have shown (1) the mechanism of aflatoxin interaction at NS clay surfaces and (2) the safety and efficacy of the clay for use in human trials.
“Individuals who are at major risk of developing aflatoxicosis include the 4.5 billion inhabitants of the ‘hot zone’-the region bound by the latitudes 40 degrees north and south of the equator. Droughts in this region increase fungal infection and consequently aflatoxin production,” explained Phillips. “Guidelines that specify permissible aflatoxin levels in foods are not always strictly followed in the developing countries in this zone.”
One of the most severe outbreaks of alfatoxin poisoning occurred in 2004 in Kenya and was caused by the consumption of meals prepared from aflatoxin-contaminated maize. Aflatoxin levels as high as 8000 parts per billion (ppb) were detected. According to the US Food and Drug Administration, human foods, with the exception of milk, may contain up to 20 ppb aflatoxin. This outbreak caused 125 deaths.
Based on a trial in the United States that confirmed the safety of NS clay and determined the appropriate dose of this clay for use in humans, Phillips and his group carried out a larger clinical trial in humans in Ghana (in the Ejura-Sekyedumase district of the Ashanti region) for testing the efficacy of NS clay. This site was chosen for the study because the people in the region were found to have biomarkers of aflatoxins in their blood and urine, indicating aflatoxin exposure.
The study was carried out for three months. A total of 177 volunteers were randomly assigned to three groups that were given either a high dose, low dose or no dose (the placebo group) of NS clay capsules per day.
The study found that 99 per cent of the participants reported no clay-related side effects. Further, the clay significantly reduced the level of exposure to aflatoxins.
“The findings support the potential application of NS clay for the protection of human populations at high risk for aflatoxicosis,” noted Phillips.
Further studies include optimizing the dosage and delivery methods of NS clay. Also, the safety of NS clay for long-term therapy needs to be determined as well as the effectiveness of the clay when included in human foods.
Phillips’ research has resulted in the establishment of Texas Enterosorbents, Inc., a TAMU-based company, which is involved in commercializing products based on NS clay.
Phillips hopes that like iodine, the clay will be used as an additive in table salt or in groundnut- or maize-based foods. He also aims to make the clay available in the form of “satchels of flavored clay” so that a solution of the powdered clay in water may be taken as enterosorbent therapy in acute cases of aflatoxin exposure. In a future study, he also aims to test the efficacy of the clay when mixed with cornmeal since corn is especially prone to aflatoxin contamination.
Phillips hopes that this “field-practical, sustainable and environmentally benign” approach can help positively impact the lives of the 4.5 billion people in the developing world who are seriously affected by aflatoxicosis.