Overview

We are in a unique position to test a novel, clay-based technology that could achieve major advances in human health for populations exposed to high levels of aflatoxins in the diet. Aflatoxins are harmful by-products of mold growth and (though invisible to the naked eye), are potentially fatal. The aflatoxin problem is longstanding and seemingly inextricable. Aspergillus flavus and parasiticus (the molds primarily responsible for the elaboration of the aflatoxins) are widespread and especially a problem during extended periods of drought. Moreover, aflatoxins are heat stable and survive a variety of food processing procedures, and they occur as “unavoidable” contaminants of many foods (particularly maize and peanut). Also animals can secrete carcinogenic metabolites of aflatoxin in their milk. Consequently, a variety of dairy products (including cheese and ice cream) can be contaminated with these chemicals. Aflatoxin B1 (the most toxic of the aflatoxins) has been strongly implicated as a cause of disease and death in man. Following ingestion, it damages the liver, is a potent carcinogen, and acts to synergize the development of hepatomas when other cancer causing agents (such as hepatitis B virus) are present (Phillips et al., 1994,1995). There is substantial evidence that low level exposure to aflatoxin may cause suppression of the immune system and increased susceptibility to disease (Peska and Bondy, 1994). Aflatoxin is also excreted in mother’s milk and may contribute to failures in pregnancy. It also increases the morbidity of children with kwashiorkor in developing countries (Adhikari, 1994). Clearly, the young of all species are very sensitive to aflatoxin. What is not clear is how these actions of aflatoxin contribute to commonly perceived human health problems and child survival in Africa and other developing countries. In light of these problems with aflatoxin, it is clear that effective strategies for the remediation of aflatoxin-contaminated food in developing countries are critical needs.

A safe and practical (clay-based) approach is outlined in this proposal. Our strategies will be based upon the dietary inclusion of inexpensive clay minerals that can act as aflatoxin enterosorbents to tightly sequester and inactivate these poisons in the gastrointestinal tract. As a general rule in toxicology, “the dose makes the poison” and the toxic and carcinogenic effects of aflatoxin are clearly “dose” dependent. We anticipate that NovaSil (HSCAS clay), when included in the diet of humans, will act to block, or significantly diminish exposure to aflatoxins and prevent the adverse effects of these poisons in humans consuming aflatoxin-tainted grains.

We believe that it is appropriate to invest in a project to investigate the consequences of introducing into the diets of a population the clay-based technology described above. This project would have the overall goals of determining if HSCAS clay is effective, acceptable and pays the expected dividends to health and development. An understanding of these outcomes will expedite the optimization, transfer and application of this important technology to other developing countries and the USA. It is anticipated that the collaborative research outlined in this proposal will provide creative, culturally acceptable, economically viable, environmentally benign and sustainable strategies that will benefit human health and well-being around the world.

In this project, our objectives and specific aims are defined within three major phases of study. Phase I and Phase II research will be accomplished at Texas A&M University in College Station and at the Noguchi Memorial Institute for Medical Research in Ghana. In Phase III studies, we propose to determine the feasibility of HSCAS clay as an enterosorbent for aflatoxins via human dietary interventions in Ghana.