Do pesticides reduce our total exposure to food borne toxicants?

In addition to the long history of disease and death from natural toxicants in plants, there is a growing literature about the abundant levels and varieties of natural toxicants in our foods. These natural chemicals cause mutagenicity, carcinogenicity, teratogenicity, neurotoxicity and visceral organ toxicity in routine laboratory tests. While many of these chemicals occur at rather fixed levels in foods, there is evidence that a large number of natural toxicants increase or decrease with levels of plant stress. When plants are stressed from infection or predation, they characteristically respond with a rapid increase in defensive chemicals. Because increases in natural toxicants are stress mediated, the prevention of infection and predation can reduce the levels of the natural toxicants in our food supply. In addition, fungal infections induce a chemical response from the plant, and also excrete their own array of toxins, sometimes at high levels. Crop protection chemicals are used to reduce plant stress, but there is no program today to balance the risk from crop protection chemicals (which are extensively tested and heavily regulated) against the possible benefit of decreased risk from natural plant and fungal toxicants (which are only sporadically tested and are largely unregulated). Because crop protection chemicals are logically linked to inhibition of the expression of natural toxicants, there may be considerable food safety benefits from an approach to pesticide risk management that evaluates the risk versus risk equation. On the other hand, inattention to the issue of suppression of natural toxicants may lead to an unintended increase in our exposure to this wide array of naturally occurring chemicals.