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GMO Facts and Fictions

With so much interest in the Genetically Modified Organism (GMO) debate lately, I will be writing a series of articles about some of the issues involved. For this first installment, I’d like to clear up some confusion about Bt corn. Some folks mistakenly believe that since Bt spray is acceptable in organic farming, then Bt corn, a GMO product, must also be inherently safe. They are two very different things.

Bt refers to Bacillus thuringiensis, a bacteria which produces a toxin that kills many insects. The toxin destroys the digestive system of insects. It has long been used as a spray to kill caterpillars and other bugs. When sprayed externally on a plant, Bt kills the insects but is not absorbed into the plant. It is easily rinsed off by rain or hand washing. When the crop is harvested, little or no Bt toxin remains. In this form, it is safe for the plants and the humans or animals that ingest them.

With Bt corn (or cotton or soybeans), as manufactured by Monsanto and other chemical companies, the Bt bacteria has been artificially inserted into the genes of the plant, and every cell of the plant produces the Bt toxin. The crop (corn or soy) as well as all other parts of the plant, such as stalks, leaves, and roots, contain Bt toxin. Basically every cell produces Bt toxin throughout the plants life. In this case, the Bt toxin is ingested by humans or animals eating the GMO Bt crop, and large amounts of Bt toxin enter the soil as the tillage remains behind.

In GMO Bt crops, we are consuming the toxin with every bite, and this poison builds up in our bodies and in the fields. There have been several scientific studies showing ill effects in humans and animals from such high quantities of Bt toxin. And as a result of this new widespread use, Bt-resistant strains of bugs have now developed for the first time. Tellingly, Bt corn itself is listed as a pesticide with the Environmental Protection Agency (EPA). In a human study, Bt bacteria were found to have transferred to the normal bacteria in the gut lining in subjects that ate Bt corn, creating a toxin-producing bacteria culture inside human digestive systems. In a future column I will discuss such health studies in more depth.

About 85 percent of the corn in the U.S. food supply is now GMO corn, including Bt Corn, while most other modern nations have not allowed this product in their food. Some countries that allow it require it to be labeled as GMO. Since GMO products are not labeled in the U.S., if one wishes to avoid ingesting Bt toxin, there are two choices. One can avoid corn and corn products entirely, or look for “non-GMO” or organic corn ingredients. GMO products, including Bt corn, cannot be labeled organic.

So there is a world of difference between the safe spray application of Bt to plants compared to the high levels of ingested and environmental Bt toxin that result from genetically modified Bt corn.

If you have specific questions you’d like me to address in this series, please contact me ( or the editor of Big Island Weekly.

Russell Ruderman studied biology at Penn State University, is the founder of Island Naturals Markets and State Senator from Puna and Ka’u districts.