What’s the Point of GE? Case Example of Bt Toxin

I am equal parts enjoying and super creeped out, as I research GE and GMOs. Today’s post draws from the findings presented in the report from the National Academies of Sciences, Engineering, and Medicine called Genetically Engineered Crops: Experiences and Prospects. [1] This report alleges to take a “fresh look” at the peer-reviewed evidence base on GE crops.

What’s the point of GE? [2]

GE allows corporations to introduce genetic traits that can’t be introduced or altered by conventional breeding alone. In other words, GE allows biotech companies to violate natural boundaries in a way that conventional breeding does not. The traits selected include: longer-shelf life, higher vitamin content, and resistance to diseases. For the most part, commercially produced GE crops are designed to resist insects and herbicides that are produced by the same biotech companies peddling the seeds.

The Case Example of Bt Toxin

Specific modified genes from the soil bacterium Bacillus thuringiensis (Bt) are forced into the plant genome. The desired trait is the effect of Bt protein on insects: when an insect eats Bt protein, holes are created in the insect’s digestive system, causing death. The goal is to increase yield by eliminating pests.

Studies indicated that “Bt in maize and cotton from 1996 to 2015 contributed to a reduction in the gap between actual yield and potential yield under circumstances in which targeted pests caused substantial damage to non-GE varieties and synthetic chemicals could not provide practical control.” [3] What a convoluted reporting of the data!

In plain English, researchers drew a causal relationship between Bt and higher yields WHEN the non-GE varieties were substantially damaged by pests due to failure of the pesticides to kill said pests. This sounds like a really specific, reductionist, and virtually meaningless way to determine whether the pest-resistant GE crops actually have higher yields than the conventionally grown crops. And what about a comparison to organically grown crops? Researchers aren’t even gonna go there, I guess. Or have they?

Moreover, the committee listed a number of study disadvantages and possible third variable explanations for the observed differences in yield. The GE and non-GE crops were not isolines; they were genetically dissimilar, and had different characteristics that affect yield. [4] Additionally, differences in insect damage, the farmers who plant Bt versus non-Bt varieties, and other production differences could have explained the observed effect. Bottom line: Bt may have contributed to a higher yield, but maybe not.

Side effects

Statistical evidence indicated that targeted pest populations are greatly reduced in areas where Bt crops are grown, which is beneficial to farmers of Bt and non-Bt varieties. [5] This begs the question: why are farmers still using Bt varieties if the problematic pests have vanished? Moreover, continued use will encourage Bt-resistant pests that defeat the whole purpose.

Thankfully, evidence showed decreased use of synthetic pesticides on Bt crops and non-Bt crops. [6] Some nontargeted pest populations have increased, but not problematically so. Bt resistant insects have been slow to evolve thanks to a US government-mandated regulation.

This strategy requires: [7]

1. Bt plants to contain a high enough amount of Bt protein to “kill insects that have partial genetic resistance to the toxin.”
2. Maintenance of refuges, or the planting of non-Bt crops near the Bt varieties so that some target insects survive and mate with resistant individuals.

Supposedly, the strategy has been successful so far. However, Bt resistant insects have evolved in US and non-US farms where the regulation was not upheld.

All this sounds like troublesome tinkering with nature to control, control, CONTROL. It’s laughable to think that Bt proponents think they are powerful enough to control and outsmart nature. As if!

Keep in mind that Bt is always present in Bt crops. [8] You can’t peel the toxin off. You can’t wash it off with your favorite produce cleanser. It doesn’t go away. Regardless of health findings, I don’t want to eat food that contains a protein that bores holes in digestive systems to kill other living creatures. We’ll get into the health effects of GMOs in a subsequent post.

References:

[1-8] National Academies of Sciences, Engineering, and Medicine. 2016. Genetically Engineered Crops: Experiences and Prospects. Washington, DC: The National Academies Press. doi: 10.17226/23395.

Disclaimer: These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease.