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GMOs Decoded: A Skeptic's View of Genetically Modified Foods

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The debate over genetically modified organisms: health and safety concerns, environmental impact, and scientific opinions.

Since they were introduced to the market in the late 1990s, GMOs (genetically modified organisms, including genetically modified crops), have been subject to a barrage of criticism. Agriculture has welcomed this new technology, but public opposition has been loud and scientific opinion mixed. In GMOs Decoded, Sheldon Krimsky examines the controversies over GMOs—health and safety concerns, environmental issues, the implications for world hunger, and the scientific consensus (or lack of one). He explores the viewpoints of a range of GMO skeptics, from public advocacy groups and nongovernmental organizations to scientists with differing views on risk and environmental impact.

Krimsky explains the differences between traditional plant breeding and “molecular breeding” through genetic engineering (GE); describes early GMO products, including the infamous Flavr Savr tomato; and discusses herbicide-, disease-, and insect-resistant GE plants. He considers the different American and European approaches to risk assessment, dueling scientific interpretations of plant genetics, and the controversy over labeling GMO products. He analyzes a key 2016 report from the National Academies of Sciences on GMO health effects and considers the controversy over biofortified rice (Golden Rice)—which some saw as a humanitarian project and others as an exercise in public relations.
Do GMO crops hold promise or peril? By offering an accessible review of the risks and benefits of GMO crops, and a guide to the controversies over them, Krimsky helps readers judge for themselves.

216 pages, Kindle Edition

Published February 15, 2019

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Sheldon Krimsky

31 books9 followers

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Displaying 1 - 6 of 6 reviews
Profile Image for Ryan.
Author 2 books13 followers
July 8, 2019
A lot to process from this book. Here are some of the most memorable excerpts:

The evidence on the impact of HT seeds on soybean, corn, and cotton yields is mixed...several researchers found no significant difference between the yields of adopters and nonadopters of HT; some found that HT adopters had higher yields, while others found that adopters had lower yields. Yields have a lot to do with multiple factors.

Studies have shown that for HR cotton and soy, herbicide use (measured in lbs per acre) declined slightly in the first years and then increased. The USDA data suggest otherwise: Herbicide use on corn by HT adopters increased from around 1.5 lbs per planted acre in both 2001 and 2005 to more than 2.0 lbs per planted acre in 2010, whereas herbicide use by nonadopters did not change much.

HR crop technology has led to a 239 million kg increase in herbicide use across the three major GE-HR crops, compared to what herbicide use would likely have been in the absence of HR crops.

In the US, it's estimated that plants are subjected to over 50,000 different pathogens (fungi, viruses, bacteria, and nematodes). Any given agricultural region may be faced with between ten and fifteen serious plant diseases. From 1988 to 1990, there was a loss of $300 billion for eight major crops from all sources, and about a third of this loss was due to pathogens.

Even with the extensive application of pesticides, the estimated reductions in the farm-gate value of selected vegetable crops in the US caused by diseases range from 8 to 23%, by insects 4 to 21%, and by weeds 8 to 13%. The average losses caused by diseases, insects, and weeds in Canada are 15.5, 12.5, and 10.5%, respectively.

When a virus-derived transgene is inserted to create a GMO, it can have amino acid sequences that can cause new allergens or cause enhancement of intrinsic allergens. Although this is a hypothetical risk.

The researchers conclude that GM plants that are grown in the same soil for more than three months could change the rhizospheric microbial metabolism; cause negative effects on soil quality, structure, and function; and affect enzyme synthesis and activity, as well as soil processes such as decomposition and mineralization of litter.

It has been estimated that about 67,000 pest species are capable of damaging crops and that about 9,000 of those species consist of insects and mites. Globally, crop losses are at around 37% of what is planted, and about 13% of those losses is attributed to insects.

The toxicity of Bt is receptor-mediated. This means that for any organism to be affected by the Bt toxin the way it is designed to be used against insects, it must have specific receptor sites in the insect's gut to which the protein can bind. It is generally understood that humans and the majority of beneficial insects do not have the Cry toxin receptor sites. Although humans and other animals may not have the receptor sites of Lepidoptera, that does not preclude other means through which Cry toxins may affect them. Any single protein may interact in mnay pathways - not just one. For example, a Cry protein could potentially induce allergenicity in mammals but not have this effect in insects.

The majority of the laboratory studies that were performed to test the infectivity and toxicity of Bt commercial products have indicated that these products are safe. Yet, such studies are not enough proof that these products are innocuous to mammalian cells or vertebrate organisms.

The overuse of Bt is likely to undercut its selective use in organic farms.

The genome in which the foreign gene is placed acts more like an ecosystem than a Lego system. That means that genes interact with one another. If a gene is introduced into a plant genome, some other gene (or genes) already in the host plant could be affected. That preexisting gene might code for a protein that is a nutrient, a toxin, or an enzyme, or it might perform a regulatory function.

David Schubert, a geneticist and professor at the Salk Institute, cites 3 important conditions underlying the movement of genes across organisms:
-The introduction of the same gene into two different types of cells can produce two very different protein molecules.
-The introduction of any gene, whether from a different or the same species, usually can change overall gene expression and therefor the phenotype of the recipient cell.
-Enzymatic pathways that are introduced to synthesize small molecules such as vitamins, could interact with endogenous pathways to produce novel molecules. This is particularly relevant to creating transgenic nutritional changes in plants.

Innate was designed with lower amounts of the amino acid asparagine, which turns into acrylamide during frying.

The panel's overall assessment of GMO yields is consistent with the scientific studies that show that GMO yield increases were idiosyncratic, circumstantial, and not systematic.

Regarding the 2016 National Academies Study, a report found that 6 out of the 20 panel members had financial interests in GE crops, including patents and corporate research grants.

There is no clear consensus that GMOs are inherently better or worse than non-GMO varieties in terms of yield. You must consider each region, practice, climate, pest density, pesticide use, farm practice, etc.

It is not feasible to ask whether a particular system, industry or technology is 'sustainable' or 'unsustainable,' but useful to consider whether it is associated with a tendency towards or away from sustainability.
This entire review has been hidden because of spoilers.
Profile Image for Jim B.
36 reviews
February 4, 2023
One of my biggest pet peeves is when people use the word “skeptic” incorrectly. A true skeptic reserves
judgement on a subject until there is enough good evidence to accept or reject it. If someone doesn’t
believe in climate change they are a climate change denier, not a climate change skeptic. Similarly,
someone who is anti-GMO, such as this author, might best be referred to as a GMO contrarian, since
they reject the scientific consensus on the topic. Sheldon Krimsky is NOT a GMO skeptic, despite what
the subtitle says.

The book starts off ok, if a little dry. But by the end you get the feeling that Mr. Krimsky is a regular
Goop shopper.

Skip this book. For a much more readable and scientific text on GMOs get “Seeds of Science” by Mark Lynas.
Profile Image for Ietrio.
6,949 reviews24 followers
July 12, 2019
The word Skeptic is misused. The right word is primitivist. And although the discourse itself has changed to integrate the New Age scientism, it is the same desperate attempt to rationalize a hysterical fear of unknown. The only use for this book would be to give a speculative glimpse into the minds of the illiterate peasants of Europe dying of hunger, yet refusing the potato. Centuries later the potato is fine, but beware of the "new" GMO potato.

Don't get me wrong, the fear is legitimate. The same way cats on YouTube get scared of a cucumber, Krimsky has a right to wet the bed while waiting to be eaten by the GMO monster hiding under the bed. The problem is the ignorant with pitchforks petitioning the local dignitary for a new GMO czar to exorcise the evil genes out of the peaceful plants.
Profile Image for Joel Beebe.
85 reviews2 followers
July 10, 2022
I think this was a decent overview of GMOs, although the technology is marked by a significant lack of data on whether it's safe or not. Like, a lot of the conclusions Krimsky comes to is just, "we don't know yet." The lack of data is further muddled by Monsanto science and other conflicts of interest that would have a motive to not find anything wrong with them. This science is marked by phrases that don't mean anything like the concept of "substantial equivalence" between GMO and Non-GMO plants. The science isn't exactly transparent or even good science to begin with.

That kind of goes to my main issue with GMOs, the system of private property and patents associated with it. There's a lot of money here, any way you look at it, without necessarily providing many benefits to our food systems. This muddles potential benefits from GMOs by opposition to GMOs being all-encompassing rather than nuanced, which makes sense given the whole oligopoly and economic colonialism thing. But at the same time, if there's something that could help millions of children, then it should help millions of children.

As always, the answer is abolishing private property and scientific transparency. I don't see a future without GMOs given the post-scarcity world they could help deliver, along with other things to say the least. But obviously, safety and public trust are essential to this.
3 reviews
February 15, 2024
Scholarly approach. Oustanding list of questions that need to be answered. Balanced analysis of GMO and taditional breeding. Recognizes the need for better scientific testing and the power of public skepticism. As of 2019 when the book was published, regulations did not protect organic farmers from cross-contamination. Europe has done a much better job of protecting small farmers and consumers. Many US studies and advisory board reports have revealed conflict of interest bias toward GMOs.
Profile Image for Maisie.
109 reviews4 followers
June 24, 2019
3.5

I went into this book with the understanding that the health effects of GMOs are not well understood and more research is needed. That GMOs are a complex issue and really more research is needed to understand all the ramifications. That even with the biological factors aside, they create litigation problems for farmers who don’t want to grow GMOs but are sued because someone else’s crop drifted and contaminated theirs. I finished the book with the same understanding. Not that this book wasn’t interesting—I learned more about the history of GMOs and the exact scientific process and arguments for/against their safety. But everything is so theoretical, for anyone troubled by today’s issues and wanting answers now, it does not deliver.
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