3 ms·

I can't think of a mechanism for GM crops causing allergies. How would this work?

TimTheTinker 4y ago
Genetic modification often produces altered proteins. These protein signatures do not match human T-cell allowlists, causing immune response. Even if the modification is a simple addition between adjacent start and stop codons, that kind of modification could alter meta encodings that control other aspects of cell regulation, including (potentially) gene expression -- which would cause proteins that are coded for but that normally aren't present to become present in crops. Even one newly expressed protein (that is normally not ever expressed) could trigger immune response.
- sooheon 4y ago
  You know genetic modifications occur literally all of the time in everything we eat, right?
  - TimTheTinker 4y ago
    Yes, of course. But there's a difference between multiple short sequences being added/deleted/modified and entire new proteins that add new capabilities being inserted or swapped. These artificial edits introduce large step functions in the overall mutation rate. Normally, parallel evolution of people and crops allows humans enough time to adapt to natural mutations. Note selective breeding doesn't increase the underlying mutation rate - that's the number that I'm concerned we've manipulated beyond acceptable bounds.
- colechristensen 4y ago
  Genetic modification isn’t a bull in a china shop. The glyphosphate resistance gene replaces the shape for one enzyme. You don’t have a whitelist for every substance in every lifeform you eat, the number of things out there is mindbogglingly enormous. It would be very simple to test the human reaction to this new enzyme, i bet it’s been done but i don’t want to search for it.
- collegeburner 4y ago
  then why are nut allergies the most common when there are no GMO nuts? or shellfish when we don't have GMO shellfish? why do whites have higher rates of childhood allergies (6.6%) but blacks are now rising the fastest? none of this really seems to fit with a GMO hypothesis.
  - TimTheTinker 4y ago
    If you're looking for a single hypothesis, then yeah those numbers would throw doubt on the GMO as cause hypothesis.
dekhn 4y ago
THere's a classic paper where somebody cloned brazil nut genes into soybeans. Unfortunately, the genes they cloned were the ones that code for protein allergens... making the resulting soybeans cause brazil nut like allergic response. I don't think this work was ever followed up, or repeated, but it's an entirely plausible mechanism by which genetic modification could cause allergies. (are you a biologist? this stuff is pretty obvious to biologists)
- HPsquared 4y ago
  I'm a total layman when it comes to biology. Chemical engineer by training, never got into the biotechnology side though.
  - dekhn 4y ago
    Actually chemical engineer is a good foundation. You should probably be able to read this paper: https://www.nejm.org/doi/10.1056/NEJM199603143341103?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200www.ncbi.nlm.nih.gov https://www.nejm.org/doi/10.1056/NEJM199603143341103?url_ver... The goal in this case was to improve soybean amino acid content (soybean is a major world crop, with Brazil being one of the top suppliers). Pioneer- one of the major seed companies- created a transgenic (moving a whole gene from one organism to another) soybean with a gene from Brazil nuts. That gene turned out to be the one that produces the protein in Brazil nuts which causes an allergic reaction and the soybeans actually seem to cause a reaction in people who consume them (I'm glossing over a bunch of technical details in the paper). It's not hard to image, with an existence proof like this, that there are many ways that GM crops could increase the risk to consumers. Any biologist I've trained with who understands transgenics and immune response would immediately note that this was a fairly obvious potential risk/outcome provided the source gene's properties had been identified first.
glyphosate 4y ago
1. Plants defend themselves from predators (i.e. animals, humans, insects) via chemical warfare. These chemicals can and do disrupt the gut of the predator to dissuade them from consuming the plant. At least in humans, 70-80% of immune cells are contained in the gut. Many genetically modified plants are engineered to produce more of these gut disrupting chemical defense compounds to be more resistant to predators. 2. A study by the CDC estimates that 80% of Americans have glyphosate in their urine. Glyphosate is an antibiotic proven to be disrupting to gut bacteria. Crops are being genetically engineered to allow for more and more glyphosate exposure because the weeds are growing increasingly resistant to it, requiring even more glyphosate - which in turn runs off into our water supply. It's a positive feedback loop as nature abhors monoculture (less diversity = less evolutionary resiliency), and seeks to restore balance and diversity with pests, weeds, viruses, etc. Monocrop agriculture is fundamentally unsustainable

Genetic modification often produces altered proteins. These protein signatures do not match human T-cell allowlists, causing immune response. Even if the modification is a simple addition between adjacent start and stop codons, that kind of modification could alter meta encodings that control other aspects of cell regulation, including (potentially) gene expression -- which would cause proteins that are coded for but that normally aren't present to become present in crops. Even one newly expressed protein (that is normally not ever expressed) could trigger immune response.

sooheon 4y ago
You know genetic modifications occur literally all of the time in everything we eat, right?
- TimTheTinker 4y ago
  Yes, of course. But there's a difference between multiple short sequences being added/deleted/modified and entire new proteins that add new capabilities being inserted or swapped. These artificial edits introduce large step functions in the overall mutation rate. Normally, parallel evolution of people and crops allows humans enough time to adapt to natural mutations. Note selective breeding doesn't increase the underlying mutation rate - that's the number that I'm concerned we've manipulated beyond acceptable bounds.
colechristensen 4y ago
Genetic modification isn’t a bull in a china shop. The glyphosphate resistance gene replaces the shape for one enzyme. You don’t have a whitelist for every substance in every lifeform you eat, the number of things out there is mindbogglingly enormous. It would be very simple to test the human reaction to this new enzyme, i bet it’s been done but i don’t want to search for it.
collegeburner 4y ago
then why are nut allergies the most common when there are no GMO nuts? or shellfish when we don't have GMO shellfish? why do whites have higher rates of childhood allergies (6.6%) but blacks are now rising the fastest? none of this really seems to fit with a GMO hypothesis.
- TimTheTinker 4y ago
  If you're looking for a single hypothesis, then yeah those numbers would throw doubt on the GMO as cause hypothesis.

dekhn 4y ago

THere's a classic paper where somebody cloned brazil nut genes into soybeans. Unfortunately, the genes they cloned were the ones that code for protein allergens... making the resulting soybeans cause brazil nut like allergic response. I don't think this work was ever followed up, or repeated, but it's an entirely plausible mechanism by which genetic modification could cause allergies. (are you a biologist? this stuff is pretty obvious to biologists)

HPsquared 4y ago
I'm a total layman when it comes to biology. Chemical engineer by training, never got into the biotechnology side though.
- dekhn 4y ago
  Actually chemical engineer is a good foundation. You should probably be able to read this paper: https://www.nejm.org/doi/10.1056/NEJM199603143341103?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200www.ncbi.nlm.nih.gov https://www.nejm.org/doi/10.1056/NEJM199603143341103?url_ver... The goal in this case was to improve soybean amino acid content (soybean is a major world crop, with Brazil being one of the top suppliers). Pioneer- one of the major seed companies- created a transgenic (moving a whole gene from one organism to another) soybean with a gene from Brazil nuts. That gene turned out to be the one that produces the protein in Brazil nuts which causes an allergic reaction and the soybeans actually seem to cause a reaction in people who consume them (I'm glossing over a bunch of technical details in the paper). It's not hard to image, with an existence proof like this, that there are many ways that GM crops could increase the risk to consumers. Any biologist I've trained with who understands transgenics and immune response would immediately note that this was a fairly obvious potential risk/outcome provided the source gene's properties had been identified first.

glyphosate 4y ago

1. Plants defend themselves from predators (i.e. animals, humans, insects) via chemical warfare. These chemicals can and do disrupt the gut of the predator to dissuade them from consuming the plant. At least in humans, 70-80% of immune cells are contained in the gut. Many genetically modified plants are engineered to produce more of these gut disrupting chemical defense compounds to be more resistant to predators. 2. A study by the CDC estimates that 80% of Americans have glyphosate in their urine. Glyphosate is an antibiotic proven to be disrupting to gut bacteria. Crops are being genetically engineered to allow for more and more glyphosate exposure because the weeds are growing increasingly resistant to it, requiring even more glyphosate - which in turn runs off into our water supply. It's a positive feedback loop as nature abhors monoculture (less diversity = less evolutionary resiliency), and seeks to restore balance and diversity with pests, weeds, viruses, etc. Monocrop agriculture is fundamentally unsustainable