My main question is can we map what a fruit is made of? For instance apples are made of 0.0002% of protein X, 0.00001 of protein Y, 0.001% of amino acid Z... etc...

If we can, then my next question would be why do people fear eating GMOs? I understand the argument that if you introduce a new compound to your body you don't know its effect on you, but if for instance you insert a new gene into the plant where it is resistant to drought- can we not simply analyze its product and if its composition haven't changed than everything is alright?

Thank you very much!

  • 1
    $\begingroup$ I think this is mostly a matter of not understanding how the technology works. And also thanks to the fear mongering of some activist groups. $\endgroup$
    – Chris
    Feb 24 '15 at 10:39
  • $\begingroup$ I guess only time can prove if those fears are true. There is too much which we don't still understand to say with certainity that inserting a segment of gene will not have any deteorating effect $\endgroup$
    – One Face
    Feb 24 '15 at 10:49
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    $\begingroup$ Note that 'fear' of GMOs often have two different angles - human health effects and environmental/biodiversity concerns - which are conflated in this question. $\endgroup$ Feb 24 '15 at 11:06
  • $\begingroup$ thank you guys, my question was however about the health aspects of eating plants where the edible part haven't been changed and is 100% identical to the original source. $\endgroup$
    – curiou
    Feb 24 '15 at 15:38
  • $\begingroup$ Why do some people fear vaccines, nuclear power, radiation from cell phones, or any of a thousand other scare-mongered things? Usually it's the result of some very cynical people preying on mass ignorance for their own political and/or financial advantage. $\endgroup$
    – jamesqf
    Feb 24 '15 at 18:04

People are not always rational when it comes to what they eat, especially when the compounds that make up the food have long, arcane-sounding names.

It is indeed possible to analyse the amino acid composition of a food substance. However, this has no bearing whatsoever on the safety of the food product.

For example, the following are two truncated protein sequences. One of them is a fragment constituent of cobra venom, the other is a fragment of harmless DNA polymerase. Without looking up or otherwise referring to the PDB IDs, it is not obvious which is which, even to an experienced molecular biologist.



Furthermore, even if scientists can prove beyond reasonable doubt that the two products are chemically identical, people will still irrationally purchase them. A clear example is the different prices commanded by "natural" versus "artificial" flavourings, as seen in this Scientific American article.

Consumers pay a lot for natural flavorings. But these are in fact no better in quality, nor are they safer, than their cost-effective artificial counterparts.

  • $\begingroup$ Thank you very much for the reply. First of all I must note that I'm a complete layman (who skimmed over Wikipedia about SCOP and protein structures) so I'm probably missing something obvious and my question is stupid... Those two PDB IDs that you presented seems different, so it is more of a case that is hard to diagnose their function rather than say that they are a 1 to 1 copy. Have I understood you correctly? As for the article, well, some might say that it is not that health concious consumers are wrong about how bad artificial flavours are, it is that $\endgroup$
    – curiou
    Feb 24 '15 at 15:28
  • $\begingroup$ it is that they are wrong about the meaning of 'natural flavours' (which raise the association of fruit juices/extracts). Also, I obviously know very little, but are those flavours the same? Even according to this article ----"So is there truly a difference between natural and artificial flavorings? Yes. Artificial flavorings are simpler in composition and potentially safer because only safety-tested components are utilized." "There is little substantive difference in the chemical compositions of natural and artificial flavorings."---- maybe it's my $\endgroup$
    – curiou
    Feb 24 '15 at 15:30
  • $\begingroup$ maybe it's my english but it seems like he's saying that a minute difference is still there (even if the author see this as an indictment toward the natural substances). The thing is, you are right about peoples irrationality, but in this case the argument that such GMO food (lets say the transgeneic variety) introduces a new set of variables to the human organism which we can't trust unless rigorously tested for many many years (a generation or two if we want to see long term effects)- seems quite rational. If someone were to $\endgroup$
    – curiou
    Feb 24 '15 at 15:30
  • $\begingroup$ If someone were to sequence every single molecule in that new apple/tomato and show that the new product is a 100% clone of its counterpart then maybe it won't affect everyone, but at least the pro GMO will be on an unshakable ground... (Actually I just googled natural 'colorants' and it seems that some green sites are against them due to the same scientific reason like in your article- so, the trickling of knowledge is present). If it's possible is there a reason why it is not being done? (or is it simply a calculation of cost/expected results in public opinion?) $\endgroup$
    – curiou
    Feb 24 '15 at 15:30
  • $\begingroup$ Dang it, what happened to my paragraph division? sorry if my response is too long. $\endgroup$
    – curiou
    Feb 24 '15 at 15:31

I agree with March Ho in general: people are not rational about food.

That said there are two fairly different kinds of GMO, with different implications on the fears to have about them.

1) GMO embedding genes from the same species

These are not supposed to be any different from plants obtained using classical breeding techniques. The process in brief is for example: you see a wheat individual with short stems, an other with big grains. You want both. In classical selection you have to breed the two, select the descendants, breed again, select etc... until all descendants have both characters. Using GMO you can simply pick the gene you want and put it in the strain of your liking. It is much, much faster and the changes in the genome are much less than what you get by breeding two strains.

2) GMO embedding genes from other species

This can be more problematic as the gene you brought in could be from an organism nobody did ever eat, such as the Bt toxin in MON 810, hence the questions about toxicity. It doesn't mean it's toxic and the controls are very stringent about that but I can understand better why such GMO should be carefully checked.

3) The false problem of GMOs and environment

A Last problem is the indirect effect of the GMO, for example, if it's designed to be herbicide tolerant it might allow more herbicide to be poured on the plants and hence cause more herbicide residuals to be in the food, or in the environment, people then not liking GMO for environmental related reasons. But that should be addressed by checks on herbicides in food or in the environment, not by banning GMOs!

That said, GMOs have been around now for 20 years and people against GMO have a very hard time showing any kind of negative effects (see links posted previously), and some studies "proving" the toxicity have been shown to be statistically weak, not to say fraudulent.


There is no good reason to reject type 1) GMOs based on food safety and very little reasons to reject type 2) GMOs. I would personally push hard for a general adoption of GMOs bearing genes from the same species or other edible plants. It would already make a lot of things easier!

  • $\begingroup$ Thank you for the expounding, I must ask though about type 1, do we know about the concert and interplay of all the genes? Can we predict all the cascading effects in all the plants that we change? Do we know that all those genetic alterations that occur when you use classical breeding are not actually necessary in order for the edible end product to convey some yet unknwn characteristics (certain protein and etc)? thx. $\endgroup$
    – curiou
    Feb 24 '15 at 15:32
  • $\begingroup$ Answers to questions in your comment in order: No; No, but this is the case for normally bred organisms too; the organism modified already conveys those characteristics and there's no a priori reason to expect any change in that. $\endgroup$
    – Devon Ryan
    Feb 24 '15 at 17:37
  • $\begingroup$ Yes, but if we don't actually know everything about the chain reactions that happen when we artificially introduce a new gene, then how can we tell that no characteristic indeed will be affected? Like the famous Rumsfeld quote about unknown unknowns, the only way we can be sure that our product is "as nature intended" is if the artificial result will be 100% identical to the classically bred (which we can't compare unless we actually make both). no? $\endgroup$
    – curiou
    Feb 24 '15 at 21:26
  • $\begingroup$ Do you consider a plant that has a genome recomposed from two different species+ duplicated to be "as nature intended". That's the wheat you eat everyday. Obtained by very artificial selection several thousand years ago. Was there a risk to taste that incredible mix. Probably but I'm fairly happy they tried. All new varieties are extensively tested but I see no reason why type 1 GMO should be prohibited and not just extensively tested. $\endgroup$
    – cmbarbu
    Feb 24 '15 at 21:44
  • $\begingroup$ Perhaps I should have not used the term "as nature intended" since it might bring some association with other ideas... However, when you say "two species" you are not exactly being accurate and you give a wrong impression as well. If they can cross polinate then they belong to the same family which in genomic terms is (or might be) quite important. Furthermore, like you said, they started doing it thousand of years ago. The first aspect to this is that there are plenty examples where human behaviour changed our physical evolution (in relatively short time), if we'll all start $\endgroup$
    – curiou
    Feb 25 '15 at 13:21

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