Has any harm been proven to be caused by GMO foods?

I hear a lot of woo and panic about them but not a lot of real science. Also, I understand that selective breeding is genetic modification, and no horror stories have ever been written about that.

Selective breeding is modification in the sense that certain pre-existing genes are being reinforced, but new genes are not introducted into the genome of the organism and only occur through mutation or lateral transfer.

Vegetables and animals which are identified as genetically modified organisms (GMOs), however, have foriegn genes inserted into the genome to obtain desireable properties; typically, to instill resistance to pesticides (i.e. Roundup), provide antibiotic resistance to bacteria, enhance growth rates of edible tissue or higher nutrient yield, provide a longer shelf life after harvest, or make the organism more visually appealing. Some suggestion that pharmaceuticals could be distributed via GMOs has been discussed, though I’m not aware of any serious proposals to do so.

Proponents of GMO foods point out (quite rightly) that these modifications provide desireable benefits, particulalry in enhanced nutrient yields, which could benefit consumers at large and especially people living at a sustinence level (e.g. the high Vitaman A “Golden Rice”), and that their native resistance requires less application of pesticides. On the other hand, it should be pointed out that a lot of the public advocacy groups are heavily supported by agricultural biotechnology and agrichemical companies like Monsanto and Archer Daniels Midland, who have a long history of manipulating the definitions of nutrition to suit their products, price fixing the constitutants of processed foods and feedstock, and using claims of intellectual property rights to sue the living daylights out of smaller competitors in order to maximize profits. These companies are about as trustworthy and impartial when it comes to health and nutrition claims as tobacco companies are about their products, and in fact, have often adopted the same tactics and hired some of the same legal firms to represent them.

Opponents of GMO foods argue that the potential risks may be unrealized until years or decades after the foods are on the market, and the “Shake-n-Bake” approach that is current genetic engineering lacks rigor in assessing potential harms, especially when it comes to allergens or long term toxicity of untested gene modifications. To date, there are (as far as I’m aware) no widely accepted studies at indicate harms uniquely associated with any GMO food product. However, the somewhat tortured qualifiers on that statement are because of the difficulty in really associating harms to a particular food that is one of many substances that a wide population may consume, especially if those harms are chronic rather than prompt in nature, e.g. reductions in fertility, higher incidence of cancers, deficencies in micronutrient uptake, retardation or acceleration of development, et cetera. It is difficult enough just to baseline such factors much less identify deviations from the baseline as associated with a particular product or source.

And thus lies the problem; what we term as “genetic engineering” is really more like “genetic tinkering”. Despite advances in gene sequencing and modeling, our ability to predict the outcome of any particular modification or insertion of a novel gene into an existing genome is basically nil. We insert a gene for, say, more robust tissue into a tomato for longer shelf life, but we don’t know if it will incidentially create or increase an enzyme that will act as a hormone stimulus or retardant. The odds that it will do something seriously detrimental are slim, but at least with conventional selective breeding practices we can be almost certain that no radical new compounds will arise; we do not have the same assurance from genetically modified organisms, and in fact, it is almost guaranteed that such manipulation will at least occasionally produce unexpected bioreactive compounds.

The worst part of this, however, is that the US Food and Drug Administration–the regulatory agency responsible for vetting foods, pharmaceuticals, and many other products sold to the public for internal consumption or for direct application on skin–really has no process whatsoever for evaluating the safety of genetically modified organisms, nor do they have the kind of expertise in genetic modification to do so. For that mater, neither does the European Food Safty Authority, although they have been working on this issue for significnatly longer and without the legislative handicaps that have prevented the FDA from getting more involved in evaluating GMOs. Even if there were, there is no way to “prove” that GMO-based foods are not in some way harmful, any more than even exhaustive pharmaceutical studies can “prove” that a drug does not produce harms if taken long term.

The worst fears of GMO opponents are doubtless overblown, and there is certainly an industry behind so-called organic foods which would seek to brand GMOs as being innately harmful or at least suspect while selling supposed ‘natural’ foods (virtually none of which are actually in the form that they evolved via natural selection) at a high premium that is unaffordable to most. On the other hand, given the perfidy of agribusiness/biotech companies to reap a profit on their extensive investments into genetically modified organisms, it is without question that the health and safety of hte public is not their top priority. Ultimately, food grown “organically” is not going to support ten billion people, and as genetic modification becomes more sophisticated it will extend to not just food and pharmceuticals but likely to nearly every aspect of manufacturing that uses organic materials. Spastic, knee-jerk fear of GMOs is like being terrified of automobiles circa 1900; you either grow out of it, or you’re going to be socially and technically isolated. But that doesn’t mean that there aren’t real potential harms to be considered, and a need for some kind of indepenent expert review that protects the public interest.


Quick answer: No.

Unless you forage for wild plants nothing, and I mean nothing, that you eat has NOT been genetically modified in some way. You think modern wheat, corn, chickens, tomatoes exist in nature? They do not.


Except opponents of GMO oddly have no problems with the real “Shake-n-Bake” process of mutagenic breeding, under which over 3200 species varietals have been released, all of them with absolutely no assessment of potential harms whatsoever and many of them commonly sold as organic foods.

From an objective perspective, mutagenic breeding is vastly more irresponsible than GM since the effects are essentially random with no ability to target. Yet, because it’s not the boogeyman du jour, it slides under the radar with nobody calling for rigor even 1/10th as stringent as what is called for from GM foods.

Don’t forget that traditional cross-breeding is essentially random, and can create animals and plants with bizarre phenotypes as the end result.

People who lionize organic food are putting quite a lot of trust in a system where individual steps are pretty much random, such that it’s very difficult to use previous successes as evidence the practice is not harmful.

Exception: wild caught fish and other seafood. The difference is that GMO foods have been done by an intentional, not random, procedure. While it is true that GMOs usually use genes from other organisms, that is hardly unique. Certain viruses can move genes from one organism to another.

yup. :smiley:

You mean herbicide, surely?

Herbicides are a kind of pesticide.

There’s a sprinkling of disreputable and debunked science (Seralini’s offerings, the notorious “pig inflammation” study for example) but zero solid science showing any harm after decades of consuming genetically modified foods. On the other hand there are 2000+ studies (many of them independent i.e. non-industry financed) validating GMO safety, and a recent comprehensive study on GM feed showing no health outcome differences between animals fed GM and non-GM feed.

We ran into the same “you can’t trust the food industry” argument in the recent GD thread on GMO labeling, and I’ll note again that this argument 1) ignores the voluminous non-industry funded research demonstrating GMO usefulness and safety, and 2) this tactic is the same one used by antivaxers to slam vaccines (“you can’t trust Big Pharma!”).

It is truly a bankrupt strategy.

As for “genetic tinkering”, this description is far more aptly applied to “conventional” plant breeding, in which there is large-scale unplanned gene alteration/movement and no requirement for testing whatsoever. There have been rare but notable instances of sickness due to new conventional food plant varieties, even organic ones (i.e. the New Zealand “killer zucchini” and the Lenape potato), but no such instances yet involving GM produce. It would not be a total shock if, despite precise gene splicing and testing, a GM vegetable one day was shown to, say, cause an allergic reaction in some people. But the odds of that happening seem to be considerably less than for “conventionally” developed produce.*

*not to mention that hypo- and non-allergenic GM versions of vegetables/grains
promise to enrich diets for many people who currently cannot safely eat certain things.

It’s not necessary to believe anti-vax hysteria to also believe that pharmaceutical companies generally act in their own and not the public interest, and one need not even be an organic true believer to think the GMOs have negative side effects, even if indirectly. Organic farmers trying to plant next to fields of Roundup-resistant plants have their crops die from overspray. GMO feed corn ends up in human products like tortillas. And “sometimes natural/organic cultivars have negative side effects!” =/= GMOs are safe.

I’m not against them per se, but as Stranger points out it is difficult to evaluate their effects, there are no effective monitoring agencies or testing programs, and the companies selling them have a vested interest in asserting their safety.

There’s a long history of large companies selling harmful products when there isn’t effective oversight. Big Ag may be no worse than any other industry, but there’s no reason to think it’s any better.

Which misses the point entirely. Pointing to bad acts by pharmaceutical companies does not invalidate the admirable health and safety record of vaccines, which have been evaluated in many, many studies by researchers not paid by the drug industry. Similarly, GMO testing and evaluation has been performed by many independent researchers reaching similar safety conclusions; thus it is a less than cogent and honest argument to say that Monsanto has done shady things, therefore genetic modification should be viewed with suspicion.

Similarly missing the point entirely. See above.

I would argue that the safety record to date helps considerably in both evaluating “their effects” and the success of monitoring by the FDA and other agencies. Improvements in testing may be deemed necessary; on the other hand interminable wrangles aimed at blocking useful and even vital GM crops like golden rice on ideologic rather than scientific grounds are not helpful.

*anti-GMOers are big on hyping alleged dangers of crops like GM corn; they are much quieter on the subject of (for example) GM cotton and GM brinjal, which have been enormously beneficial for Third World farmers and consumers which as a result have been exposed to far fewer pesticides.

I love threads about one topic that inadvertently educate on another.

I just learned that “brinjal” is the South African term for “eggplant” (or “aubergine” depending on who’s reading this).

Brinjal is also the term commonly used in India.

That’s what I was going to say… treating seeds and seedlings with high doses of radiation to essentially see what happens seems far more scattershot and insane than deliberately inserting a specific gene for a specific purpose into a plant.

I’m not saying that GMO foods are inherently safe or anything like that, but rather that the process is very deliberate, directed and scientific, unlike conventional or mutation breeding. This is really fear of the unknown; people get freaked out that someone inserts a fish gene into a plant to make it produce natural antifreeze because it’s not “natural”, but don’t bat an eye when a potato variety turns out poisonous because that’s the way the natural breeding shook out, because that’s “natural”. And it’s likely that the GMO product would have more testing and oversight due to the way it’s generated, while the natural plant literally made into the food production pipeline and was only discovered after people were sick.

Anti-GMO and the whole organic food movement are no more than latter-day Luddite thinking. Technology can be bad, so therefore it must be bad, and “natural” stuff is always good, even if you have to use 3x the amount of “natural” pesticides or fertilizers that end up being more polluting and toxic in the overall analysis. But one’s from plant roots, and the other is 2-(dimethoxyphosphinothioylthio) butanedioic acid diethyl ester, so the first must be safer, right?

Wrong. Rotenone is far worse than Malathion, but Rotenone is considered “organic” and was used for decades on organic produce.

…and now that’s two things I learned today. Thanks! :smiley:

GMO tryptophan was a great hit in the early 90’s:
US Tryptophan Disaster – GM Bacteria
The Showa Denko Tryptophan disaster reevaluated

Made it impossible to find Tryptophan in any of the supplement stores for several years, while the feds, the scientists and the companies got things straightened out.
Bottom line cause: people got sloppy.

Now I can buy Typtophan again and have wild dreams.

GMO products have their uses. For example, I make tortillas with roundup ready corn, but just because something is GMO does not mean that someone has run all the toxicity tests on the stuff that should be run before releasing it for human consumption. As usual, the profit motive is a strong motive.

We did indeed, and that wasn’t the only argument that was made, although it’s remarkable the degree to which self-serving pro-business lobbyists and charlatans are lined up on the pro-GMO side – Heartland, AEI, CEI, practically the whole food and agriculture chemical industry and their lobbyists. I just recently discovered that Martin Durkin, the producer of the reprehensible documentary The Great Global Warming Swindle, had previously done an equally shoddy documentary promoting GMO.

I understand your point. This doesn’t prove that GMOs are not safe, and I’ve already agreed that all the evidence is that at present, they are perfectly safe. What it says is that if a majority of the servers at your butcher shop have a habit of putting their thumb on the scale, it may not mean you’re being swindled at any given time, but it’s wise to keep your eyes open when you’re in a den of thieves.

The salient argument that was made in that other debate is not about the present but about the future, when transgenic technology potentially results in more substantial and complex changes in foods than at present. So again, when in a den of thieves, keep alert and be skeptical. This is just reasonable and factual. Case in point:
Monsanto consistently outspends all other agribusiness companies and interest groups to protect and maintain industrial agriculture’s dominance over our food system … In 2008—the year the previous federal Farm Bill was completed—the company reported a whopping $8.8 million in lobbying expenditures (see table below) intended to influence decisions in Congress, the U.S. Department of Agriculture, and other federal agencies … According to documents the company filed with the Securities and Exchange Commission, it spent $100 million on advertising in fiscal year 2011, $87 million in FY 2012, and $95 million in FY 2013.
You’ve tried to make the case in the past that the GMO issue should be resolved through definitive science, comparing it to climate change. Well, except that on the issue of climate change all the national academies of the major nations of the world have repeatedly issued a clear and unequivocal position. I have yet to find such an unequivocal position on GMOs from this same impeccable source. Indeed quite the opposite. Way back in 2004 the National Academy of Sciences Committee on Identifying and Assessing Unintended Effects of Genetically Engineered Foods on Human Health issued 7 recommendations for mitigating the risks of GMOs. Ten years later, in 2014, yet another panel was convened, with no end in sight. As far as I can find, the sort of unequivocal position that they expressed on climate change has never been expressed by the National Academy of Sciences on GMOs.

Again, GMOs are almost certainly safe. Today. Some of the anti-GMO movement are crackpots. But there is tremendous business lobby support for GMOs that should give one pause, and no credible scientific body AFAIK has given absolute assurance of future safety as transgenic technologies become more potent.

Stranger On A Train has once again written what I regard as an accurate, informative, and cogent post on a complicated topic. It’s unfortunate that it was followed by a lot of one-liners providing simplistic and absolutist responses.

This happened with the effectively unregulated US supplement market, not our general food stream. If anti-GMO people are turning this into an argument against GMOs then that is ironic since it is a bed they made to lie down in.