UC Professors Weigh in on Glyphosate (AKA Roundup) and Carcinogenicity

Glyphosate, the “most widely used herbicide in the world,” is in the news a lot lately, largely because the first of thousands of lawsuits, filed by folks who used Monsanto’s Roundup (or other glyphosate-based herbicide products) for decades–who assumed it was as safe as the company claimed it was–and then developed cancer, are now coming to trial.

To those of you who might be interested in learning the lengths to which Monsanto apparently went in defending its glyphosate-based product(s), I highly recommend that you follow the Courthouse News Service articles on these trials.

The opening statement in the third case to go to trial, for example, by the attorney for a California couple who were both diagnosed with non-Hodgkin lymphoma within four years of one another after having sprayed Roundup on their residential properties for 35 years, could serve as the basis for a great movie plot (IMHO).

As described in Roundup Trial: Monsanto Used Fake Data to Win Over Regulators, Monsanto “seemingly planted one of its employees at a contract lab…in the 1970s to fake negative mouse carcinogenicity data for…glyphosate that were to be used to win regulatory approval for the weed killer in 1975; planned an attack to discredit the World Health Organization’s (WHO) cancer research agency, anticipating the agency would classify glyphosate as a probable human carcinogen in 2015 [which, nevertheless, the agency did]; and exploited ‘deep connections’ within the U.S. Environmental Protection Agency to classify glyphosate as non-carcinogenic.”

You may have heard some of these allegations before. Bloomberg reported on the Monsanto-EPA connection in “EPA Official Accused of Helping Monsanto ‘Kill’ Cancer Study” (published in March of 2017), for example.

But maybe not others, like the much older scandal at the now defunct contract lab. (This 1983 article in the Washington Post provides some general information regarding inadequate or falsified data on over 200 pesticides–including Roundup–tested by the specific contract lab mentioned in the current trial.)

Jurors serving on the current trial are also learning about a new study, published in Mutation Research in February 2019, that found “a compelling link between exposure to glyphosate-based herbicides and an increased risk of non-Hodgkin lymphoma.” The first author of this new scientific paper, which comprises a meta-analysis of multiple previously published studies that were designed to determine whether glyphosate exposure increases cancer risk, is an adjunct professor of toxicology with the School of Public Health at the University of California (UC) in Berkeley named Luoping Zhang.

Dr. Zhang, along with two of her co-authors on the Mutation Research paper, had been members of EPA’s 2016 scientific advisory panel on glyphosate. But “Zhang was ‘so outraged’ by the EPA’s failure to follow its own herbicide-assessment guidelines” that she resigned from the advisory panel to carry out the meta-analysis herself. The resulting study is focused on the evidence pertaining to groups of people most highly exposed to glyphosate, and also takes into account the most recent publication on the Agricultural Health Study, a large and long-term study of the effects of pesticides on U.S. farmers that was initiated in 1993. One of Monsanto’s complaints about the WHO’s 2015 determination that glyphosate is a probable human carcinogen had been that the agency hadn’t taken the most recent results from the Agricultural Health Study (AHS) into consideration. (WHO hadn’t taken them into consideration because those results hadn’t been published yet.) But after considering all the available published data–including the latest data from the AHS–Zhang et al.‘s results still indicated that high exposure to glyphosate increased a person’s risk of developing non-Hodgkin lymphoma.

Another UC Berkeley professor, Elena Conis of the Graduate School of Journalism and Center for Science, Technology, Medicine and Society, recently wrote an overview of the history of how pesticides have been regulated in the U.S. that sheds some light on how we got to this point where pesticides “are innocent and on the market until…enough independent science has produced evidence of harm….” In her Perspective piece in the Washington Post, Dr. Conis mentions that the EPA classified glyphosate as a carcinogen in 1985 but “reversed course after six years of correspondence with Monsanto executives;” that since then Monsanto has asked EPA to base its decisions on Monsanto-commissioned science; and that “[i]n one instance, the EPA ceded to industry requests to remove a certain scientist from a glyphosate safety review panel.”

On the other hand, I, for one, am grateful to Dr. Zhang for removing herself from the 2016 glyphosate review panel so that she could conduct the kind of independent science that is so desperately needed to protect humans from capitalists who put their bottom lines ahead of our collective health. U.S. regulatory agencies need to correspond more with scientists who are not working for, or otherwise aligned with, the companies which make money by developing poisons (which is what pesticides were called until after WWII) to spray on our food crops.

In the meantime, while the safety of glyphosate is being debated in the courts, there are steps you can take to limit your exposure to it from the food you eat.

Traditional crops die if glyphosate is applied to them, but crops genetically engineered (GE) to tolerate glyphosate do not. So avoiding GE fruits, vegetables and grains (AKA GMOs) should reduce your intake of glyphosate.

However, some non-GMO crops, like wheat and oats, are now sprayed with glyphosate just prior to harvest to speed up their desiccation–and the regulatory agencies have responded to this new farming practice by increasing the legally permissible levels of glyphosate residues on those crops (see Zhang et al. and references therein for more information on exposure to glyphosate). Consequently, the best way to avoid glyphosate in these crops is to buy products from crops that have been organically grown; glyphosate use is not allowed in organic farming per the current USDA organic standards.



Posted in Biotechnology | Tagged , , , , , , , , | Leave a comment

“Modified” the Film: Upcoming Screenings

A new film dubbed “A Food Lover’s Journey Into GMOs” was released recently and I highly recommend it…both as an interesting, beautiful and poignant story of its own and also as a means toward filling in gaps in the GMO story as told, for example, in the film Food Evolution (which has been called propaganda by many).

It’s called Modified. Thus far, it’s received 13 film festival awards (including four Audience Choice awards) and well known chef Jacques Pépin calls it “a very personal, tender, touching tribute and a well-researched, enlightening and powerful documentary.”

Canadian Aube Giroux, who wrote, directed, edited and produced Modified, tells me that “audiences respond very strongly and favourably to the film.” I can see why. As described on its website, Modified intimately portrays a “mother-daughter quest for answers” about GMOs, interweaving a “visual celebration of food”, cooking, gardening and family legacy with an investigation into the “extent to which the agribusiness industry controls our food policies.” Modified makes a “strong case for a more transparent and sustainable food system.”

Check out the 2019 schedule for screenings of Modified. It’s being shown in Nevada City on Feb. 24 at Nevada Theatre, for example. And it will be screened during the San Luis Obispo International Film Festival March 12-17 and during the Phoenix Film Festival April 4-14.

IMHO, Modified does a much better job of laying the groundwork for a more civil and productive societal debate about GMOs than efforts like Food Evolution. But view it for yourself and see if you agree.

Posted in Biotechnology | Leave a comment

New Salk Institute Study Reveals More Detailed Picture of “Scrambled Nature” of Gene Insertions in GMOs

Plant molecular biologists have known for decades that the techniques they use to genetically engineer plants are error prone and can result in GMOs with unintended:

  • mutations in host plant genes,
  • insertion of vector backbone DNA sequences,
  • small duplications or deletions of inserted or host DNA, and/or
  • large rearrangements of host plant chromosomes.

Other unintended changes are also possible; for example, Monsanto’s commercially available NK603 corn unintentionally produces a hybrid RNA molecule derived from sequences of the foreign DNA inserted into that product and sequences from the recipient corn variety’s DNA adjacent to the insertion site.

But, according to the new study published by Jupe et al., “detailed understanding of structure and epigenomic status of insertion events [had been] limited” by the technologies available to researchers; “plant scientists didn’t have the molecular tools” that could enable them to “see” the multiple effects that inserting pieces of foreign DNA into a host plant’s genome have had on those genetically engineered (GE) genomes in a single “picture” until recently.

For this new study, conducted under the supervision of Joseph R. Ecker, a highly respected academic plant molecular biologist at the Salk Institute for Biological Studies, researchers used “state-of-the-art long-range sequencing technologies…to provide new insights into the structural impact of inserting foreign [DNA] fragments into plant genomes….”

These authors, primarily associated with the Salk Institute but including a scientist from the Donald Danforth Plant Science Center and two others from the J. Craig Venter Institute, utilized the state-of-the-art techniques to elucidate unintended changes in the genomes and epigenomes of Arabidopsis thaliana plants that had been genetically engineered using the Agrobacterium-based method. [Arabidopsis is a model plant organism used by many academic researchers. The Agrobacterium-based method of genetic engineering involves the intended transfer of a specific piece of DNA (the transferred DNA or “T-DNA”); this method is good enough at mutating host plant genes that it was used by plant scientists in an effort to mutate every gene in the Arabidopsis genome. Many commercially available GMOs were created using the Agrobacterium-based method of genetic engineering.]

The new study revealed the “scrambled nature of T-DNA and vector backbone insertions and rearrangements in high detail” and “uncovered various effects of T-DNA insertions on the adjacent chromatin landscape.” Unintended “intra- and interchromosomal rearrangements” were discovered, for example, as well as unintended “alterations of chromatin and thus chromatin structure and functionality.” With “unprecedented detail” this study reveals “novel insights into the impact of these events on plant genome/epigenome integrity.”

The authors point out that this kind of “Knowledge of structure variations induced by transgene insertions…as well as evidence for epigenetic changes to the host genome is crucial from scientific as well as regulatory perspectives.”

I agree. We just don’t know enough about genomes and epigenomes, and how randomly inserting foreign pieces of DNA into them and scrambling them will affect them. Therefore, I think U.S. regulators should take a more precautionary approach to regulating GMOs, and require developers of GMOs to provide information about the integrity of the genomes and epigenomes of their products prior to commercializing them.

But the FDA has never required developers of GMOs to provide the kind of crucial information about structure variations induced in their products by transgene insertions that Jupe et al. addresses…even though older techniques for revealing most of them have been available for decades. And some who have provided information about the “scrambled” genomes in their GMOs to the FDA voluntarily–like Monsanto did for NK603–have gone ahead and commercialized those scrambled products anyway.

Jupe et al. conclude the Discussion of their results by stating that “Our findings pave the way for structural genomic studies of transgenic crop plants….”

Maybe. But will developers of GMO crops follow this newly paved path? Will FDA make them?

Or will GMOs with scrambled genomes and epigenomes continue to be commercialized?


Posted in Biotechnology | Tagged , , , , , , , , , | Leave a comment

Golden Rice: Of Good Intentions, Insertional Mutants, Human Error, and the Need for Better Regulation of GMOs

After learning that the genetically engineered (GE) Golden Rice “event” being bred into varieties of rice favored by Indian farmers turned out to have a mutation—a mutation created as a result of the genetic engineering process itself (you can check out my first post on this subject here)—I was curious to learn more about the history of this genetic engineering project undertaken for humanitarian purposes.

The Golden Rice project is an attempt to use genetic engineering to alleviate vitamin A deficiency, a major cause of blindness, illness and death—mostly among young children—in developing countries where diets can consist primarily of rice and sometimes little else in the way of vegetables or other foods that contain beta-carotene, a compound that human beings can then convert into vitamin A. The project was initiated in the early 1990s and was widely publicized in 2000 when a photo of Ingo Potrykus, one of its “founding” scientists (along with Peter Beyer), appeared on the cover of Time magazine.

But it’s been 18 years since then and Golden Rice is still not available to the world’s poor who might benefit from it. Why is it taking so long to deliver this humanitarian product?

A very revealing paper by a member of the Golden Rice Humanitarian Board, Adrian Dubock, provides some answers. In it, Dubock asks “What can Golden Rice’s development history and trajectory teach us?”

SPOILER ALERT! My answer to that question—which is essentially diametrically opposed to his—is this: Check early in your GE project to identify any unintended insertional mutations in your prototype crops that were caused by the genetic engineering process, and then throw any GE “events” that have such a mutation out of your product development pipeline! (Dubock’s answer, on the other hand, might be summed up as: international regulation of GE crops, in the form of the Cartagena Protocol, impeded our progress every step of the way; more on whether regulation of GE foods is currently adequate at the end of this post.)

Are Other Developers of GE Crops Neglecting to Discard the Unintentional Mutants Created by the Genetic Engineering Process?

Golden Rice’s history also begs the questions: how many other developers of GE crops have neglected to screen their GE prototypes for insertional mutants? Are there insertional mutants among the GE crops currently on the market? (I’ve tried, unsuccessfully, to determine whether Monsanto’s NK603 GE corn was screened for this potential problem, for example.)

But I’m getting ahead of myself….

Timeline of the Development of Golden Rice

What follows is a timeline of the development of Golden Rice focused on events relevant to the problem of the potential for unintentionally creating GE mutants, a problem still faced by all developers of GE crops using the Agrobacterium-based and biolistics methods. This timeline is based on the information contained in “The present status of Golden Rice” by Adrian Dubock. (The information I mention from Dubock’s article can be found on the pages of it indicated in parentheses below; emphases are mine.)

2000: Ye et al. publish a paper describing the first “prototype” Golden Rice; the inventors of Golden Rice trade “commercial rights in the technology to Zeneca [soon to be Syngenta], in return for the companies [sic] support for the inventor’s humanitarian vision;” Zeneca is granted exclusive rights to Golden Rice technology “free of charge for humanitarian applications, but royalty bearing for commercial applications” (p.71).

The “Golden Rice Humanitarian Board is created “to advise the inventors” during its development and one of its “first agenda items was to hear the advice of a Zeneca biotechnology regulatory specialist about the molecular characteristics required of a genetically transformed GMO-crop to ensure that it would be able to be registered for use under the regulations to be derived from the very recently (2000) published, but not yet in force (2003) Cartagena Protocol on Biosafety” (p.73); the US biotech industry pays for television advertising “implying fields of golden rice were [already] growing in US fields…” and Gordon Conway, President of the Rockefeller Foundation, joins “anti-GMO activist Vandana Shiva in agreeing that ‘the public relations uses of golden rice have gone too far’” (pp.72-3).

2001: A license agreement is signed by inventor Potrykus and Dr. Ron Cantrell, director of the International Rice Research Institute (IRRI) in the Philippines, and samples of the Golden Rice prototype are hand-delivered to IRRI two days later (p.73).

2002: The Humanitarian Board asks the “network of public sector rice research institutions” to create more than 1000 additional transformation events “from which it was hoped an improved transformation event could be selected collaboratively, to be taken forward as the one lead event by all Golden Rice licensees” (p.73).

2003: New GE “events” of Golden Rice [GR1], the best of which accumulates 13 micrograms (μg) total carotenoids per gram (g) of rice, as opposed to the 1.6 µg/g in the prototype, were created and plans to conduct field and human feeding trials with some of them are made; an additional version of Golden Rice [GR2], with even higher levels of beta-carotene, looks promising in Syngenta’s labs (pp.73-4).

2004: Field trials of GR1 Golden Rice are conducted in the US; Syngenta donates GR1 and 13 GR2 “events,” at least the latter “of which were considered by [Syngenta Biotechnology, Inc.] scientists and regulatory specialists to be ready for and capable of complying with regulatory studies and standards” (p.76), to the Golden Rice Humanitarian Board and announces that it has “no commercial interest in the Golden Rice project” (p.75); the Humanitarian Board decides to concentrate efforts on 6 of the 13 GR2 individual transformation “events” donated by Syngenta (p.76).

2005: Paine et al. publish a paper describing the development of the GR2 events.

2006: IRRI requests, and Syngenta provides, molecular data on the 13 GR2 events (p.76).

2008: The field phase of a feeding trial with Chinese children is conducted; IRRI plants the first confined field trial of events of GR1 and GR2 Golden Rice in Los Banos, Philippines (p.77).

2009: A meeting of the Humanitarian Board is held in March to choose the top 2 Golden Rice events for product development; results of the feeding trial with human adults in the US are accepted for publication and presented at the meeting (p.77); agronomic data on 3 GR1 and 6 GR2 events, introgressed into 4 different indica rice varieties, were considered and Dr. S.R. Rao (Dept of Biotechnology, Government of India) asked “if there was any molecular data available to support the decision making. No such data was forthcoming (although IRRI had received it in 2006, it appeared to have been forgotten)” (p.78); nevertheless, based on the data the Board did have at hand, event GR2G was selected as the “Lead Transformation Event, with event GR2R as a back-up event if needed” (p.78); by December 1st scientists at IRRI had examined the molecular data on the GR2 events (provided by Syngenta back in 2006) and realized that the DNA inserted into GR2G, the lead event and the one used in the human bioconversion trials, contained an unexpected, unintended deletion of ~400bp; the newly found/examined molecular data also indicated that in both GR2G and GR2R the genetic engineering process had created mutations at the site in the rice genome where the foreign DNA had been inserted; but, “[d]espite the summary slide provided by IRRI, The Board had not reviewed, nor did most have the training, to ‘review all sequence data’ in any meaningful way, and it is unclear which other individuals had or the level of scrutiny afforded to it,” the decision was nevertheless made to drop the GR2G event and “bring forward” the GR2R event as the lead event (p.79).

2010: The grant to Peter Beyer from the Bill and Melinda Gates Foundation terminates; “Instead the Foundation intended to award a grant for development of Golden Rice itself to IRRI, for management of Golden Rice out of IRRI” (p.80).

2011: By October 3, GR2R seed had only been supplied to research institutes in two countries, India and the Philippines; the “inventors and the public sector Golden Rice licensees in other countries are very frustrated by this slow progress” (p.80).

2012: “Dr. Tang’s research with Chinese children, initially spoken of in 2003/2004 showed that” a bowl of cooked Golden Rice [GR2G?] “can provide ~60% of the Chinese Recommended Nutrient Intake of vitamin A for 6-8-y-old children;” “Greenpeace issued a press release condemning use of a GMO-crop, Golden Rice, with Chinese children as ‘guinea pigs of American researchers;’” [Tang et al. (2012) was later retracted (and China sacked officials in that country who were associated with the experiment) due to failure of the researchers to follow Tufts University rules regarding securing consent from research participants]; 5 multi-location field trials with GR2R are planted in the Philippines (p.80).

2013: In August one of the field trials was destroyed by anti-GMO demonstrators; data from the other 4 field trials indicated a “yield-drag” in Golden Rice GR2R compared to wild-type rice; in December, the “IRRI Network Coordinator appeared to recall the issue summarized in his December 2009 slide” indicating that the new lead event, GR2R, was an insertional mutant (pp. 80-1).

2014: IRRI posts information on its website about the poor yields with GR2R [but fails to mention the fact that it contains a mutation caused by the genetic engineering process] and that “a decision has been reached to move forward from work solely focused on GR2-R to also include other versions of Golden Rice, such as GR2-E and others” (p.81); Adrian Dubock publishes “The Present status of Golden Rice” in the Journal of Huazhong Agricultural University.

What can this history of Golden Rice teach us?

This is an astounding story. A group of humans with all the best of intentions, who apparently tried to take into account–from the very start of their work together–the regulatory requirements in the various countries for creating, transporting, and marketing a GMO food, and yet years of time and loads of effort and who knows how much money (the Gates Foundation?) were wasted on Golden Rice events that should have been culled from the “production pipeline” by 2005 (or 2006 at the latest). Sad!

Errors were made by multiple humans involved in this story. Why did Syngenta hand over mutant Golden Rice events to the Humanitarian Board in the first place? Why didn’t scientists at IRRI thoroughly examine the molecular data on those events right after they had specifically requested the information from Syngenta? Why show molecular data indicating that 2 of the 3 top Golden Rice events have their foreign DNA inserted into rice genes to a decision-making body incapable of understanding the ramifications of those mutations (that were caused by the genetic engineering process)?

We don’t know whether the insertional mutations in Golden Rice events GR2G and GR2R made the rice grains harvested from those plants unsafe for human consumption. But most mutations are deleterious, and determining whether a particular mutation would cause a problem(s) in rice that would make it unsafe for consumption would require further investigation (of each GE mutant food variety). The most expedient way to deal with insertional mutants caused by the genetic engineering process is to identify them early and eliminate them from commercial development.

Glenn et al., mostly employees of Monsanto, indicate that they now do cull GE insertional mutants in this way. But since they also indicate that they now eliminate GE events with other imprecise manifestations of the genetic engineering process from their commercial pipeline, when Monsanto certainly has not always done that, could there be any GE mutants already in our food supply? And do other developers of GE food crops follow the procedures now used by Glenn et al.?

My take on the Golden Rice story is that we need better, truly science-based regulation of GE foods, regulation that recognizes the imperfections in the technology and regulates its putative products accordingly. Regulators in every country around the world should deny “approval” of any GE food crop that contains a mutation caused by the genetic engineering process. They should do so because genetic engineering is imperfect, and humans–even those with the best of intentions–will continue to make errors, and combining this imperfect technology with error-prone humans could have negative effects on our food supply.



Posted in Biotechnology | Tagged , , , , , , , , , , , , , , , , , , , , , | 9 Comments

Golden Rice Showcases Both the Potential Benefits and Potential Risks of Crop Genetic Engineering

It’s been nearly two years since a group of Nobel laureates published a letter supporting “Precision Agriculture (GMOs)” and, more specifically, Golden Rice, the genetic engineering project first embarked upon in the mid-1990’s to “reduce or eliminate much of the death and disease caused by a vitamin A deficiency (VAD), which has the greatest impact on the poorest people in Africa and Southeast Asia.” And although Golden Rice with its potential benefit is still not available to people suffering from VAD, a couple of significant technical and other events in the project’s development have occurred over the last couple of years that showcase some of the imprecision and potential risks inherent in the technology used to create this genetically engineered (GE) rice.

The potential benefit of Golden Rice has yet to be realized

The prospect of reducing or eliminating much of the death and disease caused by VAD is certainly an intended potential benefit of Golden Rice. But before that potential benefit might be realized, there are still many issues that remain to be addressed.

For one thing, we still don’t know whether Golden Rice will be effective in treating VAD. According to the International Rice Research Institute (IRRI), the organization developing Golden Rice “for cultivation and use in human food in certain south and southeast Asian countries,” “bioefficacy studies to determine the effect of Golden Rice consumption on various measures of vitamin A status” in humans still need to be carried out, and “appropriate regulatory authorization and institutional review board clearances” for such studies have not been obtained as of yet.

Additionally, regulatory “authorization for the unconfined environmental release of GR2E Golden Rice” and the “use of GR2E Golden Rice in food and feed, or for processing,” in the Philippines or any other country in Asia, Africa and Latin America where VAD is a serious problem, has not yet been obtained.

On the other hand, IRRI has received what it refers to as a “positive food safety evaluation” of Golden Rice GR2E from the US FDA (as well as from Food Standards Australia New Zealand and Health Canada). The short letter from FDA conveying this “positive food safety evaluation” is odd for several reasons, first just as an example of how voluntary consultation about newly developed GMOs works at that US agency. The safety-related content in FDA’s letter to IRRI is comprised primarily of “information IRRI has provided” and conclusions “it is [FDA’s] understanding” IRRI has reached. Non-administrative, safety-related FDA input is limited to the agency’s usual consultation-closing statement: “Based on the information IRRI has presented to FDA, we have no further questions concerning human or animal food derived from GR2E rice at this time. However, as you are aware, it is IRRI’s continuing responsibility to ensure that foods marketed by the firm are safe, wholesome, and in compliance with all applicable legal and regulatory requirements.” (One can see why IRRI does not refer to FDA’s position on Golden Rice as an “approval.”)

Another odd thing is that IRRI informed FDA that “GR2E rice is not currently intended for cultivation or marketing in the United States.” Which begs the question: why, since “according to IRRI, GR2E rice is intended for cultivation and use in human food in certain south and southeast Asian countries…for populations in which vitamin A deficiency is common,” did IRRI go through the “regulatory” process with the US FDA in the first place? IRRI’s answer? “…GR2E rice, or human and animal food products derived from GR2E rice, may enter the U.S. food supply via imports from countries of production.” It’s not clear whether IRRI means that the US may knowingly import Golden Rice or that its non-GMO rice imports might be contaminated with Golden Rice or both; perhaps IRRI is just trying to cover all its bets. In any case, this possibility of Golden Rice being imported into the US explains why 3 of the 6 paragraphs in FDA’s “consultation closure letter” to IRRI deal with the issue of GMO labeling.

The most striking point made in the FDA letter, however, is that the “concentration of β-carotene in GR2E rice is too low to warrant a nutrient content claim.” The whole idea of Golden Rice is to provide a necessary dietary nutrient to people at risk of, or suffering from, vitamin A deficiency…and the levels are too low to warrant a nutrient content claim with FDA?

The explanation of this paradox lies partly in the amounts of rice that Americans versus Filipinos (for example) consume. According to IRRI, to meet the FDA requirement for a nutrient claim “10 percent or more of the recommended daily intake (RDI) for vitamin A must be present as beta-carotene” in the 45 grams of rice that Americans, on average, consume daily; and the amount of beta-carotene in Golden Rice is less than that. (If the 10% threshold had been reached, I believe premarket review and/or official approval by FDA would have been required.) But the average Filipino consumes more than 6 times that much rice, and IRRI expects that if all of that was Golden Rice, “30-50% of the estimated average requirement for vitamin A” could be met in the “subgroups at highest risk of vitamin A deficiency.”

The imprecision of genetic engineering and its effects on Golden Rice 

But another reason why the concentration of beta-carotene in today’s Golden Rice is relatively low (~7.31 micrograms/gram, ~10% of the level found naturally in carrots-from safety assessment documents submitted to the government of the Philippines) is that what had been the most advanced variety of Golden Rice in IRRI’s product development pipeline, a variety with substantially higher levels of beta-carotene, GR2-R1, turned out to be a genetically engineered mutant with no market potential.

GR2-R1 had been a very promising Golden Rice “event,” with levels of beta-carotene more than twice as high those in GR2E (Paine et al. 2005). It was so promising that it was being bred into a popular rice variety called Swarna in preparation for its use by farmers in India. But the plants produced as a result of this breeding effort turned out to be stunted, pale green and have drastically low yields. To determine what was causing these problems a group of scientists in New Delhi (Bollinedi et al. 2017) carried out a molecular characterization of GR2-R1 that revealed that the foreign genes responsible for production of beta-carotene in GR2-R1 rice grains had been inserted into a rice gene called OsAux1, mutating it. The protein product encoded by this gene provides for proper function of a master growth regulator (auxin) in rice that is “involved in every aspect of plant growth and development” (Bollinedi et al. and references therein); mutating it in GR2-R1 rice caused various abnormalities in plant growth and development.

I am not at all surprised that the genetic engineering process caused this mutation. After all, we’ve known for more than 25 years that the Agrobacterium-based methods of genetic engineering cause frequent insertional mutations in recipient plants; Bollinedi et al. (2017, and references cited therein) state that 35-58% of insertions of foreign DNA sequences disrupt recipient plant genes.

What I am surprised about is that no one had (apparently) ever checked to make sure that this GE rice plant did not contain such a GE mutation prior to it being readied for farmers’ fields. Genetic engineering and associated technologies provide genetic engineers with the ability to identify such insertional mutations. Genetic engineers should be doing so early in the development of products intended for commercial release and eliminating any identified mutants from their product development pipelines. And regulatory agencies should ensure that developers of GMOs have carried out this necessary, straightforward screen of potential products.

Another source of abnormalities in GR2-R1 rice related to genetic engineering

Bollinedi et al. (2017) identified an additional problem with GR2-R1 rice, a problem that could affect other GR2 Golden Rice events as well, like the GR2E rice being readied for commercial release.

The foreign genes responsible for increasing levels of beta-carotene in all of the GR2 “events” of Golden Rice are meant to be expressed only in rice grains because expressing them in other parts of the plant could unintendedly disturb other biochemical pathways that share a common substrate, such as those involved in the biosynthesis of chlorophyll or various plant growth regulators. To accomplish this specificity, genetic engineers at Syngenta (Paine et al. 2005) spliced the “promoter” region of a rice gene called Glutelin I, which is only expressed in grain (the promoter is responsible for turning a gene on or off), to the protein-coding regions of the genes involved in beta-carotene synthesis that they wanted to insert into rice plants; then they inserted the resulting chimeric genes into rice plants via genetic engineering.

But in characterizing the abnormal GR2-R1 Golden Rice plants (produced by Syngenta as mentioned above), Bollinedi et al. found that expression of the foreign chimeric genes was not grain-specific as had been intended, the foreign genes were expressed in leaves as well. These scientists hypothesized that this “leaky” expression of the chimeric foreign genes was responsible for the pale leaves and (some of the) growth regulator-related abnormalities in GR2-R1 rice plants (because biosynthesis of green chlorophyll pigments and expression of plant growth regulators had been disrupted due to competition with the GE enzymes for beta-carotene biosynthesis). They documented dramatic alterations in the expression of four key plant growth regulator genes in support of their hypothesis.

The future of Golden Rice

In light of these problems with GR2-R1 Golden Rice that are related to the process of genetic engineering, IRRI is now concentrating on developing GR2E Golden Rice for commercial release. IRRI (in conjunction with the Philippine Rice Research Institute) submitted an application for a biosafety permit for the “direct use in food, feed, or for processing of GR2E Golden Rice,” (http://irri.org/golden-rice/faqs/what-is-the-status-of-the-golden-rice-project) to the Department of Agriculture-Bureau of Plant Industry (DA-BPI) in the Philippines in early 2017. (A link to the collection of Golden Rice data files can be found on this website: http://biotech.da.gov.ph/Decision_docs_jdc_direct.php, about 2/3 of the way down the page.)

Information in the submission package appears to indicate that GR2E Golden Rice has been checked and that a mutation was not created at the site in the rice genome where the foreign genes were inserted. I’m not as convinced by the submitted data that the “leaky” endosperm promoter issue has been adequately analyzed.

I hope Golden Rice will be successful in reducing vitamin A deficiency. But we need to remember that “Precision Agriculture (GMOs)” is not as precise as some would have you believe. There is a lesson to be learned from GR2-R1 Golden Rice, and it is to be more vigilant about the less precise aspects of crop genetic engineering.

Posted in Biotechnology | Tagged , , , | 5 Comments

Food Evolution Film Neglects to Mention Important Facts…Like Glyphosate is a Probable Human Carcinogen

The film Food Evolution, despite being narrated by Neil deGrasse Tyson, has been called “a slick piece of GMO propaganda” by Marion Nestle, a prominent nutrition scientist at NYU who was interviewed for it. In response to Nestle’s tweet on the subject, Michael Pollan, the journalism professor at UC Berkeley who also appears in the film, tweeted: “My experience and take much the same.” And a group of more than 45 “UC Berkeley faculty, students, alums, and community members” have also signed a statement calling this film “a piece of propaganda.”

Why? Especially since ads for the film encourage viewers to “Feast on Facts“?

Because the film neglects to mention some facts that are important for understanding the issues presented in the film, facts that are also important for getting beyond the currently polarized state of the GMO debate.

One revealing example of this cherry-picking is the film’s handling of an article published in The New York Times titled “Food Industry Enlisted Academics in G.M.O. Lobbying War, Emails Show.” Well over half of this article is devoted to emails linking three academic scientists–Kevin Folta, “chairman of the horticultural sciences department at the University of Florida,” Bruce M. Chassy, “professor emeritus at the University of Illinois,” and David R. Shaw, “vice president for research and economic development at Mississippi State University”–to Monsanto “and its industry partners.” Less than 20% of the article (by my estimate) is focused on Charles M. Benbrook, “who until recently held a post at Washington State University,” and his ties to the organic foods industry.

But only Benbrook is mentioned in Food Evolution. Viewers of the movie don’t hear anything about Folta, Chassy or Shaw.

In order to have meaningful engagement that will increase understanding of the issues involved in and affected by genetic engineering, and contribute to more informed development of future public policies on regulating the products of this powerful technology, we need all the facts. Not just the ones that zealous GMO proponents cherry-pick to tell us about.

Feasting on propaganda will only further polarize the GMO debate.

I was invited to participate in a panel discussion of the film at the University of San Francisco earlier this month. What follows is a copy of the remarks I made.


Good evening everyone.

As a molecular geneticist and a former genetic engineer, I am so very disappointed in this film…

because I believe that scientists using a new technology, especially one that contributes to our food supply, have a responsibility to be abjectly honest when explaining to the public what we know about how the technology works, how it differs from “traditional” methods, and any possible risks that might be associated with it.

And a film like this one, claiming to be science-based, with iconic public scientists like Neil degrasse Tyson and Bill Nye participating in the project, should bear that same responsibility.

Participants in a recent workshop called “Scientific Uncertainty and Professional Ethics,” sponsored by the National Science Foundation (NSF), came to a similar conclusion. They came to the conclusion that scientists should aim to “provide all the information needed to help others judge the value of their work, rather than to steer that judgment in a particular direction.”

This film fails on both counts. It doesn’t provide all the information needed to help others judge GMOs and it steers judgement in a particular direction.

The reason scientists need to be abjectly honest when explaining genetic engineering to the public is because… only by considering all the pertinent, available information—the whole truth about crop genetic engineering as we know it—can society at large make good, informed decisions about how to use and control this powerful technology.

Instead, this film leaves out important information that is crucial to an informed public debate about GMOs.

Back in the early ‘90s when I was working for a small start-up ag biotech company called Calgene, I thought we did a pretty good job of being transparent and abjectly honest, with the public and with the FDA and other regulatory agencies, about what we knew about how genetic engineering worked, how it differed from traditional breeding, and its possible risks.

We knew adding foreign genes to plants could cause mutations in the recipient plant, for example, and that sometimes the inserted DNA sequence had been changed from the DNA sequence we had intended to insert. We therefore suggested to FDA ways that we would identify and minimize such unintended effects. And frankly, I was surprised when, in May of 1992, before its scientists had thoroughly examined all the data we had sent them, FDA decided that, with only a couple of exceptions, regulation of GE food and feed crops would not be required by that agency; it put a voluntary consultation process in place instead. It remains a voluntary system to this day. [See my previous blog post for more information on the timing of FDA’s GMO policy in relation to its review of Calgene’s safety data.]

Calgene was also transparent in that it voluntarily labelled its GE tomatoes when they were first sold in grocery stores. And the public’s response to Calgene’s transparency was mostly positive. Our GE tomatoes flew off the shelves.

So I think the agricultural biotech industry got off to a pretty transparent and honest start.

But other companies have not been as transparent as Calgene was. And I believe that the lack of transparency, and the lack of abject honesty about the imperfections inherent in the technology of genetic engineering, has played a big role in the polarization of this issue over the last two decades.

Transparency gets paid a little lip service in this film, but Food Evolution still fails pretty spectacularly at being abjectly honest about genetic engineering.

For example, it leaves out important information pertaining to the safety of glyphosate, the active ingredient in Monsanto’s Roundup herbicide. It neglects to mention the fact that the arm of the World Health Organization that classifies compounds as carcinogenic—or not—the International Agency for Research on Cancer (IARC), has classified glyphosate as an animal carcinogen and a probable human carcinogen. [Since the release of Food Evolution, Monsanto sued California for using IARC’s classification to require warnings of glyphosate exposure; Monsanto lost that law suit and, on April 19, 2018, Monsanto lost its appeal of that decision as well.]

This is important information that must be taken into account in any objective discussion about the safety of glyphosate, especially since glyphosate—due to the many millions of acres of GMOs engineered to be tolerant of it that are grown and sprayed with it throughout the world—is now the most widely used herbicide on the planet.

There is no excuse for this intentional omission, and it calls into question not only the film’s honesty but its objectivity as well.

I was also disappointed with the way the film handled coverage of the safety study by Séralini and co-workers in which rats were fed either glyphosate or the GE corn called NK603 over the course of their lifetimes.

First, let me provide you with a little more information that you will need to judge the value of this study. As I’ve mentioned, unintended, off-target changes can occur in crop plants as a result of the genetic engineering process. Well, it is to check for possible negative consequences of unintended changes that GE crops/foods are fed to animals in studies like Séralini’s. We carried out similar (although not as long term) studies with our tomatoes at Calgene, and scientists at Monsanto and elsewhere also have done the same  with their GE products.

Séralini’s study was peer-reviewed and originally published in the respected international journal Food and Chemical Toxicology; it was in print for more than a year when it—very unusually—underwent a thorough review by the journal’s editor-in-chief, who reviewed not only the submitted manuscript and all the reviewers’ comments, but also the raw scientific data from Séralini’s lab. As a result of his review, he [and I quote] “unequivocally…found no evidence of fraud or intentional misrepresentation of the data” and deemed Séralini’s results “not incorrect” but “inconclusive.”

And yet, despite the fact that many peer-reviewed scientific papers present results that are not conclusive, and the fact that inconclusiveness is not a benchmark for retraction of a scientific paper, he retracted the paper anyway. The whole episode was highly unusual for a scientific community.

I say that Séralini’s original study should never have been retracted. And Professor Fred Gould, who was the chairman of the committee that put together the most recent National Academy of Sciences report on GMOs, told me [during the “on the record” Scientific Uncertainty and Professional Ethics panel discussion of GMOs and scientific uncertainty that I mentioned above] that he agreed that the paper should never have been retracted.

In the aftermath of this highly unusual Séralini retraction, I have read, in an article in Nature and elsewhere, that the inconclusiveness of the study stems from the number of control rats used, which has been deemed inadequate for attaining statistically significant conclusions. The statistician quoted in the Nature article said that, and I quote, “The study needs replicating by a truly independent laboratory using appropriate sample sizes.”

This suggested course of action is the more normal scientific response to a controversial paper…i.e., repeat the study and see if you get the same results the second time around.

Since Séralini’s results have been deemed inconclusive, we don’t fully understand what may, or may not, be unintendedly going on in rats that consume GE NK603 corn or glyphosate over the course of their lifetimes. And especially in this case, when the original study suggested—albeit inconclusively—that consuming glyphosate or GE NK603 might cause ill effects in rats, the study should definitely be repeated, and with more control rats. And frankly, I am surprised that the FDA has not required Monsanto to do so. [See this blog post for information on the unintended molecular discrepancies in NK603.]

The Séralini controversy illustrates why each GMO should be assessed on a case-by-case basis. Unfortunately, the way GMOs are currently “regulated” in the United States, some GMOs can slip through loopholes without pre-market regulation.

The Séralini controversy also illustrates why, as the World Health Organization has stated, and I quote: “it is not possible to make general statements on the safety of all GM foods.” That is because they should be assessed on a case-by-case basis to look for any that may prove problematic.

There have been several examples of problematic GMOs, a couple of which have been commercialized. And then there is NK603 [which is still on the market and] for which the jury is still out in my opinion.

I don’t believe that we should throw the genetic engineering baby out with the bath water. But we need to keep in mind that technologies can be used in many different ways: carefully or carelessly, in service to the less fortunate or for profit, or even—as Nobel laureate Richard Feynman once said—for good or for evil.

GMO foods have been on the market now for nearly 25 years. It is long past time to have an abjectly honest and truly informed public debate about how to use and control the powerful technology crop genetic engineering.

Unfortunately, this film, with its cherry-picked information, will not help us do that.

Thank you for your attention.

[I received a $300 honorarium for participating in this University of San Francisco event.]

Posted in Biotechnology | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 4 Comments

Update on “Extra DNA” and Other Problems with Crop Genetic Engineering

I received an email recently from a distinguished professor of plant sciences who encouraged me to update my knowledge of the “extra DNA” problem I mentioned in an article published in the January 2018 issue of Comstocks magazine. He sent me a copy of “Bringing New Plant Varieties to Market: Plant Breeding and Selection Practices Advance Beneficial Characteristics while Minimizing Unintended Changes“–a paper published in the latter half of 2017 and authored by 13 people (Glenn et al.), 10 of whom were employees of Monsanto Company–to help me do that. He indicated that Glenn et al. “describes all of the procedures, checks and tests that are done on commercialized transgenic traits to address the problem” that I had told the author of the Comstocks article has not been solved in 25 years.

Monsanto’s Current Selection Practices, According to Glenn et al.

I have to admit that I am pretty impressed with the procedures, checks and tests carried out on potential genetically engineered (GE) crop products as documented by these (primarily) Monsanto authors. For example, they indicate that molecular analyses are conducted “to ensure: (i) that only one copy of the DNA insert was in the selected events, (ii) the intactness and integrity of the DNA insert, (iii) the absence of any undesired DNA from the transformation process (e.g. the vector backbone), and (iv) that the DNA insertion had not interrupted endogenous genes.” Additional RNA and/or protein analyses “to confirm that the intended gene products were being produced” are also mentioned in the paper.

I think it should be mandatory for all developers to conduct all of these tests, and for any GE “event” (i.e. individual GE plant) being brought to market to have successfully passed them all.

The “Extra DNA” Problem is Still a Problem

But the bottom line is that the “extra DNA” problem is still a problem. Vector backbone sequences (and other unintended DNA, see below) can still get unintentionally inserted into GE crop plants. Therefore, this problem has not been solved; Monsanto still has to check to ensure “the absence of any undesired DNA from the transformation process (e.g. the vector backbone),” and that is the “extra DNA” problem I referred to in the Comstocks article. In fact, according to Glenn et al., Monsanto checks for “extra DNA” not just once, but twice during the course of bringing a new GE plant variety to market. At Calgene, Inc., back in the early 1990’s, we also checked for “extra DNA” in our tomato, cotton and brassica GMOs, and then threw out any of those GE plants that had any. Based on Glenn et al., Monsanto is doing the same thing…25 years later.

Hopefully, all other developers of GE crop plants designed for human consumption: 1) know about this problem, and 2) are doing the same.

But Monsanto’s Selection Practices Were Not Always This Strict

Take selection criterion (ii) from Glenn et al., for example: to ensure “the intactness and integrity of the DNA insert.”  In the past, Monsanto Company has commercialized multiple GE corn varieties in which the intactness and integrity of the DNA insert was not maintained during the genetic engineering process; the DNA that ended up in the GE crop after the genetic engineering process was not the same as the DNA that was intended to be inserted.

And one of the best examples of a Monsanto GE corn variety in which the integrity of the DNA intended for insertion was not maintained in the final GE corn product is NK603. NK603 is the GE corn tested by Séralini and colleagues in a long-term rat-feeding study, a study that raised concerns–and subsequently controversy–regarding possible toxic effects of NK603 (and of glyphosate-containing herbicide) on animals (see, e.g., this article on the subject in Nature). NK603 GE corn was not only commercialized as an individual GE corn product; according to a report out of Purdue University, it also has been bred into at least half a dozen other GE corn products, some of which are associated with DowAgrosciences and Pioneer Hi-Bred as well as Monsanto.

The Lack of Integrity of the DNA Insert and Intended Gene Products in NK603

The integrity of the DNA inserted into NK603 was not maintained during the genetic engineering process used to create NK603. And that lack of integrity at the DNA level resulted in a lack of integrity of the RNA expressed from the inserted gene(s), and to lack of integrity in the form of a mutation in one of the foreign proteins produced in the GE corn varieties carrying the GE locus from NK603.

According to Monsanto, in addition to a single complete copy of the DNA the company intended to insert into the recipient corn plant (which comprises two versions of genes designed to convey resistance to the herbicide glyphosate), NK603 also includes an “inversely linked 217 bp piece of DNA containing a portion of the enhancer region of the rice actin promoter at the 3’ end of the inserted DNA.” This is another type of “extra DNA” that developers of GE crops do not intend to insert into GE crops: an extra copy of a random chunk of the DNA they do mean to insert, placed randomly adjacent to the intact complete copy of the DNA they do mean to insert.

And as a result of sequencing the inserted DNA to verify its “integrity” in NK603, Monsanto identified not only the extra, inverted piece of the rice gene promoter, but also two point mutations in one of the genes conveying glyphosate resistance, “one of which results in a change of the amino acid leucine to proline at position 214 in the protein.” The other point mutation did not change the amino acid sequence of this protein. Nevertheless, the integrity of the introduced foreign protein had not been maintained.

Additionally, and perhaps of most concern in terms of understanding how the lack of integrity of the DNA insert might affect the biology of the recipient corn plant, Monsanto scientists found that expression of the inserted gene(s) in NK603 produces an RNA transcript comprised of not just information stored in the inserted DNA but also information stored in the corn DNA adjacent to the position in the corn genome into which the insert was randomly placed. That is, “mRNA transcription was detected to initiate in either one of the two promoters of the NK603 insert and…continue into the corn genomic DNA.” RNA is an intermediary molecule that conveys the information stored in DNA to the cellular machinery; some RNAs translate the information coded in DNA into a protein that, in this case, provides resistance to glyphosate; other RNAs are now known to play roles in regulating how other genes are expressed. The upshot is that an unintended gene product, a chimeric RNA molecule comprised of intended insert-DNA-associated sequences plus sequences derived from the corn DNA that just happened to be adjacent to the spot in the corn genome where the foreign DNA insert landed, is produced in NK603 GE corn and any other GE corn varieties into which NK603 has been bred using traditional breeding methods.

More Safety Studies of NK603 are Needed

 We do not know whether the lack of integrity of the DNA inserted into NK603 results in any physiological changes in GE corn plants comprised of this GE corn event.

But we do know that if NK603 had been put through the procedures, checks and tests described in Glenn et al., it would have failed them.

In the meantime, we also know that Séralini and colleagues documented problems in rats fed NK603 over their lifetimes in a study that passed peer-review and was published in a reputable international journal (Food and Chemical Toxicology), but was retracted–more than a year after it had been in print–by the journal’s editor-in-chief after he deemed it “inconclusive.” We also now know that Monsanto played a behind-the-scenes role in the public attack on that study that resulted in its retraction.

What we need now is for that study to be replicated “by a truly independent laboratory using appropriate sample sizes” (David Spiegelhalter, a statistician at the University of Cambridge, UK). We need an update on NK603.

I, for one, would like to know–conclusively–the safety status of NK603 GE corn.

I would hope that the United States Food and Drug Administration, and its counterparts in other parts of the world, would want to know as well.


Posted in Biotechnology | Tagged , , , , , , , , , | 3 Comments