Independent Investigation into Claims
by Pro & Anti-GMO Groups
By Dr. Layla Parker-Katiraee
Dr. Layla Parker-Katiraee holds a PhD in Molecular Genetics from the University of Toronto and a Bachelor’s degree in biochemistry from the University of Western Ontario. She is currently a Senior Scientist in Product Development at a California human genetics biotech company. You can read her blog at frankenfoodfacts.blogspot.com, her LinkedIn profile or follow her on Twitter (@BioChicaGMO). All views and opinions expressed are her own.
The Innate Potato is a biotech or genetically modified crop that was recently approved1 for cultivation in the US. It was developed by J.R. Simplot Company, www.simplot.com. This article will review the potato in three sections: overview of the potato itself, summary of peer reviewed articles about the potato and my conclusion including whether I would consider buying it for my family.
The Innate Potato uses RNAi to silence four different proteins. RNAi2 is the same methodology used to make the non-browning Arctic Apple3. Very briefly, RNAi or RNA interference is a naturally occurring process in cells that can turn off or silence specific RNA molecules, and consequently, the proteins that they make.
In the past few decades, scientists have harnessed RNAi to turn off genes that they are studying. If you add a properly designed sequence of DNA corresponding to the gene you are interested in silencing, it will produce an RNA molecule that will trigger RNAi and then, wham! The protein gets shut down.
In the context of our discussion on the Innate Potato, it is important to note that a protein from a different organism has not been added. It is not like the mythical “fish genes in a tomato.”
The DNA sequence that was added is from the potato itself, which is why Simplot called it the Innate Potato4. Thus, it is not a ‘transgenic’5 crop, where the gene added is from a species distant to the potato. It is a cisgenic crop, where the genes came from closely related species; in this case, either from the potato itself or from a wild potato native to Mexico (Solanum verrucosum).
So what proteins are silenced in the Innate Potato and why? Four different proteins are silenced involving three different traits:
PREVENTION OF POTATO BRUISING (very similar to the non-browning Arctic Apple). Potato bruising6 is caused when damaged cells release an enzyme known as polyphenol oxidase (PPO), which interacts with different compounds creating the black or dark grey color. In the Innate Potato, the PPO enzyme is “turned off” only in the tuber but remains in the leaves7. Currently, many steps are taken in potato farming and handling to prevent bruising, but it does not seem to be enough. Potato bruising costs the industry at least $298 million annually8. Keep in mind that those bruised potatoes do not make their way to the store, translating into a lot of food waste.
- Simplot asserts9 that the potatoes will not turn brown for several days, compared to just 10 minutes with a normal potato.
- Reduction In Acrylamide Produced. Acrylamide is a chemical compound, which is also a known carcinogen at high doses. We use it in the lab fairly frequently. When I started doing lab work, I had the annoying task of making our acrylamide solutions, since I was the lowly undergrad. I took heavy precautions: a full mask, a full lab coat, etc. Once I got into my PhD, our lab had more funding, so we would buy the acrylamide solutions pre-dissolved. Now that I am in industry, we buy our acrylamide lab items ready-to-use. Such is the nuisance of acrylamide that no one wants to deal with it.So what is acrylamide doing in potatoes? When potatoes are heated, a chemical reaction, known as the Maillard reaction, occurs between asparagine, an amino acid and sugars such as the naturally occurring sugars in the potato.
When I was discussing this article with my spouse, he knew all about the Maillard reaction because it causes browning in food such as meats or bread. A Texan, he read about the Maillard reaction while doing research on how to cook the perfect steak.
Acrylamide also forms at high temperatures, such as when potatoes are fried in a fryer. In the Innate Potato, the amount of the enzyme that synthesizes asparagine is reduced; consequently, the result is less acrylamide. Simplot’s website claims10 that the Innate potato produces up to 70% less acrylamide than other potatoes cooked at the same temperature.
- STARCH QUALITY & POTATO COLOR IMPROVEMENTS. For information on this trait, I relied on information from a Q&A with one of Simplot’s VPs11 on Biofortified’s They reduced the amount of sugar in the potato, which can result in consistent golden color. Their website and the Q&A say “under certain conditions,” but do not explain those conditions in more detail.
In the first paper12, freely available via the company’s website, the authors attempt to silence two genes that synthesize the amino acid, asparagine. They had success in greenhouse trials, but to their surprise, the field trials failed: the potatoes were really small and cracked.
However, the ‘control’ potatoes grew fine, suggesting that it was not something environmental but rather the silencing of the two genes that caused these problems. They went on to do a series of experiments where they silenced the two genes individually. They produced potatoes with quality equivalent to the control potatoes but with reduced asparagine levels by silencing only one of the genes just in the potatoes, (scientists can often control what part of the plant in which they want to turn a gene off/on). They managed to reduce amounts of asparagine by 60-80%.
The second paper13 starts by outlining that the Russet Burbank strain of potato is more pest resistant, but is seldom used because it has issues with discoloration and sensitivity to bruising. Additionally, it accumulates high levels of sugar in cold storage, which not only result in higher levels of acrylamide, but also makes French fries less golden. The paper set out to address these issues by a.) reducing the levels of the enzyme that causes bruising (explained in the previous section), and b.) reducing the amounts of two enzymes associated with starch formation so that fried potatoes have a more appealing hue and have less acrylamide.
As a side note, this sentence in the Materials and Methods was somewhat hilarious: “Sensory evaluations of French fries were performed by a panel of eight professionally trained experts at the optimum time of three minutes out of the fryer.” Who is a professionally trained expert on French fries sensory evaluation? More importantly, how can I get that job?
The authors did a series of tests to confirm that the potatoes grown in the field actually had the physical traits they wanted. For example, when testing for bruising, they ‘physically impacted’ the potatoes and after two weeks, fries were made out of them to see if they blackened.
I would have LOVED to be a Grad student on that project. Imagine spending your time throwing around potatoes, all in the name of science!
The article included several pictures of French fries depicting the golden-hue of the modified potatoes. They also performed a few experiments showing that the modified potatoes kept their ‘agronomic performance’. When compared to the control potatoes, the modified potatoes were less susceptible to blight, were of similar sizing and had more starch content. Overall, the paper’s findings suggest that silencing of the three genes did not produce a negative impact and possessed all the desired traits.
I could not find any papers that convincingly indicated that there is enough acrylamide in fried potatoes to create a significant health concern. Additionally, no reputable organization states that acrylamide in food causes cancer in humans. National Cancer Institute lists information14 on the topic.
In fact, a few studies15 that examined the incidence of cancer and dietary acrylamide failed to find any association. Keep in mind that we eat natural toxins every day16, but not in amounts that are of concern. However, dietary acrylamide is enough of a concern to some people that all places that serve French fries in California have the ubiquitous (and therefore, useless) warning stating that the establishment has food known to the state of California to cause cancer or birth defects (i.e. Prop 6517). Therefore, it seems that this could be a potato of interest to the general public and the food industry.
Many of the usual arguments against GMOs do not hold for the Innate Potato. Here is why I think that the Innate Potato has less ‘GMOiness’ (and by GMOiness, I mean that subjective, intangible thing that makes people protest introduction of GMO into the marketplace):
- It does not need any additional pesticides or treatments.
- The sequence added is not from a virus or bacteria that cross the species barrier.
- It is not made by a company usually associated with GMOs, such as Monsanto or Dow Agro. Many oppose GMOs on the basis that they promote a monopoly for these companies; however, the Innate Potato is made by the J.R. Simplot Company and is the first genetically engineered crop developed by the company19 to gain commercial approval.
- It does not have the DNA sequence for antibiotic resistance.
- It addresses genuine health concerns that some may have (reducing acrylamide in our diet), as well as environmental concerns (reducing food waste).
Yet, despite the lack of GMOiness, the potato has been opposed by several anti-GMO groups.
To be honest, I am not terribly interested in the acrylamide reduction trait; because again, I have not read anything to suggest that acrylamide in our diet is at levels that cause harm. However, I would buy the Innate Potatoes if they are not much more expensive because they are less wasteful. I do think that the food industry should adopt them because they could make a genuine impact on reducing food waste from the farm to the store and because those ridiculous Prop 65 warnings annoy me.
I am also very curious to see how they are going to handle the labeling of the potato. The potato is designed to be nutritionally different from other potatoes, so it is not substantially equivalent. As you may know, the reason why genetically modified ingredients are not labeled in the United States is because they are nutritionally equivalent to their non-genetically modified counterparts, so it will be interesting to see how this plays out. Will they just list “Innate Potato” as an ingredient?
To learn more about the Innate Potato, please see this recent Q&A18 with a Regulatory Compliance Specialist from Simplot. Additionally, there is a lot of information about the potato and the science behind it is on Simplot’s website.
FOOTNOTE WEB LINKS