I originally discussed the need for nutrition professionals to enter the genetic engineering (GE) conversation/GMO debates on the American Society for Nutrition’s (ASN) blog. Neither the Academy of Nutrition and Dietetics (AND) nor ASN has an official position stance on the science, safety and application of GE foods. I find it highly problematic that these major nutrition professional bodies have not provided any guidance on this controversial issue for their constituents and, ultimately, the public. Call me crazy, but one might think that a professional body representing nutrition might engage in a controversial discussion regarding food... With their absence, I have seen many representing the broader nutrition field and spreading fear about genetic engineering, hardly from an evidence-based perspective. I discussed some general ways to approach genetic engineering, touching on problems related to overly broad conversations, safety and corporations, in part one of this series. But for this second part, I wanted to do what professional nutrition organizations have remained oddly silent on: discuss how we can leverage genetic engineering for better health, nutrition and research.
Below, I’ll address a number of ways that we can use GE to address real issues in the world, and make our food a bit better. Unfortunately, many of these examples still represent ‘potential’ solutions, because the current regulatory system has not encouraged public sector scientists to widely invest in this technology (why develop a genetically engineered food if it’s going to take years and millions of dollars to get it to the people who need it?). Despite having a regulatory system that doesn’t encourage new development, we still find a number of examples in the research of ways that GE could substantially improve the food supply. I don’t claim that any of these examples are ready for market immediately (remember: it took a couple versions of Golden Rice to get it right), but rather, they serve as ‘proof of concept’ studies, suggesting that nutrition professionals should get more interested in this technology, and encourage a political/regulatory system (and more importantly, a public) that allows for the tools of genetic engineering to be applied to our food, beyond just traits that benefit farmers. Let’s look at some examples:
1. Allergens - Many of the arguments lodged against GMOs rest on the idea that they could possibly introduce new allergens. This, however, is a purely theoretical risk, not unique to the process of genetic engineering (all known allergens were created long before genetic engineering), and is something that producers of GMOs do their best to make sure doesn't happen (something that doesn't happen for traditionally bred products before they enter the market). A concrete benefit, as opposed to the theoretical risk of GE, is that we can create hypoallergenic and potentially allergen free crops. This was first applied to dietary allergens in rice - scientists used antisense gene technology to down-regulate the expression of alpha-amylase-like proteins (common allergens in rice). Other researchers have combined transgenics and naturally occurring mutants to produce strains of soy that exhibit high tolerability by soy sensitive individuals. Since these older papers, RNA interference (RNAi) has emerged, having great potential to knockdown the expression of multi-gene families. So far, this has been applied to peanuts, wheat , tomatoes, and cow’s milk. These are preliminary studies and could likely be applied to other common foods. Talk to any pediatric dietitian about the problems that dietary allergens present for those susceptible children, and it’ll be hard not to get excited about the idea of hypoallergenic/allergen free crops.
2. Food Waste - Many in the food, ag, and nutrition fields will know that food waste is a big issue, especially here in America. In 2013, it's estimated that we threw away 35 million tons of food. Both food lost at the level of industry and the consumer are contributing to this issue. Among the many issues that contributes to consumer and industry food waste is damaged/bruised produce. The innate potato was developed using RNAi to knockdown polyphenol oxidase, the enzyme responsible for enzymatic browning; the potato bruises less easily, while also containing less reducing sugars (industry buyers often reject potatoes that have too high a level). Biofortified had a great interview with their president here, and he discusses the benefits of the potato, including the potential food waste benefits. Enzymatic browning is an issue that affects a number of food crops, opening the doors for broader applications of this technology. Significant portions of fruit and vegetable crops are thought to be lost to post-harvest browning, representing a unique situation where genetic engineering could reduce food waste.
3. Nutrients - Many lodge critiques against nutrient biofortified crops because they feel that poverty is the true cause of nutrient deficiencies. While this has some truth to it, it doesn't prohibit nutrient-enriched crops from addressing some of these issues. As I've talked about previously, deconstructing arguments against Golden Rice, HarvestPlus and its research collaborators are publishing a number of trials of (non-GE) biofortified crops, and showing their efficacy in improving nutrient status. While these crops have generally been applied abroad, they could have an impact in America as well. With growing concerns of the environmental impacts of high meat diets, and potentially detrimental health impacts of high red meat diets, alternative sources of critical nutrients, particularly from animal foods, like iron and zinc, could aid in nutritional woes about reducing our consumption of these foods. Biofortified crops, through traditional breeding and genetic engineering, could serve as these alternative sources. To list just a few of the ways genetic engineering has affected nutrient status in one way or another:
- Manipulation of the fatty acid profiles of many oils (higher oleic oils to replace trans fats, working on getting LongChain n-3 PUFAs from plants, reduction of saturated fatty acids, etc)
- Folate tomatoes - less than a serving of these reach the RDA
- Cow’s milk high in lactoferrin - studied for its benefits on the microbiome
- In addition to plants, a number of methods for animal modification have been suggested to alter the lean mean content of animal foods, as well as the fatty acid profile.
Increasingly, the technology has been used to address increasing non-essential nutrients. Tomatoes have been the model for this, with multiple groups affecting flavonol and anthocyanins (similar to what you find in some berries); this might not only be good for health, but also for the shelf-life of the tomato (back to some potential food waste benefits). Lettuce, as well as apples, has been modified to produce resveratrol contents similar to that in grapes.
4. Research - The notion that we can alter the non-essential nutrient composition of foods particularly interests me. We can sit here and say ‘oh look, more resveratrol’, but what does that tangibly mean? There is long standing debate in nutrition about these non-essential food components, their health benefits, and the doses needed to achieve the former. Scientists can isolate these compounds, feed them to a human/animal, and try to draw conclusions based off of these results. Often, these doses are higher than one could achieve with a food, and/or fail to explain the results of some association found in an epidemiological cohort. For example, isolating lycopene and feeding it to people doesn’t fully explain the ‘observed’ association between a lower risk of prostate cancer and tomato consumption. While some may use the isolated lycopene data to say this association was a fluke, others retort with saying that removing lycopene from the rest of the tomato food matrix removed pertinent interactions. Who is right? This is another area where genetic engineering could provide some clarity: we could use GE to create seemingly innumerable varieties of crops with higher/lower levels of specific compounds, and utilize them in whole-food feeding studies (and hey, if it works out, maybe commercialize them). There are examples of this already occuring, coming from both the molecular breeding and transgenic worlds - Monsanto's created the (non-GE) high glucophoranin Beneforte broccoli, and the transgenic, high anthocyanin tomatoes mentioned above (there’s some interesting animal experiments look at the effects of these tomatoes on cancer). (Note: I'm aware that many of the phytochemical concentrations are also affected by the environment). As someone interested in phytochemicals, but frustrated that most of our data comes from epidemiological associations (highly confounded by all of the other things in food, and the lifestyles of those who eat high fruit/veggie diets), the use of these technologies to create not only better food but improve our understanding of the food matrix excites me.
5. Sustainability - There are seemingly innumerable ways in which genetic engineering could benefit sustainability.
- The benefits of reduced food waste noted above fall under this category.
- The EnviroPig: this pig is engineered to produce phytase, enhancing its ability to extract phosphorus from foods, and reduces phosphorus inputs - excess/excreted phosphorus leaching into water supplies is a large environmental concern.
- With the over-farming of wild fish, there's an increased need for alternatives sources of omega 3 fatty acids - genetic engineering can not only provide sustainable sources of these for farmed fish/animals, but as mentioned above, GE can overcome the natural limitations that prevent plants from synthesizing their own long chain omega 3 PUFAs (whether these methods will allow for n-3’s at biologically relevant values remains to be seen).
- Of course, there are the much touted (and hotly debated) benefits for yield increase, chemical input reduction and preservation of biodiversity, all ideal characteristics of a sustainable agricultural system.
These are just a few examples of the benefits that GE can/could have for sustainability folks - as nutrition and sustainability become more intertwined, nutritional scientists and clinicians will likely seek out food crops not only for their nutritional benefits but environmental ones as one. For those interested, Pam Ronald wrote a great publications, with numerous other examples (like improved nitrogen efficiency and drought resistance) of sustainability and GE here.
6. Improved Animal Welfare - Animal welfare is increasingly a concern voiced by nutrition professionals. Genetic engineering boasts a number of ways in which it can improve animal health and welfare. One area that has received much interest from scientists is in disease resistance. Mastitis, an infection of the mammary gland, is a common infection affecting dairy cows, leading scientists to develop a transgenic cow that creates lysostaphin, a protein that confers resistance to the Staph. aureus that causes the infection. This is just the tip of the iceberg and a simple example of how disease resistance can be engineered into animals. A more recent advance in animal welfare that caught my attention was hornless cows. Anyone who has watched a PETAvideo has likely seen a clip of cows being de-horned. Cows that don't grow horns to begin with, a process achieved with newer gene editing techniques, bypasses this controversial animal rights issue altogether. You can read all about transgenic animals, including a discussion on animal welfare, here.
7. Flavor - Food technology has afforded Americans one of the best tasting food supplies - flavor chemistry is indeed,an awesome science. But the foods that taste the best, aren’t always those that benefit our health - indeed, there’s a popular book about this topic called “The Dorito Effect”. One of the areas of plant breeding and applications of genetic engineering that I find most promising is the manipulation of flavor profiles of common foods, particularly fruits and vegetables (some in the literature have suggested that traditional plant breeding for yield has come with some flavor trade offs). When it comes to examples of GE and flavor enhancement, tomatoes seem to be everyone’s favorite model. A 2007 study in Nature Biotechnology demonstrated that introduction of the geraniol synthase gene in tomatoes improved taste for consumers - while this reduced lycopene accumulation, it added other terpenes that have been studied for their antioxidant properties (this dually gets at my research point above - what do these terpenes functionally mean?!). A group from Kansas food scientists performed a consumer sensory analysis of their transgenic high flavanoid/anthocyanin tomatoes and found that, on average, the panel rated the transgenic tomatoes higher than the wild type. Harry Klee, a molecular horticulturalist at the University of Florida, has pioneered the use of molecular assisted breeding to make a better, more flavorful tomato. SciMag covered the issue here. Note his answer when asked about tomatoes and GM:
While most in nutrition can all rally around tastier fruits and vegetables, especially if kids are more willing to eat them (one of the benefits touted for GE non-browning apples is that kids prefer pre-cut fruits), scientists have gone on to plan magnanimous feats with genetic engineering, discussing the ways that genetically engineered yeasts can improve the flavors of wine and beer.
8. Food Safety - An example that more recently came to my attention was the potential for improving food safety. There are a number of very hypothetical ways that I could imagine this (one could argue that making animals resistant to certain bacteria would), but a more concrete examples shows up with Bt corn and mycotoxins. Bt corn shows lower levels of aflotoxin and fumonisins, two toxins linked to cancers in animal models, and to both cancer and neural tube defects in humans. More on the issue is discussed here.
8. Food Safety - An example that more recently came to my attention was the potential for improving food safety. There are a number of very hypothetical ways that I could imagine this (one could argue that making animals resistant to certain bacteria would), but a more concrete examples shows up with Bt corn and mycotoxins. Bt corn shows lower levels of aflotoxin and fumonisins, two toxins linked to cancers in animal models, and to both cancer and neural tube defects in humans. More on the issue is discussed here.
I hope that I’ve convinced you that genetic engineering is something that nutrition professionals should be concerned with. I encourage any who are interested to read further about this topic, and encourage professional bodies to take a stand on the issue. The Academy of Nutrition and Dietetics has been struggling to discuss this topic and have any official stance on it, due to some internal discord. It’d be nice to see more support from within and outside the AND (this goes for ASN too) to publish a position on the use of GE and guidance for future research. Too long has this conversation been occurring without the voice of nutrition professionals, when we, and consumers of food, have much to gain from the application of GE. Overall, we all need to be supporting a regulatory environment that aims to facilitate more than just larger companies to develop genetically engineered crops, and one that doesn't unnecessarily regulate one type of breeding method over another, without evidence to do so.
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