[ health ] :: what does GMO really mean?

It seems that more food manufacturers are beginning to go above-and-beyond the norm when providing information labels to their consumers. As someone who tries to routinely shop for healthier options, I love that more companies are becoming aware of the wants of consumers like myself. I've also noticed that more companies are labeling their "non-GMO" foods, and it seems that "GMO" food is becoming a hotter topic every day. Sadly, it seems that many people don't know what "GMO" means - is it a chemical? An additive? How "bad" is it for you?

A few nights ago, The Hubs and I were having a rousing conversation before bed about artificial selection versus natural selection (we are huge, huge dorks) and he said something about genetically modifying organisms. This is where I went all biology-instructor on him and gave him a good schooling on GMO's. (And he actually listened...)

To put it simply, "GMO" stands for Genetically Modified Organism (for now, the organisms being commercially sold are food crops like corn, soybeans, tomatoes, and canola). While the process may seem daunting, GMO's have been developed by introducing specifically planned changes into their genetic code: the DNA. Why would people do this? Well, for starters it allows scientists to instill characteristics that that plant would not naturally have, such as additional nutrients and resistance to pests or disease.

One highly beneficial GMO food, Golden Rice, was developed and released in 2000. Us older folks may have heard about it on the news. Scientists developed a type of rice that is higher in beta-carotene (provitamin A), the nutrient that gives fruits and vegetables their orange/yellow color. More importantly, the body converts it to Vitamin A where it is used for many important physiological functions (for example: eyesight). For that reason, a Vitamin A deficiency can be fatal, especially in children. The Golden Rice Project began as a humanitarian effort to make this GMO food available to people in countries where Vitamin A deficiency was prevalent.

From the Golden Rice Project website: 

"In Golden Rice two genes have been inserted into the rice genome by genetic engineering, to restart the carotenoid biosynthetic pathway leading to the production and accumulation of β-carotene in the grains. ... Our goal is to provide the recommended daily allowance of vitamin A in 100-200g of β-carotene-containing rice. This corresponds to the amount of rice eaten daily by children living in rice-based societies, such as India, Vietnam or Bangladesh. In other countries, Golden Rice could still be a valuable complement to children's diets, thus contributing to the reduction of clinical and sub-clinical vitamin A deficiency-related diseases.

According to the World Health Organization, dietary vitamin A deficiency (VAD) causes some 250,000 to 500,000 children to go blind each year. Blindness and corneal afflictions are but indicators of more severe underlying health problems: more than half the children who lose their sight because of VAD die within a year of becoming blind. VAD compromises the immune systems of approximately 40 percent of children under the age of five in the developing world, greatly increasing the risk of severe illnesses from common childhood infections."

Normal rice versus Golden Rice. Unlike the "yellow rice" you get at the grocery store, which is colored with spices and food dyes, Golden Rice gets its color from the beta-carotene it produces on its own. Picture c/o The Golden Rice Project.

In my opinion: GMO's for the win! However, there is still much controversy over GMO-containing foods...and concerns, for good reason. 

The first argument in opposition to GMO food are the health concerns. For example, if a vegetable is genetically modified to be resistant to disease or insects, is there any toxic effect? An example that sticks out in my mind is the 2010 controversy over Montsano's genetically modified corn (check out the news stories here and here). To summarize, evidence showed that there were long-lasting effects in animals that consumed the corn, such as kidney failure and disruption in normal hormones. 

Other concerns that have been voiced pertain to gene transfer. What does this mean? In gene transfer, the genetically modified material from the food that an animal eats could be transferred to the animal that eats it (such as livestock animals and humans). A review paper in 2012, 'Ingested plant miRNAs regulate gene expression in animals,' summarized recent findings in this area of research. It concluded that RNA consumed from genetically modified plants modified the expression of genes in the animal who ate them. Scary stuff.

Finally, a common question that has been posed is, "what if genetically modified organisms are able to cross-breed with other organisms?" Hypothetically, a genetically modified crop that is resistant to herbicides could be produced. The crops could be sprayed with weed-killer, but would not be harmed. That same crop could breed with another non-genetically modified crop - then your non-GMO or organically labeled food would not be truly labeled correctly. In another situation, a type of grass could be produced that is resistant to weed-killer (and it actually already has). What if the grass pollen was able to fertilize a genetically-related species? There is a large concern over this, as it could create species of weeds or other herbaceous pests that are resistant to pesticide. Think kudzu, but worse (people in Georgia know exactly what I'm talking about!).

So now that you're a tiny bit terrified, I'll give you one last example of genetically modified organisms, but one that have saved millions of lives: bacteria. I was sent this picture from a student when we had a discussion on diabetes. It depicts the process involved in making insulin for diabetic patients, and is a great representation of how GMO's are made.

First, a strand of DNA is isolated that codes for the protein or trait that will be produced. In this case, insulin is to be made so the gene that codes for DNA is cut out of an insulin-producing cell's DNA (it's easier than it sounds!). Then, that DNA is inserted into a plasmid - a small, circular piece of DNA taken from bacteria or is synthetically made. Bacteria just love to collect these plasmids and start copying the new DNA. The special thing about this is that the bacteria not only copy the DNA plasmid, they also make the protein it codes for! Here, the bacterium is making human insulin. In 24-28 hours, scientists can isolate and harvest the insulin. Pretty nifty, right?

Hopefully this got you thinking - are all genetically modified organisms "bad?" Would you mind using them to save lives, such as in nutrient deficiencies or insulin production? Would you want to eat them? Where do we draw the line?

That concludes our discussion on GMO's - class dismissed!

- Maggie White