Apr 28 2009

GM Corn

Dr. Paul Christou and colleagues announced in the latest issue of PNAS that they have created a stable genetically modified (GM) version of South African white corn that has enhanced levels of three vitamins:

The transgenic kernels contained 169-fold the normal amount of β-carotene, 6-fold the normal amount of ascorbate, and double the normal amount of folate. Levels of engineered vitamins remained stable at least through to the T3 homozygous generation.

That’s precursors to vitamins A and C, and vitamin B9 respectively.  This is the first time a GM crop has been enhanced with more than one vitamin. The GM corn needs to go through the testing process, however, including animal testing for safety. It will likely be years before this corn is growing in the fields of sub-Saharan Africa – it’s intended target.

Of course – we’re talking about GM food, so there is going to be controversy. I will state my bias up front (i.e. what follows is purely my opinion) – I think genetic modification of crops is a perfectly reasonable technology. It is potentially a powerful tool, and like all the powerful tools science has placed in our hands, it needs to be used with caution. Of course there are risks – just as there are risks with piping explosive gas into our homes, operating nuclear power plants that can melt down, and speeding along highways at 60 mph where one mistake can mean death.

Also – like all such issues, there is hysteria and pseudoscience on both sides. Corporations likely have their eyes more on the potential profits than the potential risk and will tend to oversell claims. While the anti-GM food groups exaggerate risks and downplay benefits.  Somewhere in the middle there is a balance where GM foods can be beneficial, if used with caution. GM opponents serve a useful purpose in forcing governments and corporations to ask the tough questions and raise the bar on safety. But beyond a certain point they become obstructionist, needlessly hampering a useful new technology.


Genetically modifying food involves inserting genes into a plant or animal, typically to give them a trait they currently lack. This type of modification has been done to make crops droubt resistant or pest resistant, and has also been used to increase the nutritional content of food. There are also efforts underway to create a peanut that does not cause allergies. Here is a list of currently available GM crops.

Defenders of GM technology point out that modifying plants and animals by humans has been going on for thousands of years. Just about all the plants we grow and consume have been radically altered from their naturally evolved states. Plants in particular are amenable to hybridization, where genes from one related species can be combined with another.

The analogy is limited, however, because with modern GM technology genes can be taken from a bacteria and inserted into a grain crop.  This type of transfer is actually possible in nature – for example by viral vectors. But with GM technology gene transfer can be immediate and targeted.

Dr. Christou argues that his new GM corn is geared toward the malnourished in poor countries, where many people cannot afford a varied diet. In many parts of the third world people live on a limited number of staple grains, and lack variety in their diets. They are therefore susceptible to vitamin deficiencies. Therefore, enhancing the nutritional value of a staple crop could alleviate much malnutrition.

In Asia, for example, blindness from vitamin A deficiency is common. This has led to the development of so-called golden rice, which has enhanced levels of beta-carotene. Rice can already produce beta-carotene, but only in the husk, not in the consumed part of the rice. By inserting three genes into white rice scientists have turned on the beta-carotene production in the rice grain istelf, giving the rice a golden color.

GM Critics

In the BBC article discussing this new corn, Clare Oxborrow from Friend of the Earth is quoted as the GM skeptic.  It’s important to note that such articles rarely do justice to a person’s complex position, but with that caveat she does raise the typical concerns over GM crops.

Ms Oxborrow said it was “virtually impossible” to contain GM crops and to be sure that all the people eating them were getting the correct dose of what they had been modified to make.

The primary argument of opponents to GM crops is that they are too risky becauses it is impossible to contain them. The new genes they contain may contaminate other crops or wild plants, with unintended consequences. This is a legitimate concern, although it is not clear how much of a risk this really poses. For genes that confer resistance to pests or herbicides I can see why this would be a real concern – we do not want to create super weeds. But for genes that enhance nutritional content it seems that the risk would be quite low. What is the risk from nutritionally-enahanced weeds?

Theoretical risks revolve around unintended consequences, such as creating a crop that has more potential to induce allergies, or affecting the natural food chain. What will the effect be on the animals who eat the weeds that are now modified by GM genes? I think these are good questions, but to me they equal proceeding with caution, not abandoning GM technology.

Oxborrow also plays down the potential benefits of GM crops:

Rather than opt for “expensive, untested and potentially risky GM technofixes”, she said “research efforts would be better placed ensuring that people are able to grow, or otherwise have access to, a diverse range of foods that will give many other health benefits.”

Ms Oxborrow said golden rice, fortified with vitamin A, had been available for many years but was still not widely used or commercialised.

This is a good example of the perfect being the enemy of the good. Sure, wouldn’t it be great if the entire world had access to the variety of food we enjoy in the US and other industrialized nations.  And of course there should be efforts to improve food availability in the third world. But let’s be realistic – there are real-world economical, political, and logistical reasons why there are still billions of people with inadequate access to nutrition in the world, and no one is going to solve these complex problems anytime soon. Nutritionally enhanced staple crops is a partial fix only, but it can significantly improve the situation and reduce diseases of nutritional deficiency that place an even further burden on poor countries.

There are also obstacles to implementing the use of GM crops, such as golden rice. I am actually not sure why it has not been more widely adopted. Perhaps it is resistance to GM foods or the slowness of regulatory agencies. GM critics argue it is simply the greed of corporations, who create GM foods primarily to maintain their monopoly. There is probably some truth to all of these claims, but I have not found a convincingly definitive answer (and would welcome any informative links).

Of note, the Golden Rice Humanitarian Board claims that:

Those who need the product of this new technology most are those who can least afford buying a mixed diet, rich in essential nutrients. This has been taken into consideration by the creators of Golden Rice technology, Professors Peter Beyer and Ingo Portrykus, and the crop protection company Syngenta, who have donated it for humanitarian use in developing countries, free of charge.

Also, Dr. Christou claims:

Dr Christou told BBC News: “Our research is humanitarian in nature and targets impoverished people in developing countries. This specific project is targeted towards sub-Saharan Africa.”

He added: “Our funding is exclusively from public sources so we are not encumbered by any commercial constraints.”

A cynic could argue that this is PR by an industry with a troubled reputation.  Perhaps, but human behavior is rarely one-dimensional. Most corporations engage in charity for the PR benefit, but the people in those corporations also probably have charities they really care about and want to think of themselves as good people and good corporate citizens.

So let the GM food industry engage in a little humanitarian aid, putting their technology primarily to the purpose of enhancing the nutrition of the poor.


The GM controversy is one of those heated topics that I find very challenging to completely wrap my head around. Like recycling, organic farming, and even global warming – the science is complex, the claims made on both sides are complex, and the vast majority of information available to a non-expert like myself seems tainted by bias. I find it hard to get to the bottom.

In the case of GM food I think part of the reason for this is that there really are legitimate points on both side of the issue. Perhaps the risk/benefit is close to the line. Perhaps the technology has not yet advanced enough for the benefits to clearly outweigh the risks or expense.

But I find the concept of GM food to be reasonable, and many of the products that are already on the market seem to have clear advantages and to be commercially viable. This technology has great potential.  I also find that many of the arguments against GM food are ultimately rooted in a visceral reaction against anything artificial or corporate. I find their arguments less compelling and logical. For example, arguing that a more nutritious variety of corn is not a good thing, as Ms. Oxborrow did, seems like ideological advocacy to me and not a reasoned position.

But I acknowledge that my current position on this topic is tentative pending further exploration of the issue.

33 responses so far