Genetically Modified Foods

Can I buy (GM) golden rice? I have looked for it and have not been able to find it.

-A curious adult from California

November 5, 2009

I've looked and looked too and I can't find any place where you can buy golden rice. Which isn't surprising since farmers are forbidden from growing it pretty much anywhere on the planet.

Golden rice was created as a way to combat vitamin A deficiency in the developing world. The numbers I have seen for this problem are truly horrifying. It is responsible for 1-2 million deaths per year and over 500,000 cases of irreversible blindness.

Red, orange and yellow areas show where vitamin A deficiency is a problem.

Vitamin A deficiency often happens to people who lack a varied diet and eat mostly rice. So scientists genetically modified rice to turn it from a poor source of vitamin A into a good one. The end result was golden rice.

Since this rice is a genetically modified (GM) food, it was immediately in the sights of lots of protest groups. And has been there ever since.

These groups have used many different legal means to delay its planting and harvesting. If golden rice can actually do what researchers claim, then millions of people are blind or dead because of the delays.

Of course this is a big if. These groups are concerned that golden rice may prove more dangerous than the problem it is meant to solve. In which case their delays have protected people and the environment from something worse than these millions of deaths.

What I thought I'd do is go over some of what we know and don't know about golden rice. I want to say upfront that I don't necessarily have all the answers here. I will just talk about what I consider three key points in whether golden rice should be used:

  1. Is it safe?
  2. Will it be effective?
  3. Are there alternatives in the near term?

Before getting into these points, I think it is important to go over how scientists made golden rice in the first place. As you'll see, they've essentially turned on a process that works in other parts of the rice plant.

Making Golden Rice

Plants don't make vitamin A. Instead, they make beta carotene which our bodies convert into vitamin A. And rice is no different.

The only problem for us is that rice doesn't make beta carotene in the part of the plant we eat. Which is why scientists set out to make golden rice.

This wasn't easy. It takes a lot of genes to make beta carotene and if any one of these genes doesn't work, then no beta carotene gets made.

When scientists looked at rice, they found that rice didn't make beta carotene in the rice kernel because many key genes were off there. They decided to add back genes to get the process working in this part of the rice plant. Sort of like gene therapy for the rice plant.

In the latest version of golden rice, scientists connected a corn gene and a bacterial gene to a piece of DNA that keeps these genes turned on in the kernel. The scientists then got these genes into the rice using a plant virus.

Is it Safe?

We need to split up the safety concerns into two broad categories. One has to do with eating the stuff. The other has to do with what this rice will do to the environment.

First off, there is nothing dangerous about the DNA per se. We eat DNA everyday and it all gets digested and used for energy or to build up our own DNA. Eating golden rice isn't any worse than eating rice and corn from a DNA perspective*.

There is a slim chance that someone who is allergic to corn might be allergic to this rice too. This would only happen if someone happens to be allergic to corn because of that certain gene.

This is extremely unlikely but has happened in the past with Brazil nut genes and soybeans. Presumably this will be tested for and anyone who is allergic can pretty easily avoid this rice. If you're allergic, treat rice like snow" and avoid the yellow stuff.

Another possible danger is that people may get too much vitamin A from golden rice. We know that too much vitamin A can cause problems like birth defects and osteoporosis.

But these things happen if you get too much preformed vitamin A that comes from supplements or some meats. I haven't seen any studies that say that too much beta carotene is toxic. The body uses what it needs and excretes most of the rest. (Sometimes with way too much beta carotene people can end up with an orangish color to their skin but no one has shown that this has any adverse health effects.)

So it is extremely unlikely that people will overdose on golden rice. In fact, I'll talk about a more legitimate concern about people not getting enough vitamin A from golden rice in the next section.

Another danger people mention is that you don't know what subtle effects adding these two genes might have on the rice. Perhaps the rice will make something we don't expect and haven't been looking for that is dangerous to human health.

I think at this point it is important to mention that this theoretical possibility is extremely unlikely. And that as I wrote this last week, another 42,000 people died because they didn't get enough vitamin A.

I'm not saying we should just throw it into the population and see what happens. Good animal studies should be done ASAP to test how safe golden rice is.

Of course these animal tests have to be meaningful to be useful. If they are done right, we have to take the results at face value. We can't have people cherry picking the results that fit with their own bias. Or demanding animal studies but then discounting them if the animals are not harmed by the rice.

The other major safety concerns are environmental. I don't mean that the rice itself will take over the valleys of China or Bangladesh. This isn't very likely at all.

The major concern seems to be that the DNA will move into wild strains of rice. Or that it will leap to different species altogether. The fear then is that two genes that are involved in making beta carotene in the endosperm of rice could move into these plants.

Even if this happened, it wouldn't create a superweed like with some RoundUp ready plants. Basically plants that happen not to make beta carotene for the same reason that rice doesn't in its kernel might start to make beta carotene. Not very scary as far as I can tell especially when compared to millions of deaths.

Will it be Effective?

This is obviously a key question. As we've talked about, the risks are pretty minor with golden rice. But if it doesn't do any good, then even these unlikely risks won't be worth it.

So, can our bodies convert the beta carotene into vitamin A? Can we get enough vitamin A to make a difference? Is the gene stable enough so the plants will keep making beta carotene?

The first golden rice definitely didn't make enough beta carotene to have much of an effect. It was estimated that you'd have to eat at least five pounds of this rice every day to get enough vitamin A. Needless to say, Greenpeace had a field day with the photo they generated from this statistic.

This first version of golden rice had a daffodil and a bacterial gene. In the second version, scientists replaced the daffodil gene with one from corn. Now golden rice makes plenty of beta carotene.

But can our bodies use it? A new study out says that they can. And that they can get enough vitamin A to make a real difference. In the study, people were fed 200 grams (about 7 ounces) of steamed golden rice and then they had their vitamin A levels checked. What the researchers found was that the study subjects got 80-100% of their estimated average requirement of vitamin A (or 55-70% of their recommended daily allowance).

This sounds great although there is a potential problem with the study. The subjects had their rice with about ¾ of a tablespoon of butter. They also got a lunch 4 hours later that was about 40% fat.

I don't know for certain but this seems like more fat than the average vitamin A deficient person would have in their diet. And this is important because beta carotene is only used efficiently in the body if there is some fat around.

The other issue I see with golden rice in general is whether or not the program can be self-sustaining. To really work and help these people, golden rice should stay golden over many generations. That way people can replant using their own seeds and they don't have to rely on their governments' shaky distribution system to get new seeds.

This is an issue because sometimes when a foreign gene is put into a plant (or any cell really), it is kicked back out again. Or shut off.

This could happen with golden rice too. It might lose its ability to make beta carotene over time. Then the farmers will have regular old rice again and vitamin A deficiency would come roaring back.

Scientists need to make sure that the gene is stable and stays on. At the very least it should keep working in a high percentage of the plant.

Are There Alternatives in the Near Term?

I've spent some time looking and I haven't found any good ones. Distributing vitamin supplements or giving people shots would probably work best but a lot of these countries are not particularly well run. Remember the cyclone in Bangladesh?

Some people suggest that eating the whole rice (brown rice) might be better. And it is for lots of vitamins. There just doesn't seem to be much beta carotene in there. Brown rice also goes bad pretty easily so storage can be a problem.

A varied diet has also been proposed which would be great. Except that a lot of these people are too poor to eat anything but rice. Which is why golden rice was created in the first place.

Hopefully some good animal studies will be done and the diet study will be redone with less fat. If each of these studies works out, then maybe you can go to your local grocer and buy some golden rice. I wonder what it tastes like?

*Others argue that some of the DNA is different and may increase the amount of antibiotic resistance in the world. Studies do not support this claim.

By Dr. Barry Starr, Stanford University

Scientists used plant gene therapy to make rice a good source of vitamin A.

DNA is safe to eat. You probably had some for breakfast.











Golden rice is a good source of vitamin A just like these carrots.