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Time out for science: genetically modified food/GMOs

Wednesday, January 09, 2013

Well hi.

BROOKLYN BORN's blog got me thinking about GMOs, again.

I have done a lot of reading about this over the years, because I'm a science minded person and I like to know things.

Full disclosure: I am not an agricultural scientist or a food scientist or anything. But I did double major in biology and chemistry, and I did take botany, I did take cellular biology, and I did go to graduate school and spend many years training on 1) how to do a well controlled scientific study and 2) how to read scientific papers and evaluate their methods and conclusions. So I feel pretty confident about this.

Also, if you have met me you don't really need this warning, but I'll say it anyway. This is probably going to be LONG.

Okay, so GMOs. That stands for Genetically Modified Organism. I am not being sarcastic, just making sure everyone knows that, so you know what we are talking about in case all you knew before was that it stands for Scary Food Things.

What does this mean?

Using the science of genetics to change the genes and/or characteristics of an organism.

Genetics deals with the structure of genes (how they are arranged, what they are made of) and their function (what they do in a living organism).

Let's do a Zoom In:

First we have you. You have a body. It is made of different organs, which are made of different kinds of tissue, which are each made of lots of cells.

For example, you have muscles, which are made of muscle cells, and you have red blood cells in your bloodstream, and both muscle cells and other types of cells, like the ones that secrete acid, in your stomach.

Each of your cells has a nucleus, like a little baggie full of DNA in the middle. Your DNA is divided into multiple little blobs, called chromosomes, and each chromosome is a long strand all balled up. The strand is made up of a bunch of genes. A gene is basically a piece of DNA that has a specific job, which we know what it does. Seriously. You have a lot of DNA that ISN'T part of a gene that currently is defined and has a name, but science doesn't know what those parts for.

So somewhere, on one of my chromosomes, is a piece of DNA. When the cells in the hair follicles in my scalp unwind that clump of DNA, and attach an enzyme to it, that enzyme gets "turned on", like a switch turning on a little machine. That enzyme will attach to some other molecules, somewhere, and when all the little chemicals inside the cell that have been activated by that gene have done their job, they will have included a bunch of melanin (pigment) in with the keratin that makes my hair. Which makes my hair brown. That's how genes work. Other chemicals in the cell "read" them, and they do a job. This gene's job is to make my hair brown. If you have blonde or red hair, you have a slightly different gene in that spot on YOUR chromosome, so your little cellular machinery puts less pigment, or different pigment, into your hair as it grows.

Other genes do other things, obviously, and some are much more complicated.

But let's extend this example to plants: Red Delicious apple trees must have a gene somewhere that puts red pigments in the skin of the apple as it grows and ripens. Golden Delicious either 1) have a different gene, either one for "put yellow" or one for "don't put red" or 2) their copy of that gene for "put red in the skin" doesn't work. Human beings created these varieties of apples by hybridizing plants - we found a tree with yellow apples, and said "cool, yellow apples!", so we used the pollen from that tree to fertilize the flowers of a tree with sweet apples, and tried this a bunch of times, and eventually grew trees with sweet yellow apples.

If you ever bred dogs or known anyone who has, this is also similar. Dalmatians were "genetically modified" from dogs that weren't white or didn't have spots, by only letting dogs who were white and had spots have babies together, for decades, until you could always breed a dalmatian and a dalmatian and get more dalmatians.

In the modern, in-a-lab kind of genetic modification, there are different ways of mixing genes besides taking two parents and creating offspring and crossing your fingers HOPING the babies have the characteristics you want.

But here's the thing: It doesn't really matter HOW the new genes got in there. The result is the same.

What if we genetically modified a seed from a red delicious apple so that it was the same except we took out or changed the "put red in the skin" gene? Once you plant the seed, and tree grows, and produces sweet yellow apples, the result is the same as the "natural" golden delicious apple: an apple with a gene for "don't put red in the skin."

What happens in your stomach when you eat a red delicious apple? I mean, specifically, what happens to the red delicious apple's GENES?

Remember, genes are pieces of DNA. DNA looks like this:

The dark blue parts represent sugar molecules. The light blue parts are another kind of molecule, a phosphate. And the parts that look like puzzle pieces represent nucleotide bases - adenosine, cytosine, guanine, and thymine. For shorthand we usually just call them A, C, G, and T.

These bases are key. They are how DNA tells all the little chemicals in the cell what to do. When that enzyme that is helping to build my hair is sliding along the DNA, it can only "stick" or connect with a certain shape that matches its shape. A, C, G, and T are shaped differently! so, in the same way, a strand that has AAA in a row, and one that has ATT in a row, are going to be shaped differently. "Put brown in the hair" will only happen if the right sequence of letters for the "put brown in" enzyme is there on the DNA for it to stick to and get switched on.

When we "read" a molecule of DNA, we usually just "read" one side, so let's look at the upper right piece there.

See the key that tells which puzzle color is which letter? That piece, from the top down, is T G T C C.

What does your digestive system and body do with that?

It will break open the cells of the apple. It will break up all the sugars and protein in the apple into smaller sugar molecules, and amino acids (what protein is made of) and send those molecules wherever it needs them.

The DNA will be unwound and then broken up. So you'll have dark blue, light blue, red, pink, green, and yellow bits. All those pieces. Like puzzle pieces! And your body will use them to make new DNA wherever it needs it. Let's say you have a cut that's healing. Your skin cells are dividing to make more skin cells. When your cell divides to make 2, it has to copy its DNA. So your body will use those A C T and G puzzle pieces to make a copy of YOUR DNA to keep in the new cell.

Do you think your body "remembers" or cares where those puzzle pieces came from?

It doesn't. It doesn't matter if that T came from a gene in an apple, or a random non gene end piece of DNA from a bit of chicken you ate for lunch with the apple.

What about our GMO yellow apple?

Let's say T G T C C on the upper right there represents the "put red in the skin" gene. (Genes are MUCH longer than five bases, but let's pretend for simplicity's sake) How did we make our GMO apple? We change that gene so instead of telling the cells "put red in the skin" it tells them "don't put red in the skin." Let's say I changed it to T A T G G.

What happens when you eat THAT apple?

Same thing, your body breaks it up and uses all the puzzle pieces. I know, you're thinking "WELL NOW I DON'T HAVE ANY Cs, GREAT!" but remember this gene would actually be thousands of pieces long. You'd have hundreds of each of A C T G, and once they're broken up the body does not "remember" what order they started out in, it just uses the puzzle pieces where it needs them.

I am going into so much detail on this because the point I want to make is this:

**********There is nothing in genetically modified DNA that is NOT in "regular" DNA.**********
ALL DNA is made of sugars, phosphates, A C G and Ts. THAT'S IT. They're made of the same ingredients, and your body breaks it down and uses the ingredients.

I'm not saying we shouldn't label GMOs or all GMOs are good; I'm just saying just because something has genetically modified genes in it does not mean it's going to hurt you.

Not only is it physiologically impossible, but they have done medical studies to make sure. They actually have done studies where they feed genetically modified corn to farm animals (I think chickens mostly) and test the food, food removed from the digestive tract at different points in digestion, and samples of the animal's body tissue and blood to see if any of the modified DNA survives and gets incorporated into their bodies. The most important points are:

1) "Feed-derived DNA is progressively degraded along the digestive tract." So, like I said, it gets digested! Both GMO and regular genes.

2) In a second study they actually continued to test the bird poop for genetically modified DNA. As of 4 days after the last feeding of GM feed, there was no trace of the DNA in their poop. So same thing, gets digested, doesn't stay in your body.

There was no difference in growth, development, or health between birds fed GM feed and birds fed regular feed in any of the studies I read.

Personally, I feel the main issues with GMO crops are environmental and socioeconomic issues. Planting and growing the crops can harm the environment, and also harms farmers.

It doesn't physically hurt you to eat them, like I said above. It all gets broken down into sugars, phosphates, and nucleotides. People get all freaked out about the "fish genes in tomatoes" thing... I mean, why? So what? What if you ate fish with tomato sauce on it? There would be fish genes and tomato genes in your stomach at the same time. They would just all get broken down. It makes ZERO difference if an adenosine molecule came from a fish gene that was in a piece of tuna or a fish gene in a GMO tomato. It physically CANNOT HARM YOUR BODY.

What COULD possibly harm you? One good example would be "roundup ready" crops. They aren't killed by weed killer, which means farmers can spray WAY MORE WEED KILLER than usual on the fields. It's not the GM crop that hurts you, it's the extra pesticide!!!

So, wash your produce well and avoid the "dirty dozen."

(the dirty dozen are the types of produce that have been tested and found to have the highest pesticide residues. It is recommended that if you can only afford some organic foods, you buy these fruits and veggies organic and save your money by buying conventional foods for other food items.

But really, all the extra weed killer is probably doing WAY more harm to the environment than it is to you, assuming you wash your produce.

Another GMO you may have heard of is Bt corn, the corn that makes its own pestidicide. Bt corn cannot hurt you. That's one of the better GMO crops, I think. Bt stands for a kind of bacteria that acts as a natural pesticide. When caterpillars try to eat it, they die. Sounds dangerous! It isn't. The bacteria have been collected from the soil and sprayed on crops for hundreds of years; the only difference is now the corn makes its own alkaloid (the compound that does the killing) instead of needing the bacteria to make it. It only harms the caterpillars of approximately THREE species of moths.

They have alkaline digestive systems; the toxin opens pores in the digestive tract, which makes them more susceptible to infection by bacteria in the environment, like E. coli. Are you an insect? Nope. Do you have an alkaline digestive tract? Nope! Ours is acidic. Bt alkaloids can't hurt you. They have also done multiple studies to show that it doesn't hurt other insects, like bees and butterflies, either. It literally only works on a couple of species, but since one of those is the "corn borer" it's a pretty handy little molecule!

However, it harms farmers to have to pay for patented seeds every year. Saving seeds saves money, as well as brings hardier crops. In the old days, farmers would save the seeds from their best plants, and over time a farmer in Iowa was growing plants best suited to his climate and soil, while a farmer in Oklahoma had slowly bred a very different plant best suited to Oklahoma. Now everyone buying Monsanto corn seeds is grown the SAME corn, across thousands of miles, which is ridiculous.

I also hate the idea of farmers being sued when GMO genes accidentally end up in their crops... Corn is a WIND POLLINATED plant, possibly the STUPIDEST place for "proprietary" genes you could possibly think of. It's impossible to keep them from spreading, and ridiculous that farmers can be sued for "stealing" genes the wind brings into their corn whether they want them or not.

Bananas, on the other hand, are a perfect crop for GMO. If you've ever eaten a banana you know they have no seeds. They can't spread any genes engineered into them to other varieties because even if you cross pollinate plants, they don't form any seeds! No hybrids!

Bananas are propagated by cuttings; a portion of a plant is cut and planted to make a new plant. All bananas are genetically identical! This is neat-o, but not good for the health of bananas. Why? There is no such thing as a banana plant that is more resistant to disease than others (because they're all identical!).

The bananas we eat are not the bananas our grandparents ate; that was a variety called the Gros Michel, and it is more or less extinct, driven out by fungal plant diseases that couldn't be stopped with pesticides (fungicides) anymore. Our bananas are a variety called the Cavendish, and they are threatened by similar diseases. TONS of stuff has to be sprayed on bananas to protect them from the multiple diseases they're susceptible to. We aren't at QUITE as high a risk of eating chemicals, because bananas have a thick peel we remove before eating. It IS dangerous for the farm workers to be around all those chemicals though.

What about organic bananas? They have to be grown on land that has never been infected with the most common banana diseases. So what happens when banana plants on an organic farm start showing signs of disease? Well, they can start using fungicides and become a conventional banana farm. But usually they don't. Burn it to the ground. Move on a few hundred kilometers, cut down some rainforest, and start over.

Neither solution (tons of chemicals; clear cutting rainforest) is great for the environment. A GMO banana that tastes as good and travels as well as the Cavendish, but has higher disease resistance engineered in, would be a wonderful development. I will go ahead and go on the record. I am fully in favor of GMO bananas.

I'm all for labeling. I want to be clear about that, at least. I am 100% for labeling what's in our food and where it comes from. I think we need MORE transparency in our food system, not less.

I think there should be labeling, and people should be able to make their own choices, but I wish I saw far LESS of this idea that eating food from a GMO plant is going to somehow make you ill or harm your body.

I keep harping on this but I can't help it... Genetically modified DNA doesn't have anything in it that "regular" DNA doesn't have! The only difference between the DNA that makes you, you, and and a tomato plant's DNA is what ORDER the ACGT molecules are in down the strand, and how long the strand is. It doesn't matter what gene or strand of DNA or whatever you eat; your body digests it and uses the component molecules it needs. It really, truly, honestly, does NOT know the difference.

So if you don't want to eat GMOs, don't eat them. That's fine. In fact it's a vote with your dollars, for a healthier environment and better options for farmers. Push for labeling and more transparency in our food system.

But please don't be afraid of them, or try to convince other people to be afraid of them, because they're "frankenfood" that's going to make you sick. Try to remember it's all made out of the same puzzle pieces.
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Member Comments About This Blog Post
    My problem is with the strands of DNA that we don't know what it's for - well, actually with the fact that there is a whole lot we just don't know. It seems a little...premature? to tout the positives of something we don't entirely understand (not that I think you are doing so - but I've read that side of this debate before).

    I also see a pretty big difference in hybridizing, which can be done in a backyard, and genetically modifying, which must be done in a lab. While I understand that they are not adding anything to DNA, and that it is all based on sound science, I think companies are more interested in financial gain than in feeding the masses. And financial gain for corporations is not always or even usually good for our collective health.

    Then, there is a huge issue with older varieties of plants disappearing completely. There are lots of varieties of corn that are gone forever, and bananas too. Seed companies have genetically modified plants to not produce seeds in some cases, particularly flowers - that way customers have to purchase a packet of seeds every year they want to grow those flowers.

    Your presentation of the whole issue is interesting. Thanks for taking the time to write it all down and for sharing it with us.
    2951 days ago
    This blog was a wonderful explanation and a voice of reason in the craziness! Like you, I haven't got a problem with genetic modification if it allows us to use less chemicals on our food. But I also agree that the lawsuits over Bt corn and soybeans are ludicrous.

    It think the part that scares me is having any large corporation, whose focus is only on profit, controlling so much of our food supply. Both farmers and consumers are the losers in that senario.
    2951 days ago
  • no profile photo CD12383123
    What a great explanation for an otherwise scary subject! I knew all this stuff in the back of my mind, but lacked the ability to put it into coherent phrasing.

    My biggest worry is the pesticides and all the garbage that they add to foods.

    Oh, and +1 for the bird poop experiment!
    "Bird poo...making science a little less scary!"
    3044 days ago
    Thanks for the explanation!
    3045 days ago
  • LEB0401
    oh. my. gosh.

    I had no idea... seriously, NO IDEA.

    This was incredibly eye opening. I will never buy another organic banana. I can't believe I fell into the smear campaigns without doing any actual research. Thank you a million times.
    3045 days ago
    Thanks for the info.
    3046 days ago
    Lots of debate over this issue when you google - just like so many other issues lots of disagreement over the "facts." I, too, am not alright with the lab involvement in these foods. So many things have come out as "improvements" only to be shown to be harmful after years of research and studies. The extra pesticides effect on our environment, not to mention our children, is a huge concern. At least labeling gives us a chance to choose.
    3046 days ago
    Thanks again for posting all this. I’m going to print it out for reference, especially the worst pesticide retaining foods. Maybe it’s because I’m so old that the DNA helix was a new discovery when I was in HS Biology, but messing with the molecules in a lab just doesn’t feel right. It’s good to know though that I won’t grow fish scales (LOL).

    The negative effect on farmers is something I didn’t know, but of course, that’s why companies get patents. The lawsuits over wind-borne pollination are scary too.

    Labeling would be the answer and the companies aren’t doing themselves any favors by dumping so much money into campaigns to oppose it. To the average person it makes them look guilty of something. IMHO the money would be better spent on education about GMO.
    3046 days ago
    WOW! Thanks for an explanation that was understandable. I personally don't have any objections to the GMO's. I have to admit to not really being all that interested in the science. If I really want healthy, no pesticide produce, I plant my own garden and/or buy from the local farmers market. I'm hoping the knees are up to gardening this year!
    3047 days ago
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