Aaron Carroll: Since our first episode, you've begged us to cover genetically modified organisms, or GMOs.  Honestly, I can't tell if those of you who are asking us to do this expect us to tell you they're awesome or the worst thing to happen to humanity ever.  This is one of those topics people feel so passionately about that I'm guaranteed to make a lot of you angry no matter what I say.  But we never let that stop us.  GMOs are the topic of this week's Healthcare Triage.

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GMOs are food made from stuff that's had its DNA changed by genetic engineering.  For the last 12,000 years or so, farmers or scientists have changed plants or animals by breeding them carefully to get the traits they wanted.  Today, scientists have the ability to change DNA directly.  They've been doing so for decades.  How?  Well, first they find some organism that has an ability that they like--maybe there's a bacteria that's resistant to a certain poison.  It does so by manufacturing an enzyme that breaks down the poison before it can do any harm.  Scientists want to make crops that are resitant to this poison.  So they get in the DNA and harvest the gene, then they stick it into the genes of crops.  This really happens!  Science made certain crops more resistant to certain weed killers.  Then, farmers can spray fields indiscriminately and be sure that everything dies but the crops.  This practice could also theoretically make crops that are more nutritious or able to grow in different climates.  There's a lot of potential for good here.

It's important to recognize that this kind of thing does occur in nature.  DNA mutations are one example of the kind of stuff just occurring naturally.  The science of GMOs just speeds it up, albeit dramatically, and allows for more specific changes than nature usually allows.  GMOs are really, really common.  More than 90% of the soybeans planted in the United States are GMOs.  About 80% of corn and cotton, too.  Well over half of the processed foods that you buy every day have some GMO in them.  

Most of the GMO crops are grown in the United States.  Second place goes to Brazil.  Then Argentina, then India and Canada.  Last year, about 12% of all farmland in the world was growing GMOs.  The controversy comes from the fact that a lot of people believe that GMOs are dangerous.  They think that altering genes is a messy business that can have unintended consequences.  But it's important to remember that genes get altered all the time.  It's how random mutations occur that lead to evolution, plus, how else do you think we're gonna get the X-Men?  Don't take my word for it, to the research!

The Institute of Medicine and the National Research Council of the National Academies put out a report in 2004 reviewing all of the available data.  They concluded that there was no evidence at all that GMO food posed any greater danger to people than conventionally grown crops.  The European Union conducted its own research into the safety of GMOs.  Let me quote from their report: "The main conclusion to be drawn from the efforts of more than 130 research projects covering a period of more than 25 years of research and involving more than 500 independent reseach groups is that biotechnology and, in particular, GMOs, are not persay more risky than conventional plant breeding technologies."  The American Medical Association agrees.  So does the US National Academy of Sciences, the British Royal Society, and the World Health Organization.  That doesn't make many GMO objectors feel safe.  It likely doesn't make many of you feel safe either.

One concern comes from people who are worried that there could be new allergies to these foods, and although companies usually do test for allergies, they could do more.  I don't disagree.  But some argue that since it's impossible to test for all allergies, then we should be wary.  That's somewhat defeatist.  You can't test for all allergies for everything, even if it's not genetically modified.  That's a standard no one applies ever.  

Some other people think that GMO crops lead to increased use of herbicides, which could be toxic.  That's worth monitoring and studying, but it's certainly not proven.  But this brings up a larger question about whether GMOs are bad for the environment.  The evidence is conflicted here.  GMOs can, in many ways, lead to fewer chemicals being used, as farmers can use powerful stuff they know won't kill their crops.  Of course, this can lead to the development of resistant strains of pests.  That's happened recently when farmers didn't plant crops liike they were supposed to.  Moreover, it's possible that the genes that we stick into crops can get out of the lab.  This does happen, as it did in Oregon last year, when a strain of wheat that hadn't yet been approved was found growing in a field.  

Of course, and this is critcal, this kind of thing happens without GMOs, too.  Bacteria develop resistance to antibiotics without any genetic modification on our part.  Weeds get resistant to herbicides without out tinkering as well.  Life adapts and evolves.  This debate gets down to arguments about who has the evidence behind them.  But it gets complicated by the fact that much of the research is done by companies that have an inherent conflict of interest.  

The Genetic Engineering Risk Atlas has collected more than 1,080 studies, in general, about a third of them, no small amount, are independent.  They published a systematic review in 2013.  They looked at the most recent decade of studies to describe the scientific consensus as of now.  I'll quote them: "The scientific research conducted so far has not detected any significant hazards directly connected with the use of GE crops; however, the debate is still intense."  They also said, "An improvement in the efficacy of scientific communication could have a significant impact on the future of agricultural GE."

We agree.  We hope this video helps.  

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