Genetically modified food raises lots of questions, from whether it’s safe to the environmental benefits. Science writer Stevie Shephard delves behind the headlines with a beginner’s guide.
You’ve probably heard about genetically modified organisms (GMOs) – also known as genetically engineered foods or just ‘GM’ – and you might be wondering what all the fuss is about. Here, we explain the basics.
What are GMOs?
‘GMO’ refers to any living thing that’s had its DNA altered using genetic engineering. This could be a plant, animal (including humans) or bacterium and it’s usually done to introduce a desirable trait into the organism, such as larger fruit or drought resistance.
You'll often see discussion of GM foods accompanied by images of fruit and veg with scary-looking syringes stuck in them (presumably by evil scientists), but these bear little resemblance to reality.
Humans have actually been performing a low-tech version of the GM process for thousands of years through selective breeding. Ancient farmers did it with maize (that’s sweetcorn to us), and transformed a tough, indigestible grain into the juicy yellow kernels we know today.
Genetic engineering allows us to directly alter the DNA of organisms without having to go through the process of breeding them over many generations. The gene for a desirable trait is isolated from a separate organism and inserted into the target, either manually or by attaching it to a (harmless) virus. GMOs can be used to treat disease, protect the environment and, of course, produce food.
Are GM foods bad?
Well, it’s complicated. Despite what many people might claim, there is no evidence that GMOs are bad for you to eat, use, touch, rub into your skin or feed to your children.
In short, there is little difference between altering DNA through selective breeding and altering it through genetic engineering, and your body can’t tell the difference between GM and non-GM foods.
Genetic engineering can actually be used to increase the nutrient density in food. The now famous “Golden Rice Project” is a good example. Food scientists modified ordinary rice to be rich in vitamin A and this is now grown in areas where vitamin A deficiency is a major cause of child mortality and blindness.
Crops can also be modified to produce higher yields and grow in drought-stricken areas. As well as being generally good for business, these modifications could also go a long way to alleviating famine and hunger around the world.
But that’s not the whole story – and one of the reasons is pesticide. Some GM crops are altered to be resistant to certain pesticides, which could increase pesticide use on them. Alternatively, some are made to produce their own bug-repelling properties, actually reducing the need for additional pesticides.
Both approaches end up killing “pests” – some of which are actually vital pollinators – however this also happens with conventional, non-GMO crops and is one of the realities of intensive farming.
On balance, it could be argued the global benefits of GM crops currently outweigh the risks, at least according to a peer-reviewed 2014 analysis into the impact of GM crops, published in the science journal PLOS One.
So what’s the problem?
While the health issues may have been over-emphasised by the media, there are still plenty of reasons why GMOs are controversial.
One major problem is the fact that a crop can become the intellectual property of a private company. Traditionally, farmers save some of the seeds from their current crop to plant for next year’s harvest.
But when a company owns the rights to a GM crop, they can (and do) forbid farmers from doing this, forcing them to purchase new seed from the patent owners every year. Even if a farmer doesn’t grow GM crops, they can blow in from neighbouring fields, making it necessary to purchase a licence for them – or face heavy fines. GM critics say that this gives large corporations too much control over agriculture and the power to exploit farmers.
There also remain a handful of scientists who still have concerns about ‘unknown’ long-term implications. Anti-GM cellular biologist Dr David Williams says that a genome is not a static environment and claims “inserted genes can be transformed by several different means [which] can happen generations later”. Talking to the journal Scientific American, he argues that potentially toxic plants could therefore slip through testing in future.
Even if most experts support GM technology, some critics argue that scientists could be afraid to challenge the majority and publish anti-GM studies, because they would face attacks on their reputations and receive less funding for their research.
Whether or not that’s true, it doesn’t change the fact that almost all anti-GM studies to date have been discredited or retracted – debunked by the scientific community for using misleading, unscientific methods.
What’s in a name?
The term 'GMO' doesn’t mean a lot in itself. It’s basically a blanket term for any organism that has had its genes altered. As such, the upsides and downsides of GMOs are not as simple as healthy or unhealthy, good or bad.
There’s much more to say about the potential of GM technology. But as a consumer, it’s worth noting that currently approved GM foods are likely to be indistinguishable from non-GM produce; they may even be cheaper, tastier or more nutritious. The politics of GMOs, however, are still in their infancy.
Ultimately, it’s down to personal, informed choice. Get the facts and be wary of anyone trying to scare you about what’s in your food – they may just be trying to sell you an alternative. A good way to avoid being swayed by the pro- or anti-GMO lobbies is to get the facts from independent projects such as the Genetic Literacy Project.