Subtitles section Play video Print subtitles This episode of Real Science is brought to you by CuriosityStream. Watch thousands of documentaries for free for 31 days at curiositystream.com/realscience The 1840s were a bleak time in Irish history. Imagine one in every six people you know slowly painfully dying of starvation or disease. Then in the next few years, as many people leave the country and never come back. And over the next few decades the number of people in your town is half of what it used to be. During the Irish Famine, 1 million people, or about 15% of the population died. Another 1.5 million people fled the country in its immediate aftermath leading to a permanent decline in the Irish population. Ireland and the whole world was changed forever due to one persistent devastating fungus. The late blight or phytopthora infestans is a fungus that attacks the potato plant leaving the potatoes inedible. The fungus spores spread easily in the wind and quickly infect neighboring plants. It was particularly disastrous to Ireland due to the potato being hugely relied on for food by the rural poor. By the 1850s the widespread blight eventually ran its course but it did not disappear entirely. To this day blight remains a significant problem for potato and tomato growers that has to be battled year after year. 160 years after the famine, late blight is still a five billion dollar problem for the global potato industry. Some potatoes can be bred to have some resistance to the fungus but this can take decades. So the reality is that farmers need to spray their crops with lots of fungicide every week indefinitely. But in 2015 a breakthrough occurred - a new variety of GMO potato was developed that can resist the very blight that killed so many. Using blight resistant genes from wild potato plants, scientists precisely adapted a version of the common potato to withstand the fungal disease. This GM potato, called the Innate Potato, can save farmers huge amounts of time and money and can reduce the amount of environmentally damaging pesticide that gets sprayed on the fields - up to eighty or ninety percent. And so naturally Ireland with its history of massive crop failure killing a million people and its commitment to green agriculture says - nope let's ban it and in fact let's try to ban all GMOs. Okay so what is going on? "so it's made in a laboratory and more often than not they're inserting viruses or bacteria into these plants" "what you need to know is that the process itself is flawed." We've all probably seen debate like this. GMOs are bad, they're bad for you, they'll give you cancer, they'll give the world cancer, and that they are literally the devil. Yet others say GMOs will end world hunger, stop climate change, and that they're completely harmless. There are so many videos articles and interviews on both sides of this and the amount of unresearched unscientific claims out there to sift through is infinite. There's an ever-present sense of hysteria when discussing anything to do with GMOs and this public sentiment informs government decisions for better or for worse...usually for worse. But like most things, the issue of GMOs is not as black and white as many people would lead you to believe. GMOs are not what will save the world nor are they what will destroy it. Before we get into whether or not GMOs are good or bad, let's first understand what they even are. Genetically modified organisms are organisms that have been altered using genetic engineering methods. The key steps involved in genetic engineering are first to identify a trait of interest. Then isolate that trait, insert that trait into a desired organism, and then propagate or breed that organism. Most of the GMOs on the market today have been given genetic traits to improve their quality, provide tolerance to drought, or to provide protection from pests like the GM potato I mentioned before being resistant to fungal infection. Another big example of this in the world of GM foods is insect resistance. BT maize for example is a strain of insect resistant corn. Corn farmers are challenged with a number of pests, but the most damaging are caterpillars that are stalk borers, ear or leaf eaters, and beetle grubs that eat the roots. The European corn borer for example was nicknamed with the billion dollar bug because it costs growers over a billion dollars annually in insecticides and lost crop yields. For years farmers have largely relied on chemical insecticides to protect their crops, but in 1996 farmers were introduced to genetically engineered corn with resistance to the European corn borer. These genetically modified plants produce proteins derived from the soil bacterium bacillus thuringiensis, hence the name BT maize. The proteins that are produced by the bacteria are crystal proteins which are toxic to caterpillars like the corn borer, and are introduced into the corn through a process called transgenesis. The first step in this process is identifying an organism with the desired trait - in this case something that is toxic to caterpillars. Around a hundred years ago silkworm farmers noticed that populations of silkworms were dying and scientists discovered that a naturally occurring soil bacteria was causing the deaths. Scientists now know that these soil bacteria that are toxic to silkworms are also toxic to the European corn borer. The next step in the transgenesis process is to extract the desired DNA out of the bacteria. This is accomplished by taking a sample of bacteria containing the gene of interest and taking it through a series of steps that separate the DNA from the other parts of the cell and isolate the gene of interest, usually using cloning vectors. The next step is gene insertion, in our case getting the BT gene into the corn. Since plants have millions of cells it would be impossible to insert a copy of the transgene into every cell. Therefore tissue culture is used to propagate masses of undifferentiated plant cells called callus, which are kind of like stem cells in humans. These are the cells where the transgene will be added. The transgene is inserted into some of the cells using various techniques, such as with a gene gun or by electroporation. The main goal of these methods is to deliver the transgene into the nucleus of a cell without killing the cell. The cells can then be treated with a series of plant hormones allowing it to grow into an entire plant. You now have corn crops that contain their very own insect resistance. The huge benefit of this is that one, the corn crops don't get destroyed by these caterpillars and two, that less insecticide is needed to combat them. Studies have shown a pretty indisputable decrease in insecticide use when BT or similar crops are planted. GMO crops can also stave off malnutrition in many parts of the world. Vitamin A deficiency has been recognized as a significant public health problem continuously for more than 30 years. The problem is particularly severe in populations where rice is the staple food and diversity of diet is limited, as white rice contains no micronutrients. Vitamin A deficiency is the leading cause of preventable blindness in children and increases the risk of disease and death. Mirroring our Irish Famine example from before, these deaths are caused by diseases which thrive in malnourished people. To combat this, scientists engineered what is called Golden Rice. This rice produces beta-carotene which is the precursor of vitamin A. It's the same pigment found in carrots and just one cup of golden rice per day per person can prevent vitamin A deficiency and has the potential to save thousands of lives. It's never possible to prove a food is completely a hundred percent safe .We can only say that no hazard has ever been found to exist. And there have now been over 500 scientific studies looking for and failing to find conclusive risk to human health from GM crops. Take the example of crops containing insect resistance - many studies have confirmed that BT toxins can only work in alkaline environments and require specific enzymes and receptors in the insect gut to cause toxicity. Humans have very acidic stomachs and lack these enzymes and receptors and so are not affected by the BT crystal protein. Other ways scientists test GM foods before releasing them to the public are by simulating the behavior of GM proteins in the human gut to see whether the proteins degrade during digestion, or more conclusively, to test the GM crop on animal models like lab rats. The rats are first fed a single meal of the GM crop or protein to test for acute toxicity. Then the rats are fed repeated meals of GM food for 90 days and sometimes up to a year to test for chronic toxicity, which is the type of harm that only appears with repeated use. Despite many studies like this failing to find anything harmful about GMOs there is still radical opposition. In 2013 anti-gmo activists, heavy air quotes there, invaded and destroyed a field trial for Golden Rice in the Philippines setting the study back months and jeopardizing the technology's implementation. Ireland as we mentioned before is trying to approve blanket restrictions on GMOs citing the need to maintain their international reputation as a green sustainable food producer. So all this leaves many of us thinking why are people so opposed to something that seems to be so good for the world? Is there any basis for this? While the misinformation that spread seems endless and the number of bogus claims that circulate are frustrating it would be disingenuous to pretend that the rise of GMOs has only been a good thing, but not because of the reasons most anti GMO groups on Facebook and Irish politicians are claiming. While things like BT crops do reduce insecticide use there is another side to the coin. One of the most common types of GMO crop around the world are ones that are resistant to herbicide, specifically glyphosate. Roundup Ready is the Monsanto trademark for its patented line of genetically modified crop seeds that are resistant to its glyphosate based herbicide Roundup. So in an opposite way to the BT crops we discussed before Roundup Ready crops mean farmers can use more herbicide on their crops. One study shows that on average adopters of GE glyphosate tolerant soybeans used 28% more herbicide than non-adopters. Another study says that globally glyphosate use has risen almost 15 fold since Roundup Ready crops were introduced in 1996. And roundup is not exactly good for people or the environment. Glyphosate can leak into soil and surrounding water affecting wild plants and animals, which ultimately can hurt the food chain. And recently the World Health Organization has declared roundup to be probably carcinogenic, after years of debate around this point. Other research points to its possible effect on mitochondrial and brain function and animal models. This research is still being carried out and there's increasing concern about the chemical combinations used in commercial weed killers and their long-term impacts especially for the people using it every day. And right now Monsanto is embroiled in lawsuits with people alleging that Roundup caused their cancer. A jury in California just awarded a couple two billion dollars in a verdict against Monsanto which is the third in a string of recent court decisions involving claims that the company's Roundup weedkiller caused their cancer. And while a jury is not a scientific panel of experts and there's much debate around the truth of these cancer claims, the money was awarded on the basis that Monsanto manipulated its own research, colluded with regulators, and intimidated scientists to keep secret the cancer risks of glyphosate. We could make a whole video just about the shady business practices of Monsanto, so it is not implausible to think that Monsanto is capable of something like this. So as we can see this is a nuanced conversation and any doubt people may have about this hugely complicated subject can easily be exploited. Pew Polls have found that some 49% of US adults surveyed said that foods with GM