Frankenfoods sound like something that only Frankenstein would eat, right? Actually, it’s not just Mary Shelley’s lab-made monster who eats them – you do, too. Every day. What are they? They’re GMO foods – foods containing genetically modified organisms.

Commonly known as GMOs or GM organisms, genetically modified organisms are laboratory-created plants or animals that have had genes from viruses or bacteria spliced into their DNA in order to engineer certain traits. Usually GM crops are engineered to be more drought resistant, higher yielding, and herbicide and pesticide resistant. By creating pesticide and herbicide resistant plants, bio engineers hope to increase crop yields. Unfortunately, that resistance means that GM crops can be doused with huge amounts of chemicals that can make their way into your food supply.

The corporate ethics of GM foods are shady, to say the least. Unlike regular plants, genetically modified organisms can be patented. The prospect of global corporations having a patent on the world’s food supply is sobering. GM patents cover not only the parent organism, but also all successive generations. This hurts small farmers who can’t collect seeds from one year’s harvest to use the following year. Instead, corporations can force farmers to buy new seeds each and every harvest season.

So, other than the fact that they sound a little creepy and are associated with questionable ethical practices, what’s wrong with eating GMO foods? That’s the problem – nobody knows for sure. Some people experience severe allergic reactions to genetically modified foods that they do not experience from eating non-modified versions of the same product. The long-term effects on humans are as of yet undocumented. They could cause cancer or a host of other health problems, and this uncertainty has caused the European Union and other countries like Japan and Australia to ban genetically modified foods.

GM foods have already shown negative environmental side effects. A type of genetically modified corn, called Bt corn, has reduced the already dwindling population of Monarch butterflies that rely on corn as their main dietary staple. Bt corn is engineered to repel Lepidoterans – butterflies and moths. Unfortunately, it is also toxic to them and is decimating already endangered butterfly populations.

Creepily, in the United States companies are not required to label foods that contain GMO ingredients. The only way to avoid them is to be informed as to what foods tend to be genetically modified. Organic foods don’t have genetically modified ingredients, but other than that it’s a hit or miss. Many papayas, zucchinis, and sugar beets are GM. Around 85% of soybeans grown in the United States are genetically modified. Also, a lot of corn – even what you see sold at farmer’s markets and roadside stands – is genetically engineered. Because corn is often GM, its derivative products such as the ubiquitous high fructose corn syrup are also GM. Sugar is more natural, right? Not necessarily. Since 2012, the FDA has allowed genetically modified beet sugars to be labelled simply as sugar, which means that anything containing sugar might be genetically modified. Looking for another reason not to indulge in that pint of Breyer’s? Many cows are given recombinant bovine growth hormones and fed genetically modified hay, so even dairy products aren’t necessarily GM-free. Clearly, avoiding GMO foods can be a tricky task – some experts estimate that up to 70% of foods on stores shelves contain genetically modified products! Unfortunately, once the genie – or gene, rather – is out of the bottle, there’s no putting it back.