Genetically modified foods (or organisms, a.k.a. GMOs) are one of the most controversial topics of our generation. Although the conversation about whether we should be consuming these products has died down, most people are still unaware of what GMOs are and how frequently we encounter them.

Basically, GMOs are plants and animals that have been genetically altered through their DNA to make them resistant to diseases or pesticides, which are sprayed on crops to kill bugs. This means there are potentially tons of chemicals and hormones in your food that could harm your body. There’s been a huge pushback to stop farmers from growing genetically modified foods and using pesticides, but produce sold in local markets still pose threats to humans, animals, and the environment.

If this concerns you, take note of five genetically modified foods you may want to avoid:

1. Corn

Corn is almost always genetically modified in some way to be resistant to herbicides like Roundup, which kills weeds. According to the Center For Food Safety, about 85% of corn grown in the United States is genetically modified. Corn syrup, dairy, and even certain types of cosmetics all contain GMO corn product.

2. Soy

A 2013 study conducted by a team of Australian scientists and U.S. researchers found that pigs fed a diet of GMO grains showed higher stomach inflammation than pigs who dined on conventional feed. In 2014, the U.S. Department of Agriculture found that 93% of soy grown in the U.S. is engineered to be herbicide-resistant, but don’t worry fellow vegans—major soymilk and tofu brands are usually GMO-free.

3. Canola

You know that cheap oil you buy for your brownie mix because you think it’s the same thing as vegetable oil? Yeah, that’s canola oil and as of 2005, 87% of all canola crops in America were genetically modified. Canola is actually short for “Canadian oil low acid” and has been used historically as industrial oil—ew!

4. Milk

Dairy cows are often given rBGH, a growth hormone that has been banned in the European Union, Japan, Canada, New Zealand, and Australia, to increase milk production. A 2010 study done in Japan found that men’s testosterone levels, in both children and adults, decreased after drinking commercial milk.

5. Yellow Crookneck Squash & Zucchini

These winter favorites are bioengineered to be virus and herbicide-resistant. According to the Non-GMO Project and the Institute for Responsible Technology, approximately 25,000 acres of GMO squash and zucchini are grown in the United States, creating some of the most commonly genetically altered produce in the country.