6 Hidden Ingredients in Foods You Probably Eat All the Time

We’re constantly eating (because, duh), but there are actually some ingredients in common foods that nobody really knows about. Oftentimes, these ingredients aren’t even directly listed in the nutrition information, but disguised within words that don’t sound as alarming. This is one of the main reasons that people have allergic reactions, only to find out what’s really in their food when it’s too late. To prevent this and any uncertainty about what you’re eating, Her Campus has compiled a list of some of the most common hidden ingredients, along with their alternate names if you want to avoid them!

1. Rennet

Also called: Microbial enzyme (only for vegetable rennet)


Also known as the enzyme that comes from the stomachs of cows, lambs and other animals, rennet is an ingredient found in a majority of cheeses. While the amount used varies depending on the brand and type, it’s practically necessary for the process of making cheese, meaning it’s hard to avoid! This can be alarming to vegetarians, so try to stick to the cheeses that don’t have rennet. According to nutritionist, chef and author, Patty James, there is another way to obtain non-animal rennet (for those with vegan diets), but it still alarms some. “There is a source of genetically modified rennet derived from plants injected with cow genes,” James says.

2. Yellow Dye No. 5

Also called: Tartrazine, E102


Yellow Dye No. 5 is found not only in a lot of foods, but also in shampoo, cosmetics products and drinks. “A lot of processed cereals contain dyes, such as Yellow #5, which may contain traces of lead and arsenic,” says Jennifer Calo, clinical registered dietician and nutritionist at Compass Nutrition. Studies have shown that elements like arsenic and lead have caused a multitude of health problems in people around the world. Processed foods in general tend to contain dyes. James says that Yellow Dye No. 5 can also contain mercury, which is known for being toxic, and benzidine, which has been linked to bladder and pancreatic cancers.

3. Trans fats

Also called: Partially hydrated, mono- and di-glycerides


While this doesn’t sound as shocking, nearly one in 10 processed products sold in the U.S. contains trans fat, according to a study from the Centers for Disease Control and Prevention. According to registered dietitian Adrienne Raimo, these can be found in anything from butter to chips. While avoiding trans fats altogether is ideal, it’s extremely difficult. Instead, the American Heart Association recommends that no more than 1 percent of your daily calories come from trans fats.

4. Sodium Nitrate

Also called: Nitrate of soda, Nitratine


Commonly found in hot dogs, bacon, jerky and other meats, sodium nitrate’s main purpose is to block the growth of bacteria. Though it may seem like something that would protect our health, a study done by the Cancer Research Center of Hawaii and the University of Southern California suggests that this preservative raises the risk for cancer. Studies have also shown that down the line, increased levels of nitrate can also lead to a higher possibility of death from diseases like Alzheimer’s and Parkinson’s. The World Health Organization recommends “an Acceptable Daily Intake for humans of 5 mg sodium nitrate or 3.7 mg nitrate per kg body weight, which equals 222 mg for a 60-kg adult.”

5. Shellac

Also called: Resinous glaze, Confectioner’s glaze, Pure Food Glaze, Beetle Juice


You might know about shellac due to the gel manicure craze, but it’s also found in your food. Jellybeans and candy corn are coated with this ingredient to appear shiny. Harmless, right? Well, that depends on if you’re into eating secretions of the Kerria Iacca insect because that’s what the substance is derived from. Watch out: You might even find this product in organic foods, such as on apples, to mimic their natural wax!

6. Rodent Hair


The FDA actually allows a certain amount of rodent hair for a variety of products. Their reasoning behind this is due to it being an “unavoidable defect.” As a result, these hairs are commonly found in cinnamon, chocolate and peanut butter.


If you were shocked by some of these ingredients, you probably haven’t been checking the nutrition labels on the food you eat. Even if you do, you might assume everything listed is safe, when that’s not always the case. While there are often alternative names, food companies are entirely aware of how often things go unnoticed, and will simply list the ingredients since the law requires them to. If you want to avoid things like shellac and rennet, it’s important to know what’s actually in your food!