Sodium Nitrite
Nitrites and nitrates are used to inhibit botulism-causing bacteria and to maintain processed meats' pink hues, which is why the FDA allows their use. Unfortunately, once ingested, nitrite can fuse with amino acids—of which meat is a prime source—to form nitrosamines, powerful carcinogenic compounds. Ascorbic and erythorbic acids—essentially vitamin C—have been shown to decrease the risk, and most manufacturers now add one or both to their products, which has helped. Still, the best way to reduce risk is to limit your intake.
You'll Find It In: Oscar Mayer hot dogs, Hormel baconCaramel Coloring
This additive wouldn't be dangerous if you made it the old-fashioned way—with water and sugar, on top of a stove. But the food industry follows a different recipe: They treat sugar with ammonia, which can produce some nasty carcinogens. How carcinogenic are these compounds? A Center for Science in the Public Interest report asserted that the high levels of caramel color found in soda account for roughly 15,000 cancers in the U.S. annually. Another good reason to scrap soft drinks? They're among The 20 Worst Drinks in America.
You'll Find It In: Coke/Diet Coke, Pepsi/Diet Pepsi
More: What You Should Know About Soft Drinks
Castoreum
Castoreum is one of the many nebulous "natural ingredients" used to flavor food. Though it isn't harmful, it is unsettling. Castoreum is a substance made from beavers' castor sacs, or anal scent glands. These glands produce potent secretions that help the animals mark their territory in the wild. In the food industry, however, 1,000 pounds of the unsavory ingredient are used annually to imbue foods—usually vanilla or raspberry flavored—with a distinctive, musky flavor.
You'll Find It In: Potentially any food containing "natural ingredients"
More: 10 Grocery Tips for Healthy Shoppers
Food Dyes
Plenty of fruit-flavored candies and sugary cereals don't contain a single gram of produce, but instead rely on artificial dyes and flavorings to suggest a relationship with nature. Not only do these dyes allow manufacturers to mask the drab colors of heavily processed foods, but certain hues have been linked to more serious ailments. A Journal of Pediatrics study linked Yellow 5 to hyperactivity in children, Canadian researchers found Yellow 6 and Red 40 to be contaminated with known carcinogens, and Red 3 is known to cause tumors.
The bottom line? Avoid artificial dyes as much as possible.
You'll Find It In: Lucky Charms, Skittles, Jell-OThe Domino Effect: Sugar doesn't just come in the form of cookies and candy. Discover the insidious ways it can creep into your diet with 9 Sneaky Sources of Sugar.
Hydrolyzed Vegetable Protein
Hydrolyzed vegetable protein, used as a flavor enhancer, is plant protein that has been chemically broken down into amino acids. One of these acids, glutamic acid, can release free glutamate. When this glutamate joins with free sodium in your body, they form monosodium glutamate (MSG), an additive known to cause adverse reactions—headaches, nausea and weakness, among others—in sensitive individuals. When MSG is added to products directly, the FDA requires manufacturers to disclose its inclusion on the ingredient statement. But when it occurs as a byproduct of hydrolyzed protein, the FDA allows it to go unrecognized.
You'll Find It In: Knorr Noodle Sides, FunyunsMore: 9 Natural Foods to Beware
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