This is reportedly the worst one. It's used to preserve color in foods and to flavor some of our favorite meat products--bacon, ham, hot dogs, luncheon meats, smoked fish, and corned beef. Turns out grilling these meats can make them even worse for you. It transforms into a reactive compound that is shown to cause cancer.

These preserve common foods that we eat every day--cereals, chewing gum, potato chips and vegetable oils. They keep fats and oils from going bad.

The oils that have been sitting in your cupboard for up to a year have propyl gallate in them. It's used to prevent fats and oils from spoiling.

This is a common one that most people already try to avoid. It's an amino acid that's generally found in Asian foods, soups, salad dressings, chips, and frozen entrees. MSG can cause headaches and nausea, which is why so many people avoid it.

Another common preservative that most people know about. Manufacturers are required to list the amount of trans fats in any given food.

Check your diet foods for these. You may think you're being healthy, but you could be doing yourself more harm than good. If you can't do without, try using real sugar in your coffee--in moderation, of course.

A new artificial sweetener used in soft drinks, baked goods, chewing gum, and gelatin desserts. It's not a big concern if used in moderation.

Blue 1, 2; Red 3; Green 3; Yellow 6: Blue 1 and 2 are a low risk, but Red 3, Green 3, and Yellow 6 are dangerous. Found in fruit cocktail, candy, beverages, and baked goods, they are known to cause thyroid tumors in rats and have been linked to bladder cancer.

A synthetic fat that stops fat from absorbing into the digestive system. The outcome leads to a very upset stomach. Olestra can be found in potato chips.

This is the rarest of preservatives, but still legal in the states. It's used to increase the volume in breads. The smallest amount of bread could put you at risk--the best thing to do is read labels. California requires that a cancer warning label be put on any product that has this ingredient.