What did you have for lunch today? If you ate a turkey sandwich and low-fat potato chips, you may have consumed a few unexpected ingredients, too. Perhaps some potassium bromate in your bread or sodium nitrite in your turkey. And those chips, were they made with olestra?

The foods currently lining U.S. supermarket shelves contain hundreds of additives designed to enhance color, texture, flavor, and shelf life. And the Food and Drug Administration (FDA) receives about 100 new additive approval requests each year. While these substances have been deemed safe by the FDA, some still question their short- and long-term health effects.

Ready to find out what you're really eating? Start by taking a closer look at the food label and steering clear of these potentially dangerous additives:

1. Potassium Bromate. This dough conditioner and bleaching agent, which was once widely used in bread baking, is considered a category 2B (possibly carcinogenic to humans) carcinogen by the International Agency for Research on Cancer (IARC). In 1993, the World Health Organization recommended its removal from all foods, and though it has been banned in many countries, it's still permitted in the United States and Japan. Potassium bromate is still used in Sunbeam and Wonder bread, TastyKake products, and buns from fast-food chains Burger King, Arby's, and Wendy's, according to the Center for Science in the Public Interest.

2. Sodium Nitrite. Nearly all processed meats are made with sodium nitrite: breakfast sausage, hot dogs, bacon, lunch meat, and even meats in canned soup products. Yet this ingredient may be a precursor to highly carcinogenic nitrosaminespotent cancer-causing chemicals that may accelerate the formation and growth of cancer cells throughout the body. In a University of Hawaii study, participants who consumed the most processed meats showed a 67 percent increased risk of pancreatic cancer over those who consumed little or no meat products. The U.S. Department of Agriculture (USDA) actually tried to ban sodium nitrite in the 1970s, but was preempted by the meat processing industry, which relies on the ingredient to make foods look more appealing. Some meats are now processed without using sodium nitrite, and the USDA has set limits on the quantities in which it can be used.

3. Butylated hydroxyanisole (BHA). This preservative, used to prevent fats from going bad, can be found in butter, meats, chewing gum, dehydrated potatoes, and beer. According to the International Agency for Research on Cancer, part of the World Health Organization, it may act as a precursor to cancer. In addition, the National Institutes of Health (NIH) describes BHA as reasonably anticipated to be a human carcinogen.

4. Olestra. A fat substitute used in crackers and potato chips, Olestra is marketed under the brand name Olean. This synthetic fat is not absorbed by the body and can contribute to abdominal cramps and diarrhea. Furthermore, Olestra may inhibit the body's ability to absorb beneficial fat-soluble nutrients, including lycopene, lutein, and beta-carotene. In two Proctor & Gamble studies, eight grams of Olestra a day (equivalent to a daily ingestion of 16 potato chips containing Olestra) caused dramatic depletion of important carotenoids and fat-soluble vitamins in just two weeks.

5. Monosodium glutamate (MSG). Used as a flavor enhancer in many packaged foods, including soups, salad dressings, sausages, hot dogs, canned tuna, and potato chips, MSG may pose serious health risks. The FDA has identified a condition dubbed MSG Symptom Complex, which can cause headaches, numbness, and drowsiness. People with severe, poorly controlled asthma may be among those prone to the condition and may suffer temporary worsening of asthmatic symptoms after consuming MSG.

Subtracting Additives
So, how do you remove, or at least minimize, these potentially dangerous ingredients from your diet? Start by sticking with fresh, whole foods whenever you can, and get in the habit of always reading the label so you know exactly what you're putting in your bodyand what you're leaving out.