1. Sodium nitrite
The most dangerous additive to red flag—until we know more— is the preservative sodium nitrite, used to preserve, color, and flavor meat products. Sodium nitrite is commonly added to bacon, ham, hot dogs, luncheon meats, smoked fish, and corned beef to stabilize the red color and add flavor. The preservative prevents growth of bacteria, but studies have linked eating it to various types of cancer. "This would be at the top of my list of additives to cut from my diet," says Christine Gerbstadt, M.D., M.P.H., R.D., L.D.N., a spokesperson for the American Dietetic Association. "Under certain high-temperature cooking conditions such as grilling, it transforms into a reactive compound that has been shown to promote cancer."