Why have nitrates and nitrites in cured meats been controversial?

The use of nitrite and sodium nitrate in cured meats is a standard practice for preservation, as these food additives effectively inhibit the growth of bacteria that cause food poisoning and help maintain the meat's desirable red color.12

However, this practice is controversial due to significant health concerns. When ingested, nitrite can react with stomach acid to form nitrous acid, which may then react with certain organic compounds to produce nitrosamines. Because some nitrosamines have been shown to cause cancer in laboratory animals, the United States Food and Drug Administration strictly regulates the amount of nitrite permitted in food products. To mitigate these risks, manufacturers often include other additives, such as sodium erythorbate or ascorbate, which can help reduce the formation of harmful compounds while still supporting color development.12