Rumor: Long-term eating leftovers can cause cancer because leftovers contain nitrite.
Truth: Under normal circumstances, the nitrite content in leftovers does not reach a level harmful to health. It is not a big problem to eat leftovers occasionally.
Nitrite in leftovers is not produced out of thin air, it is produced by nitrate reduction through enzymes of vegetables themselves or enzymes produced by bacteria.
Cooked leftovers are very suitable for bacterial growth, so nitrite will be produced.
Some studies have shown that if a newly prepared dish is put in the refrigerator without turning it over, the nitrite content will only increase from 3 mg/kg to 7 mg/kg the next day, which is far lower than the national standard.
However, the production of nitrite is mainly due to the activity of bacteria in leftovers, and there are still certain health risks. Therefore, it is recommended that everyone eat as little or no leftovers as possible.