Green leafy vegetables can't be eaten for a long time because they contain a lot of nitrate, especially cabbage and spinach. After repeated heating, it will be converted into carcinogens harmful to the body.

Some people like to put the food cooked the night before directly in the refrigerator and take it to work the next day. Try to choose vegetables such as roots and cauliflower.

Extended data:

Harmful substances in vegetables overnight

1, bacteria multiply. People habitually put overnight dishes in the refrigerator, which will breed a lot of bacteria if they stay wet for a long time. When they continue to heat the next day, they can't completely kill the bacteria, which will lead to gastrointestinal diseases and even food poisoning in the long run.

2. Produce nitrite. The nutritional value of green leafy vegetables was destroyed overnight, and nitrite was also produced. As long as nitrite enters the stomach, it will form a strong carcinogen and induce the occurrence of gastric cancer.

For the health of family members, try not to eat overnight dishes, especially overnight mushrooms and seafood, otherwise a large amount of ammonium nitrite will be produced in the body, causing serious harm to the body and even food poisoning. Eat more fresh vegetables and fruits, and don't leave the food for too long, otherwise it will reduce the nutritional value inside.

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