【Medical Companion Travel】Will eating overnight dishes left over from the New Year cause cancer? Hurry up and forward it to the elders

On the first day of construction, talk about the big fish and meat that have not been eaten during the Spring Festival holiday...

It is often said that eating overnight dishes will cause cancer, so will the midnight meals that cannot be eaten repeatedly during the Spring Festival cause cancer? From a scientific point of view, what are the health risks of eating overnight dishes? Let's take a look!

The main basis for the carcinogenicity of overnight vegetables is that the nitrite it contains that is not carcinogenic itself will react with the decomposition products of proteins in the stomach with amines, and it has a strong teratogenicity and carcinogenicity of a class of carcinogen nitrosamines.

During high-temperature cooking, food will lose its own nitrate reductase activity. Long-term placement of heated food at room temperature is more conducive to the growth of bacteria, resulting in increased nitrite content and health risks.

The Ningbo Municipal Quality Inspection Institute has purchased 32 of the most common raw materials such as vegetables, meat and eggs in the local market, and cooked more than 30 kinds of home-cooked dishes for observation tests placed at room temperature (25 °C) and refrigerated (4 °C).

leaf vegetables

The experiment found that after 12 hours of room temperature, the nitrite content of leafy vegetables increased significantly, and even some exceeded the upper limit of nitrite (based on sodium nitrite) in pickled vegetables relevant regulations of 20mg/kg, and after 24 hours, some dishes reached more than 100mg/kg. After 24 hours of refrigeration, the nitrite content of all dishes is still within the safe value.

However, repeated heating of vegetables will make most vitamins inactive, and the nutritional value will be greatly reduced. Therefore, it is still recommended to eat fresh food as much as possible, develop a good habit of eating how much to do, and do not refrigerate for more than 24 hours.

Fish, meat, soy products, etc

Fish, meat, soy products themselves have a very low nitrite content, generally home cooked meat dishes overnight after the risk of nitrite increase is small, but the fish, meat and soy products placed at room temperature is very suitable for the growth of bacteria including harmful bacteria, after eating it is easy to cause gastroenteritis, food poisoning and so on.

Rice, pasta and other starchy foods

In a room temperature environment, long-term storage of starchy foods is easily contaminated with Bacillus cereus, which can cause abdominal pain, diarrhea, vomiting and other symptoms after consumption.

And without cooking high temperature sterilization of cold dishes, the bacterial content is higher, long-term placement is more likely to lead to health risks, it is recommended to eat when eating, do not overnight.

It is worth noting that overnight dishes refer to dishes that have been placed for more than 8-10 hours, not just dishes that have been placed overnight. Therefore, if there are leftovers to be left overnight, remember to put them in the refrigerator. In addition, the elderly and children generally have weak resistance and it is not recommended to eat leftovers often.

summary

Although eating overnight dishes often has certain health risks, the claim that eating overnight dishes causes cancer is also one-sided.

After cooking vegetables are refrigerated overnight, the nitrite content is much lower than the national standard for processed foods, so properly preserved overnight dishes are edible.

The health risks caused by long-term placement of meat dishes mostly come from harmful microorganisms, and the risk of carcinogenicity is also very low.