The first is the corn on the roadside stalls, because this kind of corn usually adds a lot of flavors and food additives. Although it smells sweet and delicious, its nutritional value is extremely low and even harmful to health.
The second is corn that has been left for too long. Many people left after eating, so don't eat next time. In addition, raw corn can't be eaten for too long, because this kind of corn will produce aflatoxin, which is harmful to the body.
Finally, half-baked corn, some people are too eager to eat when cooking corn, resulting in some corn not fully cooked. This kind of corn is inedible, which will do great harm to the body and even cause diarrhea.