Scientists believe that avoiding food is likely an effective defense strategy, and this type of allergic reaction can limit our exposure to harmful stimuli to prevent further damage. Many people have more or less disliked foods, such as green peppers, shiitake mushrooms, eggplants, celery, milk... Especially when they were young, in order to avoid eating disliked foods, they had to engage in intellectual battles with their elders and even be harshly scolded. Picky eating has always been seen as a bad habit. Recently, scientists have published two consecutive papers in the journal Nature and found that being picky eaters may not be a bad thing. Avoiding food may be a protective mechanism for allergies, which in our impression are usually an acute bodily reaction: after the allergen enters the body, it is excreted through sneezing, coughing, vomiting, diarrhea, and other means. Sometimes it comes with fatal consequences, such as someone eating seafood or peanuts and directly entering the ICU. However, scientists have found that allergies actually have a very subtle manifestation - avoidance. That's right, I don't like it, maybe it's also an allergy. When the immune system comes into contact with allergenic foods, it sends signals to the brain, arousing aversion and encouraging people to avoid such foods. During this process, the immune cells responsible for communication are called mast cells. If they are defective and fail to communicate to the brain, the animals in the experiment will unknowingly consume allergens, leading to diarrhea and triggering widespread immune activation and inflammatory reactions in the gastrointestinal tract. So scientists believe that avoiding food is likely an effective defense strategy, and this type of allergic reaction can limit our exposure to harmful stimuli to prevent further damage. In short, if you take a bite of a certain food and feel particularly disgusted and resistant to it, it may be your allergen. However, many foods marked as allergic by the immune system are actually harmless. The author also mentioned that "mast cells have significant conservatism in animal evolution," and they would rather kill harmful substances than let them go. Even if picky eating is not due to allergies, there may be other physiological reasons. Sometimes, our aversion to food does not stem from allergies, but from other congenital or acquired factors. Everyone has varying levels of sensitivity and acceptance towards the smell, taste, and taste of food. For example, the TAS2R38 gene is known as the bitterness gene, and different individuals have different variants of the bitterness gene. People who are bitter sensitive are more inclined to think that many green leafy vegetables are bitter, especially broccoli, cabbage, cabbage and other cruciferous plants. The daily intake of vegetables will also be affected. But in the past, this was actually a survival advantage - it was easier to avoid deadly toxins with bitterness. And genes such as CD36 affect a preference for fat intake. Some people love to eat meat very much, while others don't eat much, and even find pork to have an unacceptable taste. Some people think that coriander has a stinky odor, mainly caused by the OR6A2 gene, which makes people more sensitive to aldehydes, which happens to be the flavor compounds of coriander. There are similar reasons behind the aversion to foods such as shiitake mushrooms, celery, and carrots. In addition, many people have found that when they were young, they hated eating things, but as they grow up, they actually