A moderate amount of onion is not harmful to the body, but it is not suitable for people with gastrointestinal diseases, allergies to onions or eye diseases. 1. gastrointestinal diseases: raw onions are spicy foods, and people with gastrointestinal diseases who eat raw onions are likely to stimulate the mucous membrane of the gastrointestinal tract, causing stomach pain, bloating, acid reflux and other symptoms and aggravating gastrointestinal discomfort; 2. allergies to onions: people who are allergic to onions, eating raw onions may cause local or general rashes, pimples, redness, oozing and other symptoms; 3. For people who are allergic to onions, eating raw onions may cause local or systemic rashes and papules, and patients may suffer from itching, stinging, redness, oozing and other symptoms; 3. For people suffering from eye diseases: raw onions produce volatile gases, and gas stimulation of the eyes may aggravate eye discomfort such as dry eyes and astringent eyes, and eating raw onions is not conducive to recovery from eye diseases. For the rest of the population, eating raw onions properly is good for a balanced diet and can be supplemented with vitamins or trace elements such as calcium, phosphorus and iron, which helps to promote appetite and to some extent has the effect of protecting blood vessels and lowering lipids. However, you should not eat too much at once, because onions are prone to volatile gas, which can easily lead to symptoms of abdominal distension.