Onions are a common vegetable that comes in white, yellow and purple-skinned varieties and are rich in nutrients such as potassium, zinc, vitamin C, B vitamins, selenium, in addition to two phytochemicals, quercetin and prostaglandin A. There are advantages and disadvantages to eating onions raw, and daily consumption should be in moderation, according to the individual’s constitution without discomfort. I. Benefits: From the perspective of Chinese medicine, onions have the effect of strengthening the spleen and regulating qi. People who have abdominal distension, loss of appetite or nausea and other conditions eat onions raw appropriately to help relieve symptoms and increase appetite. Onions have a pungent taste and can disperse wind and cold, so eating some raw onions in cold weather can help fight the cold. Onions also have a laxative effect, so eating them raw can promote bowel movements. In addition, the phytochemicals in onions have a lipid-lowering effect. Second, the bad: 1, flatulence, excessive exhaust: onions are prone to volatile gas, if excessive consumption of raw onions, may appear flatulence, excessive exhaust, causing inconvenience to people; 2, acid reflux, heartburn: onion is a stimulating vegetable, raw food for acute or chronic gastritis patients will aggravate the symptoms. In addition, people suffering from eye diseases are not recommended to eat onions, especially raw onions tend to stimulate the tear ducts, leading to recurrence or attacks of eye diseases.