The following are the disadvantages of eating too many onions:

1. It is easy to cause eye paste and fever.

2. People with itchy skin, eye diseases, stomach diseases and inflammation of lung and stomach should eat less.

3. Onions are pungent and warm. Patients with fever should eat them carefully.

Taboos for eating onions:

1. Onions and toads: Eating will lead to death. Rescue: the car money is decocted in one or two waters;

second, onion and honey are alike: eating together will hurt eyes, cause eye discomfort, and even lead to blindness. Because honey has the function of clearing away heat, onion contains a variety of bioactive substances. When it meets organic acids and enzymes in honey, it will react chemically, produce toxic substances, and stimulate the gastrointestinal tract, leading to abdominal distension and diarrhea.

3. Onions and shrimps are alike: calcium oxalate is formed to produce stones.

Extended information:

Benefits of eating more onions

1. Sterilization and cold resistance. Onion contains phytoncide, such as allicin, which has strong bactericidal ability and can effectively resist influenza virus and prevent colds. When this phytoncide is excreted through respiratory tract, urinary tract and sweat gland, it can stimulate the secretion of cell pipeline wall in these positions, so it has the functions of eliminating phlegm, diuresis, sweating, bacteriostasis and antisepsis.

2. Preventing cancer Onion's anti-cancer effect comes from its rich selenium and quercetin. Selenium is an antioxidant, which can stimulate human immune response, thus inhibiting the division and growth of cancer cells and reducing the toxicity of carcinogens. Quercetin can inhibit the activity of carcinogenic cells and prevent the growth of cancer cells. According to a survey, people who often eat onions are 25% less likely to suffer from gastric cancer than those who don't, and 3% fewer people die from gastric cancer.

3. Promote gastrointestinal peristalsis and help digestion. Onions contain allicin and have a strong aroma, which often makes people cry because of the pungent smell during processing. It is this special smell that can stimulate gastric acid secretion and increase appetite. Animal experiments have also proved that onion can improve gastrointestinal tension and promote gastrointestinal peristalsis, thus playing an appetizing role, and has obvious effects on anorexia caused by atrophic gastritis, insufficient gastric motility and dyspepsia.

4. Onion is the only plant containing prostaglandin A. Onion is the only known food containing prostaglandin A, and it is a natural blood thinner. Prostaglandin A can dilate blood vessels and reduce blood viscosity, thus lowering blood pressure, reducing peripheral blood vessels, increasing coronary blood flow and preventing thrombosis. It can resist the effect of pressor substances such as catecholamine in human body, and promote the excretion of sodium salt, thus lowering blood pressure. Regular consumption has health care effect on patients with hypertension, hyperlipidemia and cardiovascular and cerebrovascular diseases.

Reference: Functions and Taboos of Onions-People's Daily Online.