Experts warn: food allergens in life, we should pay attention to

In recent years, the number of people with food allergies has increased rapidly. The survey found that about 8% of children and 4% of adults have allergic symptoms to one or more kinds of food. How do allergic reactions occur? What harm does it do to human body? What are the common food allergens? On April 18, 2019, the 20th issue of "Journal Medium Benefit" scientific papers sponsored by the Science Media Center of the Chinese Institute of Popular Sciences promoted Salon's "Food Allergens in Life, Attention" special event was held at the Beijing Academy of Food Sciences. Four experts from the fields of medicine and nutrition were invited to share the latest progress of food allergens research on the spot. Ma Tingting, deputy director and deputy chief physician of allergy Department of Beijing Century Temple Hospital, first combined with her clinical experience and research, made a scientific popularization on the causes and hazards of allergic diseases, the natural course of allergic diseases, common allergens and their types, and the treatment of allergic diseases.

Dr. Mattington introduced that allergic diseases are one of the most common chronic diseases in the world. Allergic diseases have high morbidity, complex etiology, multiple organs involved, seriously affecting the quality of life, and need long-term control. Allergens mainly include food allergens, inhalation allergens (dust mites, pollen, animal hair, etc.), allergens and contact allergens (hair dyes, etc.). The key to prevent and treat allergic diseases is to identify allergens. In the course of treatment, attention should be paid to symptomatic treatment, desensitization treatment and avoidance of contact with allergens. Food allergy refers to the abnormal immune response of the body to food after it enters the human body, which leads to the disorder of physiological function and/or tissue damage, and then causes a series of clinical symptoms. Common food allergens are milk, eggs, peanuts, soybeans, wheat, nuts, fish, shrimp, crab, shellfish, etc. The prevalence of food allergy in children is higher than that in adults due to poor gastrointestinal barrier, low digestive enzyme activity, low gastric acidity and immature immune system. Allergic diseases have a natural course of disease. Some infants and young children with allergies can improve themselves after the age of 3-6. Food allergies are most commonly caused by ingestion, but there are also food allergies caused by exposure and inhalation. The clinical manifestations of food allergy include oral symptoms (lip swelling, etc.), respiratory symptoms (dyspnea, etc.), gastrointestinal symptoms (diarrhea, bloody stools, etc.), skin symptoms (eczema, dermatitis, etc.). For food allergy, there is no oral desensitization therapy in China. Therefore, for patients who have a definite allergenic food, they should abstain from the food and all foods containing the food ingredients. Xue Wentong, professor of the School of Food Science and Nutrition Engineering, China Agricultural University and director of the China-Japan Food Research Center, China Agricultural University, shared the topic "Changes of food allergens in human digestive process". He points out that 95% of allergens in food are protein. In the process of food processing, fat, sugar and other components can interact with protein. Therefore, the process affects food sensitization. For example, the sensitization of boiled peanuts is lower than that of fried peanuts, while that of fried peanuts is lower than that of baked peanuts. At the same time, the protein will be decomposed by gastric acid and various digestive enzymes when it enters the human body. The sufficiency of decomposition affects its sensitization, and the sufficiency of decomposition can greatly reduce the sensitization. Therefore, in order to prevent food allergies, besides avoiding food allergens, we should also protect gastrointestinal health and maintain good digestive function. In addition, from the perspective of prevention, adding some protein in infant diet properly can prevent allergies to a certain extent. Increasing food diversity in pregnant and lactating women is helpful to enhance offspring's resistance to allergies. Teacher Tong Ping, an associate researcher in the State Key Laboratory of Food Science and Technology of Nanchang University, shared the topic of "egg allergy and processing control". Egg is an excellent food with high nutritional value and easy absorption, but it is also one of the eight common food allergens. According to the data of food allergy screening conducted by Children's Hospital Affiliated to Chongqing Medical University in 2012, eggs are the first food allergy among infants and children in China. The incidence of egg allergy is so high, but in daily life, it is seldom heard that children are allergic to eggs, mainly because the symptoms of egg allergy are very similar to those of other allergic diseases, and easy to be ignored. The common symptoms of egg allergy include rash, edema, rubella, urticaria, nausea, abdominal pain, diarrhea, cough, asthma, etc. If you have other allergic diseases, the degree of allergy may be increased after eggs are ingested. In addition, egg allergy is often accompanied by eosinophilic esophagitis. Attention to vitamin D supplementation in children aged 0-2 is helpful to prevent egg allergy. For the treatment of egg allergy, strict avoidance was used in the past, but now avoidance + induction of tolerance is used. Allergen proteins bind to antibodies only with specific surface structures (epitopes), which can change the occurrence of allergies. Hence, eggs that are fully heated or otherwise processed are being studied to establish egg immune tolerance.