Preventing food allergies means strictly avoiding them?
Writing | Jun Ling
Source | “Medical Community” Public Account
The prevalence of food allergy in the Chinese population increased by 60% in 10 years?
On August 26, the CCDC Weekly published a series of research papers on food allergies in Chinese, and conducted a detailed analysis of food allergies among different groups of people in my country. .
One of the papers showed that among 20 common foods, subjects reported a self-reported allergy rate of 4.3%, compared to 6.15% for children alone. Another meta-analysis found that the prevalence of food allergy in my country was 8% from 2009 to 2018, higher than the 5% from 1999 to 2008, indicating that the prevalence of food allergy in China is increasing.
The study said that the Codex Alimentarius Commission has defined eight major food allergens, but their prevalence in China is not clear. Further improvement of the epidemiological data of local food allergies can help Provide scientific evidence for the development of indigenous control measures.
Rise in prevalence of food allergy in China
This research series consists of 5 papers.
In a multicenter, cross-sectional epidemiological survey, researchers randomly recruited 11,935 adults and 8,856 children in Jiangxi Province for food allergy screening.
Results showed that of all participants, 5.8% reported adverse food events and 4.3% reported food allergies. Among them, the incidence of food allergy in children aged 6-11 (6.15%) was significantly higher than that in adults (2.9%).
In another meta-analysis study, researchers retrieved 24 cross-sectional studies on the epidemiology of food allergy in China from 2000 to 2021, covering a total of 138,740 adults and Children, the statistics found:
The prevalence of self-reported food allergy was 12% and hospital-diagnosed food allergy was 5%;
The prevalence of food allergy in men and women is 9% and 10%, respectively;
Children aged 4-17 had the highest prevalence of food allergy at 10%, followed by adults at 7% and infants at 6%.
The results also show that the prevalence of food allergies in 2009-2018 was 8%, a 60% increase from the previous 10 years (5%), indicating that the prevalence of food allergies in China is on the rise trend.
Professor Luo Xiaoqun, director of the Allergy Department of Huashan Hospital Affiliated to Fudan University, told the “medical community” that the increase in food allergy rates is not unique to China, but has a corresponding trend in the world. Changes in dietary structure are related to increased detection rates due to increased health awareness and diagnostic ability.
Which foods cause allergies?
The series of studies also counted the proportion of different types of food in the total number of food allergy patients in China.
Researchers surveyed 2,997 elementary school students in 5 schools in Nanchang City, Jiangxi Province, and found that the prevalence of self-reported food allergies was 4.9%, and the top three allergens were shrimp (28.1%), mangoes (22.6%) and shellfish (18.5%).
In general, according to an epidemiological survey in Jiangxi Province (20,971 people in total), the 8 most common allergenic foods are shrimp, mango, shellfish, eggs, fish, and beef. , milk and mutton, the prevalence rates were 1.95%, 1.22%, 1.07%, 0.68%, 0.49%, 0.35%, 0.34% and 0.25%, respectively.
In a meta-analysis study covering data of more than 130,000 people across the country, it was found that:
27% of people with allergies are allergic to eggs and crabs, and among minors, babies aged 0-3 are more likely to be allergic to eggs;
22% of people with allergies are allergic to cow’s milk, and infants aged 0-3 are more likely to be allergic to cow’s milk than any other food allergen;
16% were allergic to shrimp and 15% were allergic to fish;
5% of people with allergies are allergic to meat.
Researchers also found that 16% of people’s allergies were fruit, with mangoes accounting for the highest proportion, accounting for 15% of food allergies. In addition, children/teens aged 4-17 years were more likely to develop fruit allergy than infants aged 0-3 years.
Research points out that peanut allergy is the most common in the United States and Europe, but it is not a common food allergy in China, this studyAmong them, only 4% were allergic to peanuts. In a survey of primary school students in Nanchang, peanuts only ranked 8th in the list of allergic foods.
Correspondingly, no fruit is listed as an allergen to be identified by the International Codex Alimentarius Commission – fruit allergy is not common in the West, but mango allergy accounts for this time in China 15% of the food allergens in the study.
Food allergies = strict fasting?
According to the definition of the International Codex Alimentarius Commission, the “eight major” allergenic food sources are: milk, eggs, peanuts, tree nuts, fish, crustacean shellfish, wheat and soybeans, but currently China There is currently no list of priority allergy foods based on the actual situation of the local population, and the overall reference is to international standards.
Professor Luo Xiaoqun told the “medical community” that for children suspected of immediate food allergy, the allergen is generally determined through the corresponding rapid diagnostic kit. But such kits are often imported products, and although they cover common allergic foods, they are not “customized” according to Chinese characteristics, such as mangoes not included.
As for allergies, it is generally believed that there is no cure at present, and the only strategy to prevent food allergies is to strictly avoid ingestion. Professor Luo Xiaoqun believes that this often leads to two extremes, “either parents don’t pay attention to food allergies at all, or after seeing a doctor, doctors give ‘strict avoidance’ medical advice to all children suspected of food allergies.”< /p>
“Not all food allergies mean strict fasting.” Professor Luo Xiaoqun said, “Many times, we need to induce tolerance on the immunological mechanism to strengthen the human body. Adaptation to the outside world.”
One example is that peanuts are a common food allergen in Europe and the United States, but the National Institute of Allergy and Infectious Diseases (NIAID) encourages infants at moderate risk of allergy to consume peanuts early . The “Peanut Ingestion to Prevent Peanut Allergy” guideline also states that early consumption of peanuts (in an infant-safe form) reduces the risk of allergy in infants as they age.
“If the allergy symptoms of the children are more serious, we recommend parents to avoid foods with high allergies in the short term.” Professor Luo Xiaoqun said, “If the clinical symptoms are not serious, , our suggestion may be to eat small amounts and slowly induce food tolerance.”
But this approach is not universal. For example, guidelines do not recommend deliberately introducing another common allergy to eggs in early infancy. At the same time, should mango be included in allergen screening? Or add other foods? Because of the complex process of updating the kits, this is not something that can be determined with just a few studies.
Therefore, in the opinion of Professor Luo Xiaoqun, the series of studies released this time are equivalent to “starting a head”. In the past, China’s food allergy prevention and control system was not perfect. “In the future, whether it is to formulate relevant guidelines or consensus, or to update and popularize new test kits, local epidemiological data with sufficient evidence is a prerequisite.” Professor Luo Xiaoqun said.
Professor Luo Xiaoqun also suggested that at present, for parents, if the child has obvious allergic manifestations, such as rash, etc., or the parents are allergic, they can take the initiative to go to the relevant medical institutions Get screened for food allergens and follow your doctor’s medical advice.
Source: Medicine
Editor in charge: Tian Dongliang
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