Why are allergies so prevalent in children and how can they be prevented?

Why is your baby vomiting industrial milk? Why can’t your child put his nose out in May without tears in his eyes? And why is your daughter out of breath as she sleeps in a country house? Today, respiratory allergies and food affect many children. And more and more. The causes of these allergic diseases seem multiple and complex. It therefore seems essential to understand them in order to prevent the explosion.

Allergies have gone from 3.8% to 30% of the world’s population in five years

There is normally no reason why a naked human cannot bear grass or peanuts from birth. It is an excessive immune reaction that explains that the nose is flowing, the eyes are red, sneezing, swelling, scratching… “Allergies are the 4th most common chronic disease according to the World Health Organization, introduced by Karine Adel-Patient, a researcher at the Institute for Public Research for the Coherent and Sustainable Development of Agriculture, Food and the Environment (INRAe). And the WHO predicts that 50% of the world’s population will suffer from allergies by 2050. ”Because these diseases, respiratory or food, have been on the rise for thirty years. The WHO estimates that 30% of the world’s population is now affected by an allergic disease, compared with 3.8% in 1968.

“Allergies are becoming more common and severe in children”

In France, the number of people suffering from an allergy has doubled in twenty years, according to the associations. Without sparing the children. Although it is difficult to compare surveys that do not always have the same subject of study – for example, a single food or a single pollen – or the same population studied, several international and French studies have something to warn. The Elfe study, which follows 15,000 French children born in 2011, reveals that 6% of them have developed a food allergy, and among them, 20% have multiple allergies. “Allergies are becoming more common and severe in children,” said Karine Adel-Patient. Asthma [80 % des asthmes sont allergiques] reach 4 million French people, a third of whom are children. Similarly, 6 to 8% of children suffer from food allergies… compared to 2 to 4% of adults. »

This concern is confirmed by Madeleine Epstein, an allergist in Paris and vice-president of the allergists’ union (Syfal). “Objectively, there are more and more allergic children. When I became an allergist in the 1980s, I was barely talking about food allergies. In fact, it was with children that we discovered the allergy to peanuts, milk … Today, the most common food allergic reactions in their homes regarding peanuts, nuts, eggs and milk. With a significant impact on their daily lives. “Allergies are the leading cause of absenteeism,” says Karine Adel-Patient. A child allergic to bare milk will not be able to participate in birthday snacks. »

Hints to explain this increase in allergies

Is this the ubiquity of plastic in our environment? Chemical compounds in baby bottles? Industrial food? The clothes? Air pollution? The causes remain mysterious. “It’s multifactorial,” warns the allergist. Immune system dysfunction. Who orders it? The microbiota. Or, changes in diet and the environment influence it. Pe also knows that the use of antibiotics changes it, or we notice more allergies in children who have received many small antibiotics. »

Piste also leads to global warming. Plants and trees grow where the population has never been exposed to this kind of pollen. “Pollution acts on pollens by making them more allergenic, and on the respiratory mucosa by making them more fragile.” In addition, it can alter the genome and make the propensity to be allergic hereditary. It works in every way, it’s great! Dr. Madeleine Epstein jokes.

What explains the growing importance of allergic children is that the genetic component is important. “In the global population, a child between 5 and 10% is at risk of developing an allergy, more than 30 to 40% if one of his parents is allergic, and up to 60% if his two parents are allergic,” he said. Karine Adel-Patient. Logically, if more and more adults develop allergies and become parents, the proportion of allergic children rises.

How to determine the factors of these allergies and improve prevention?

To go further and understand the triggering factors, Karine Adel-Patient’s team at INRAe has launched a research project on the link between food and childhood allergies. For the past five years, with the support of the Medical Research Foundation (FRM), they have been trying to determine which chemical contaminants, ingested by the mother during pregnancy and breastfeeding, could be responsible. Researchers rely on two major French epidemiological studies: Elf, which has already been discussed, and Eden, which looks at the determinants of a child’s development and health. “They follow mothers during pregnancy to find out about their diet and lifestyle,” she said. Then samples of milk, hair, and urine are taken at the maternity ward. Then their children are followed for ten or twenty years, especially to see if they develop allergies. Then we will cross these data with those of the National Agency for National Food Safety (Anses), which has published levels of contamination for 400 foods covering 90% of the average French diet. »

Complementary approach: ekipa is interested in meconium, the baby’s first stool. “They accumulate during the last six months of pregnancy. History examines what the fetus ingested via the placenta. Finally, researchers are testing certain contaminants on mice to see if their offspring are developing allergies. The objective? “We hope to be able to highlight the precise dangerous contaminants and help put in place a prevention policy to curb the allergy epidemic,” concludes Karine Adel-Patient. In the meantime, what can pregnant mothers do? The researcher advises them to “eat a variety of seasonal fruits and vegetables, as natural as possible, and to avoid anything that is processed and packaged.” Hoping to have much more specific recommendations in a decade or so.

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