T o someone from Generation X or older, it often feels like food allergies are much more common today than…
T o someone from Generation X or older, it often feels like food allergies are much more common today than in their adolescents. While they remember that they are rare or nonexistent during school days, their own children will have classmates with allergies or they may have one.
According to the Food Standards Agency, estimates estimate that approximately 5-8% of children and 1
-2% of adults are affected by food allergies in Britain. The latest headlines on fatal allergic reactions, as for two Pret a Manger customers, increase the impression that food allergies are more common.
So is the impression that they increase correctly and what causes it? And what has gone wrong with our bodies that we can be killed by something that seems unlikely to be a sesame seed?
Since 1906, when the word “allergy” was used for the first time, the number of victims has been climbing. Asthma has probably always been a problem, but if it’s something old, it’s also unusually rare.
Everyone does it: chicken fever seems to become increasingly common the more distant we grow from nature. Photography: Alamy Stock Photo
Right pest was first documented in the 19th century. Doctor John Bostock was one of the first to collect data and when he shed the country to find hay fever, his overall case of laughing was small for a modern audience: 28.
Morell Mackenzie, a British doctor in the 1880s, noted that because “summer sneeing goes hand in hand with the culture, we may influence that the higher we rise in the intellectual scale, the more the trend is developed.” From the outset, allergies were linked to those who were more distant from rural growth.
Between 2007 and 1980, like the 2007 studies, Time Trends in Allergic Disorders in Britain and 50 years of asthma describes the numbers that fought with hay fever, eczema and asthma “increased significantly.” Conversely, the air (according to Defra) has become smaller, no more polluted. Even with fewer allergens, our symptoms appear to be wider.
Before the 1990s, peanut allergy was so rare that barely any data on it was collected. In an article in 2015 in Journal of Allergy and Clinical Immunology Paul J Turner noted that although infections to hospitalized anaphylaxis increased between 1992 and 2012 by 615%, the incidence of fatal anaphylaxis did not occur. Turner and his colleagues believed that “increased awareness of the diagnosis, changing behavior patterns of patients and carers” may be contributing factors. Although peanut allergy is much more common, its associated deaths have not increased.
Prof Katie Allen of the Murdoch Children’s Research Institute in Melbourne, Australia, 10 years in HealthNuts, a study that tracks food allergies in 5,300 Australian children, explains that she was “amazed” by her first results. When the trial began, they were expecting to find around one of 20 of their one-year subjects that tested positive for nutrient energy, but they found twice. Everyone explains: “The food allergy epidemic has happened after asthma / oesophagus. We call it the second epidemic of allergic disease.”
Genetic studies are about to eliminate the relationship between our DNA and allergies. Major case studies of, for example, 50,000 eczema diseases or 60,000 of those with hips show that there may be as few as 20 to 40 of our 20,000 genes that form the genetic architecture of allergy. Dr. Manuel Ferreira, a specialist in asthma generation at the QIMR Berghofer Medical Research Institute in Brisbane, Australia, explains that he and his team in a new study to be published have discovered that the genetic risk factors for food allergy overlap significantly with those for other allergic diseases such as asthma and hips. “
Generals play a role then, but the fact that we will have transported similar DNA for thousands of years without being so allergic suggests that the environment is a key factor. Dr. Paul Gray, Personal Specialist in Pediatric Immunology and allergy at Sydney Children’s Hospital explains: “People’s network genetics change little over time, so epidemics are driven by non-genetic changes.”
Natasha Ednan-Laperouse, who died after eating a Pret a Manger sandwich containing sesame, as she was allergic to in July 2016. Fotog rafi: Ian McIlgorm
While the symptoms of different conditions vary in kind and seriousness, what binds these annoying together is that they are all overreactions of the body’s immune system when exposed to a usually harmless trigger. Gray explains that allergy is “an accident of immune recognition that leads to an aggressive response to something abroad but innocent, with detrimental consequences for the host”.
Why there are more food allergies today knows no exact reason, but experts now believe that there are three contributing factors.
The first is the delayed introduction of allergens. For several years, allergy specialists have recommended that infants avoid the consumption of potentially allergenic foods. Not only was this incorrect, but it may have played a part in driving the food allergy epidemic as we see today.
Prof Gideon Failure at King’s College London, Leading Investigator to Learn Early About Peanut Allergy (LEAP Study) found that “Of the peanut-born children, 17% developed peanut allergy at five years of age. only 3% of the children randomized to eat peanut depth developed allergy at the age of five. “The children participating in the trial already had severe eczema and / or egg allergy (both strong predators for allergy).  The introduction of potential allergens while transferring infants into solids seems like a good idea. However, it is a brave thing like a parent to risk exposure. Dr Gray explains: “Most parents begin to realize that early food intake is crucial, but many do not feel brave enough to do it at home and the resources within the hospital are not available for hospitalization. It has to be solved.”
The The second contributing factor for food allergy (and allergy more generally) includes the human microbiomics and the microorganisms that are our “old friends”. The body learns about its environment after it is born by contacting a range of substances, ranging from the bacteria that we dirt into as we travel into the birth canal of the breast milk we feed on. Then, proximity to animals and natural environments, it is more likely that we will be exposed to a wide range of bacterial life, in the air, on the soil and in the diet. All these aids fill our bodies, but especially our intestines, with microbiota. This is an important part of being human that the microbiot exceeds us within our own bodies: the people consist of something between 27 and 37 cells. but we carry about 100th of these organisms within us. We are surprisingly complex ecosystems. The “old friend” or the hygiene hypothesis postulates that modern life has jeopardized our microbiome: our immune system can now categorically categorize harmless substances as a threat.
The complexity of our microbiomes has led to disturbing the conclusions of the “old friends” hypothesis. A recent systematic review (Hygiene hypothesis in Asthma Development: Hygiene to Blame?) Required “caution” given the general hypothesis to explain the complexity of a disease such as asthma and the ways it presents in different parts of the world.
Yet, imbalances in gutecology have been strongly linked to allergies.
As an adult, the ecology of our intestine is well developed, but we can still help to influence it. Prof Graham Rook, an immunologist at University College London’s Center for Clinical Microbiology, explains that “the important issue is contact with the green space and the natural environment and prevention of antibiotics and of things that limit the transmission of mother microbiota to the baby.” And we need a varied diet with many different fruits and vegetables, as these things maintain the biodiversity of microbiotas. “
Probiotics stimulate the growth of microbiota. The fact that people suffering from severe allergies have significantly less varied (and less dense) intestinal flora suggest that the future of allergy can be in probiotic interventions. But you can not just go to the supermarket and take a probiotic drink from the shelf and expect it to be effective. A mass-produced probiotic is about as successful as mass-produced false teeth. Researchers are working on personal probiotic therapies but they are many years from being safe and effective treatment.
Stunning investigations such as hunting for allergy origin and native immunity and asthma risk have compared genetically homogenous groups with distinctive lifestyles – the urbanized Finnish and Russian populations in Karelia, and children in traditional Amish and more industrialized Hutterite farms in the United States – and how they show great differences in the occurrence of allergy. This science shows that it is the distance from and lack of exposure to natural environments that conduct allergy epidemic in modern life.
Packaged with goodness? Lack of vitamin D can cause allergic reaction to eggs. Photography: Incense / Getty Images / Glow RM
The final third driver of food allergy, which is also linked to city life, is associated with the curious fact that there is an approximate geographical spread of food allergy. Researchers have started to notice that the presence of food allergy has a tendency to adapt to the geographic availability of sunlight. In a series of papers and studies, Professor Carlos Camargo of the United States and Prof Katie Allen and her colleagues in Australia have investigated how lack of exposure to sunlight – and a consequent vitamin D deficiency – can make infants three times more likely to have an allergy to an egg and one dizziness 11 times greater risk of peanut allergy.
City life makes it harder for us to regularly be exposed to natural environments. We also spend more time indoors, which makes vitamin D deficiency more common throughout the population, but especially in children. In the United Kingdom, parents are advised to “cover exposed parts of your child’s skin with sunscreen, even on possible or possible days”.
As we grow up in increasing numbers, the green spaces and natural environments between us are squeezed and bring countless opportunities for our immune system to learn about the world around us and to have substantial access to sunlight. And although there are many factors involved, the levels of urbanization appear to be one of the strongest predictors of the presence of allergy in a population, both historically and in the future.  • Primate Change: How The World We Made Remaking Us by Vybarr Cregan-Reid published by Octopus (£ 16.99). To order a copy for 14,61 kr, go to guardianbookshop.com or call 0330 333 684. Free UK p & p over $ 10, online order only. Phone Order My P & P at $ 1.99