The incidence of food allergies has increased rapidly in the last 20 years. However, no one knows why. The latest theory suggests that chemical compounds called dichlorophenols, such as found in purified tap water, pesticides and disinfectants, may be responsible for this.
Whenever Natasha Salmon finds herself in a room with even the smallest bowl of peanuts, she immediately begins to find it hard to breathe. Once, when she tasted a dish with satay sauce, after a few bites she was breathless. “It was five or six years ago in a Thai restaurant,” he recalls. – I ate some satay [made with peanuts] by accident. After a few seconds, my face, mouth and airways swelled horribly. I immediately used the adrenaline auto-injector that I carry with me in case of a sudden allergic reaction. But my friends had to call an ambulance anyway, and I was sick all week.
Natasha’s allergy to peanuts first appeared when she was only five years old, and as time went on, his symptoms became more and more severe. A 21-year-old journalism student from Farnham, Surrey, aged XNUMX, she became allergic to raw fruit and vegetables. Recently, she has not even been able to eat salads with vegetables such as lettuce, celery and cucumber – because her lips, cheeks and larynx are swelling right away.
“I can’t even describe how much I miss the fresh, crunchy Golden Delicious apples,” sighs Natasha. – In winter, my allergies are less so, so I indulge myself and eat only the peel of the apple. I manage somehow, take antihistamines and lubricate my lips with petroleum jelly. But it cannot be denied that my allergy is getting worse year by year. My immunologist cannot explain it, although he thinks it may be related to hay fever. I have to hold on somehow and hope that my condition will go away on its own.
The incidence of food allergies has increased rapidly in the last 20 years. It is estimated that between 1% and 2% of adults and 4% to 6% of children suffer from them. The number of minors admitted to hospital for food-related anaphylactic shock (a life-threatening allergic reaction) has increased sevenfold since 1990 – but no one knows why.
The latest theory, presented in the latest issue of the Annals of Allergy, Asthma and Immunology, suggests that chemicals called dichlorophenols may be responsible for this. American scientists studying food allergies in more than 2 people have found that patients with the highest concentration of dichlorophenols in their urine have an 80 percent increased risk of food allergy. Researchers hypothesized that the antibacterial properties of dichlorophenols – found in purified tap water, pesticides and disinfectants – adversely affect the gut microflora that protects us from food allergies.
So should we eat only organic fruit and vegetables and replace tap water with bottled water? Let’s hold off for now, advises Jonathan Brostoff, professor of allergology and public health at King’s College London. He points out that the authors of the analysis made several mistakes, for example classifying patients as allergic on the basis of a blood test, the reliability of which is only 50 percent. – The diagnosis of food allergy is extremely complicated and difficult without examining the patient in a clinical setting – emphasizes Brostoff. – Moreover, the report did not provide information on how many people with the lowest levels of dichlorophenols were diagnosed with food allergies – he adds. – It is possible that these substances upset the body’s immune function and increase the risk of sensitization, but much more data is needed to establish a cause-and-effect relationship.
Even if such a dependency was discovered, tap water in the UK is completely safe, says Professor Jeni Colbourne, head of the UK’s Drinking Water Quality Inspectorate. By comparison, the US uses higher doses of chlorine and the control standards are less stringent. Colbourne also explains that, contrary to popular belief, dichlorophenols are not used in water treatment. These are by-products that are formed when the chlorination process reacts with phenols, industrial toxic substances found in untreated water. (…)
Dichlorophenols are also formed as a by-product of the popular antibacterial and fungicidal agent triclosan (a component of many everyday products, including toothpaste). However, most of these compounds can be found not in water, but in cleaning agents, plastic utensils and kitchen containers, and in pesticide residues in food. (…)
The reason for the increase in the incidence of food (and other) allergies remains a mystery. Another well-known theory is the so-called hygiene hypothesis that our obsession with cleanliness keeps children from being exposed to the bacteria that support the proper development of the immune system. Another unproven theory is that the allergy epidemic is the result of changes in the diet of Westerners who eat more and more processed foods and less fresh fruit and vegetables.
“Nobody knows the answer, although the hygiene hypothesis still has the most support,” says Kristian Bravin, a Leicester dietitian. – Increased social awareness and better diagnostics also play an important role. According to Bravin, as many as 20 percent of people suspect that they suffer from food allergies or intolerances, when in reality these ailments are much less common.
Some experts argue that the government guidelines introduced in the 90s may have contributed to the increase in the scale of food allergies. Parents were advised not to give young children peanuts, allegedly because consumption of potential allergens at such a young age could weaken the undeveloped immune system. Everything indicates that it is in fact quite the opposite, emphasizes Professor Brostoff.
These guidelines were quietly withdrawn in 2009, a year after the publication of a large-scale, groundbreaking study that found that British Jewish children are ten times more likely to be allergic to peanuts than their Israeli peers. Most children in this country eat peanut proteins in their first year of life, even in the popular Bamba crisps.
“At this point, no one knows what to recommend to people anymore,” Bravin admits. Scientists are currently conducting a series of studies to help develop the best strategy to counter food allergies. One project is an Anglo-American study involving 640 children, led by Professor Gideon Lack, a pediatrician and immunologist working at Guy’s and St Thomas’ and King’s College hospitals, and co-author of the discovery on allergies in young Jews. The new analysis is expected to show whether regular feeding of peanuts to children in the first three years of life reduces the risk of sensitization. Other researchers at King’s College will see if introducing six allergenic foods into the diet of three-month-old babies will prove beneficial to their health.
Brostoff believes that the best way to reduce the risk of food allergies in young children is to gradually include potential allergens – not only peanuts, but also cow’s milk, eggs and fish.
“The gut lining is the immune system’s most powerful weapon,” the professor points out. – I always tell parents that it is worth introducing new foods as early as possible, when the gut is more flexible and easier to adapt. Giving a young child a variety of products can increase intestinal tolerance, a factor that plays a much greater role than the presence of any chemicals in the environment.
Despite the extremely restrictive diet, Natasha Salmon can still enjoy her favorite dishes. “Luckily, I love carbs,” he says. – There are no nuts in Italian and Spanish cuisine, and paellas and pastas are what I like the most.
Food allergies – causes and symptoms
A food allergy is an excessive immune response caused by proteins found in certain foods. The most common type of allergy is caused by immunoglobulin E (IgE), an antibody that secretes a number of chemicals, including histamine. Histamine usually causes symptoms such as swelling of the veins and skin, itching, heavy breathing, and a build-up of phlegm. Other non-IgE-dependent food allergies may be associated with symptoms such as heartburn, indigestion and eczema. A patient’s allergy can be diagnosed by taking a series of blood and skin tests, and by eliminating individual foods from the diet.
Children are most often allergic to eggs, milk, soy, wheat and peanuts. Many young people “outgrow” the allergy to milk and eggs, but the allergy to peanuts most often persists for the rest of their lives. In adults, allergies to certain fruits and vegetables, shellfish, nuts (including walnuts, almonds and peanuts) and fish are the most common.
Currently, it is recommended that products containing allergens not be given to infants under six months of age. If there is a family history of allergies, babies should be exclusively breastfed for the first six months (if possible).
Food allergy is not the same as food intolerance, which is generally accompanied by symptoms such as pain and gas, usually occurring 12 to 36 hours after eating.