Two to three percent of all adults react to certain foods—more than twice that among children. Eating different foods in childhood can cause allergies. There is an EU directive that only 14 ingredients and products derived from them must be declared as possible food allergy triggers in packaged foods. Among them:

10 Foods That Can Cause the Most Severe Allergies
nuts
Many tree nuts, including hazelnuts, hazelnuts, almonds, and pistachios, can cause an antigen-antibody reaction, manifested by coughing, swollen mucous membranes, pustules, or more severe reactions. If so, avoid them at all costs.
Milk
The more often a baby drinks milk, the greater the risk of developing a corresponding allergy or intolerance to lactose. The best prevention for mothers is to breastfeed, as research shows that food intolerances are less common.
soy
Many vegetarians see soy and its products as a substitute for milk or meat – but they also have the potential for allergies, with around half a million Germans suffering from them. Therefore, the use of soy in food must be declared in the EU.
Fish
Although it is very healthy, many children do not like fish, and in addition to the bones, sometimes the unfamiliar taste and “fishy” smell can cause reactions, because fish contains many allergens. So carefully introduce your offspring to fish and fish products – some of them do not tolerate it later.
wheat
Wheat is the most allergenic grain in the world. Wheat and other grains that contain gluten often cause allergies, especially wheat allergy, which is lifelong and cannot be cured. If detected – which, of course, only a doctor can do – the relevant products should be strictly avoided.
Gluten
Cereals containing gluten are consumed in large quantities. Wheat is one of the staple foods worldwide and provides almost 50% of our daily caloric needs. There are various causes of wheat or gluten intolerance; clear identification is often difficult. Along with celiac disease, an autoimmune disease, there is also gluten sensitivity and wheat allergy.
Celery
One of the more common allergies in adulthood is allergy to celery root. Many pollen allergy sufferers are affected here, with symptoms usually mild but in extreme cases can lead to life-threatening anaphylactic shock.
mustard
Mustard allergy is probably the most common spice allergy. Although the chances of getting a mustard allergy are very low, the reactions are often very strong. Mustard allergy usually occurs as a cross-allergy or additional allergy, very rarely as a sole allergy. Most of the known mustard allergens are stable to heat and digestion and are therefore not destroyed during mustard production. These can cause strong reactions.
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