The number of people with food allergies is rising dramatically around the world. In fact, data suggest that peanut allergies have tripled over the past couple of decades.
Food allergy – an abnormal immune response to specific proteins – affects around 1 in 20 children. The most common triggers are egg, cow’s milk, peanut, tree nuts, seafood, soy, fish and wheat.
Most reactions aren’t severe, and many children will outgrow them. But peanut, tree nut, seed and seafood allergies are more likely to cause lifelong problems. And it is possible to develop an allergic reaction to a food that was previously safe to eat.
By adulthood, around 2 in 100 people suffer from food allergies. Symptoms can include swelling around the face, hives or skin rash, stomach pain and vomiting. In some they can cause anaphylaxis, a life-threatening reaction to suspect foods.
Less known allergies
Not everyone with an allergy reacts to the common foods. More than 160 different foods have caused allergic reactions, including meat, sesame seeds, avocados, marshmallows (gelatin), corn, mango, dried fruit, and hot dogs.
Many less common food allergies are caused by oral allergy syndrome (OAS) or pollen-food allergy syndrome. People with OAS react to inhaled allergens like pollen from trees, weeds or grasses, and can develop “cross-reactivity” to foods with similar proteins.
For instance, many people with an allergy to birch and mugwort pollen also react to raw apple, and citrus fruit allergy can cross over to other citrus fruits, grass pollens, Timothy grass, birch and mugwort pollen.
Allergic reactions can impact quality of life. And because of serious and potentially fatal reactions in rare cases, common allergens must be listed on all foods.
Failure to list all ingredients can be tragic, like in the case of 15-year old Natasha Ednan-Laperouse, who died from an allergic reaction to a baguette in 2016. The culprit was sesame seeds, which was not on the ingredient list.
Hospitals and aged care facilities also need to be aware of new laws.
People who are allergic to peanuts (which are legumes, not nuts) might also be allergic to lupin, another type of high protein legume.
Australia’s food standards body, FSANZ, recently changed food labelling laws to require that lupin be declared as an ingredient – even if the food isn’t packaged.
Although lupin is not ordinarily used in Australian foods, it can be found in a range of common food items like bread, bakery products, pasta, sauces, beverages and even meat-based products like burgers and sausages.
Why the rise?
Experts are not sure why food allergies are rising, but environmental influences are most likely.
A probable factor is the human microbiome – the 100 trillion bacteria and other microbes that coexist with us, mainly in our gut. These microbes play crucially important roles in immunity.
A host of modern practices has diluted our microbial diversity, including excessive use of antibiotics and disinfectants, and replacing diverse plant food diets with highly processed foods.
Another intriguing link is the higher incidence of food allergies in areas with less sunlight, suggesting a possible role for vitamin D.
Drawing from these observations, experts advise that we increase our exposure to green spaces, natural environments and sunlight, and regularly eat a broad range of plant foods.
Note that food allergies are different to food sensitivities.
Food sensitivities or intolerances are more prevalent than food allergy. They are not caused by an immune response, so the only way to identify them is by eliminating suspect foods then challenging to see if they produce a reaction.