Is it feasible to develop food sensitivities in adulthood if one did not have them as a child? Yes, in a nutshell. However, the underlying causes are considerably more intricate.
Preschoolers are about four times more likely to have a food allergy than adults, and they are more likely to grow out of it as they get older.
Accurate data regarding the prevalence of food allergies among adults is exceedingly challenging to obtain. The Australian National Allergy Council reports that one in 50 adults has food allergies. But a US survey suggested as many as one in ten adults were allergic to at least one food, with some developing allergies in adulthood.
What is a dietary allergy?
Food allergies are immune reactions involving immunoglobulin E (IgE), an antibody that’s central to triggering allergic responses. “IgE-mediated dietary allergies” are the term used to describe these.
Food allergy symptoms that are not mediated by IgE are usually delayed reactions called food intolerances or hypersensitivity.
Food allergy symptoms can include hives, swelling, difficulty swallowing, vomiting, throat or chest tightening, trouble breathing, chest pain, rapid heart rate, dizziness, low blood pressure or anaphylaxis.
IgE-mediated food allergies can be life-threatening, so all adults need an action management plan developed in consultation with their medical team.
The following are four IgE-mediated food allergies that can occur in adults, ranging from relatively common to uncommon allergies that you may not have heard of.
1. Food allergies that are specific to
The most common IgE-mediated food allergies in adults in a US survey were to:
- Shellfish (2.9%)
- cow’s milk (1.9%)
- pistachio (1.8%)
- tree seeds (1.2%)
- fin fish (0.9%), including barramundi, snapper, salmon, cod, and perch.
Approximately 45% of these adults reported experiencing reactions to multiple substances.
This compares to most common childhood food allergies: cow’s milk, eggs, peanutsand soy.
In general, it seems that the prevalence of adult food allergies is on the rise. Compared to older surveys published in 2003 and 2004, peanut allergy prevalence has increased about three-fold (from 0.6%), while tree nuts and fin fish roughly doubled (from 0.5% each), with shellfish similar (2.5%).
While new adult-onset food allergies are increasing, childhood-onset food allergies are also more likely to be retained into adulthood. Possible reasons for both include low vitamin D status, lack of immune system challenges due to being overly “clean”, heightened sensitisation due to allergen avoidance, and more frequent antibiotic use.
2. Allergy to ticks and flesh
Tick-meat allergy, also known as α-Gal syndrome or mammalian meat allergy, is an allergic response to galactose-alpha-1,3-galactose, or α-Gal for short.
Australian immunologists first reported links between α-Gal syndrome and tick bites in 2009, with cases also reported in the United States, Japan, Europe and South Africa. The US Centers for Disease Control estimate that about 450,000 Americans could be affected.
α-Gal contains a carbohydrate molecule that is bound to a protein molecule in mammals.
The IgE-mediated allergy is triggered after repeated bites from ticks or chigger mites that have bitten those mammals. Antibodies to α-Gal are generated when tick saliva enters the body through the puncConsu
ming foods that contain -Gal subsequently causes the allergy to develop.-Gal.
These triggering foods include meat (lamb, beef, pork, rabbit, kangaroo), dairy products (yoghurt, cheese, ice-cream, cream), animal-origin gelatin added to gummy foods (jelly, lollies, marshmallow), prescription medications and over-the-counter supplements containing gelatin (some antibiotics, vitamins and other supplements).
Tick-meat allergy reactions can be challenging to identify due to their delayed onset and the potential for severe symptoms, such as anaphylaxis. Allergy organisations produce management guidelines, so always discuss management with your doctor.
3. Allergy to fruit pollen
Fruit-pollen allergy, called pollen food allergy syndrome, is an IgE-mediated allergic reaction.
Pollen in the air induces the production of IgE antibodies in susceptible adults in response to antigens in the pollen. However, these antigens are comparable to those found in certain fruits, vegetables, and botanicals. The problem is that eating those plants triggers an allergic reaction.
The most allergenic tree pollens are from birch, cypress, Japanese cedar, latex, grass, and ragweed. Their pollen can cross-react with fruit and vegetables, including kiwi, banana, mango, avocado, grapes, celery, carrot and potato, and some herbs such as caraway, coriander, fennel, pepper and paprika.
fruit-pollen allergy is uncommon. Prevalence estimates are between 0.03% and 8%, depending on the country, but it can be life-threatening. Reactions range from itching or tingling of lips, mouth, tongue and throat, called oral allergy syndrome, to mild hives and anaphylaxis.
4. exercise-induced food allergy that is food-dependent
The stomach produces less acid than usual and gut permeability increases during heavy exercise, which increases the likelihood of small molecules in your intestine escaping across the membrane and into your bloodstream. These consist of food molecules that induce an IgE response.
The risk of inducing food allergy reactions is elevated if the individual has IgE antibodies to the foods consumed prior to exercising. This allergy is called food-dependent exercise-induced allergy, with symptoms ranging from hives and swelling to difficulty breathing and anaphylaxis.
Common trigger foods include wheat, seafood, meat, poultry, eggs, milk, nuts, grapes, celery and other foods which could have been eaten many hours before exercising.
To complicate things even further, allergic reactions can occur at lower levels of trigger-food exposure and be more severe if the person is simultaneously taking non-steroidal inflammatory medications like aspirin, drinking alcohol or is sleep-deprived.
Exercise-induced allergy that are dependent on food are exceedingly uncommon. Surveys have estimated prevalence as between one and 17 cases per 1,000 people worldwide, with the highest prevalence between the teenage years and age 35. Most individuals who are afflicted also have other allergic conditions, including asthma, allergic conjunctivitis, dermatitis, and hay fever.
Allergies are becoming increasingly burdensome.
The burden on physical health, psychological health and health costs due to food allergy is increasing. In the US, this financial burden was estimated as $24 billion per year.
Adult food allergy need to be taken seriously and those with severe symptoms should wear a medical information bracelet or chain and carry an adrenaline auto-injector pen. Concerningly, surveys suggest only about one in four adults with food allergy has an adrenaline pen.
Consult your physician regarding your management strategy if you suffer from an IgE-mediated food allergy. You can also find more information at Allergy and Anaphylaxis Australia.
