If you didn’t have food allergies as a child, is it possible to develop them as an adult? The short answer is yes. But the reasons why are much more complicated.
Author
Clare Collins
Laureate Professor in Nutrition and Dietetics, University of Newcastle
Preschoolers are about than adults and are more likely to grow out of it as they get older.
It’s hard to get accurate figures on adult food allergy prevalence. The Australian National Allergy Council reports have food allergies. But a US survey suggested as many as were allergic to at least one food, with some developing allergies in adulthood.
What is a food allergy
are immune reactions involving – an antibody that’s central to triggering allergic responses. These are known as “IgE-mediated food allergies”.
Food allergy symptoms that are not mediated by IgE are usually delayed reactions and called .
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 .
IgE-mediated food allergies can be life threatening, so all adults need an developed in consultation with their medical team.
Here are four IgE-mediated food allergies that can occur in adults – from relatively common ones to rare allergies you’ve probably never heard of.
1. Single food allergies
The most in adults in a US survey were to:
- shellfish (2.9%)
- cow’s milk (1.9%)
- peanut (1.8%)
- tree nuts (1.2%)
- fin fish (0.9%) like barramundi, snapper, salmon, cod and perch.
In these adults, about 45% reported reacting to multiple foods.
This compares to : cow’s milk, egg, peanut and soy.
Overall, adult food allergy prevalence appears to be increasing. Compared to and , 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 , childhood-onset food allergies are also more likely to be retained into adulthood. Possible reasons for both 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. Tick-meat allergy
Tick-meat allergy, also called α-Gal syndrome or mammalian meat allergy, is an allergic reaction to galactose-alpha-1,3-galactose, or α-Gal for short.
links between α-Gal syndrome and tick bites in 2009, with cases also reported in the United States, Japan, Europe and South Africa. The about 450,000 Americans .
The α-Gal contains a carbohydrate molecule that is bound to a molecule in .
The IgE-mediated allergy is triggered after repeated bites from ticks or that have bitten those mammals. When tick saliva crosses into your body through the bite, antibodies to α-Gal are produced.
When you subsequently eat foods that contain α-Gal, the allergy is triggered.
These triggering foods include meat (lamb, beef, pork, rabbit, kangaroo), dairy products (yoghurt, cheese, ice-cream, cream), added to gummy foods (jelly, lollies, marshmallow), prescription medications and over-the counter supplements containing gelatin ().
Tick-meat allergy reactions can be hard to recognise because they’re usually delayed, and they can be severe and include anaphylaxis. Allergy , so always discuss management with your doctor.
3. Fruit-pollen allergy
Fruit-pollen allergy, called pollen food allergy syndrome, is an .
In susceptible adults, pollen in the air provokes the production of IgE antibodies to antigens in the pollen, but these antigens are similar to ones found in some fruits, vegetables and herbs. The problem is that triggers an allergic reaction.
The are from birch, cypress, Japanese cedar, , grass, and ragweed. Their pollen can cross-react with , 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 not common. Prevalence depending on the country, but it can be life-threatening. Reactions range from itching or tingling of lips, mouth, tongue and throat, called , to mild , to anaphylaxis.
4. Food-dependent, exercise-induced food allergy
During heavy exercise, the stomach produces less acid than usual and gut permeability increases, meaning that small molecules in your gut are more likely to escape across the membrane into your blood. These include food molecules that trigger an IgE reaction.
If the person already has IgE antibodies to the foods eaten before exercise, then the risk of triggering food allergy reactions is increased. This allergy is called , with symptoms ranging from hives and swelling, to difficulty breathing and anaphylaxis.
wheat, seafood, meat, poultry, egg, milk, nuts, grapes, celery and other foods, which could have been eaten many hours before exercising.
To complicate things even further, allergic 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.
Food-dependent exercise-induced allergy is extremely rare. Surveys have estimated prevalence as between with the highest prevalence between the teenage years to age 35. Those affected often have other allergic conditions such as hay fever, asthma, allergic conjunctivitis and dermatitis.
Allergies are a growing burden
The and health costs due to food allergy is increasing. In the US, this .
Adult food allergy needs to be taken seriously and those with severe symptoms should wear a medical information bracelet or chain and carry an . Concerningly, surveys suggest only with food allergy have an adrenaline pen.
If you have an IgE-mediated food allergy, discuss your management plan with your doctor. You can also find more information at .
Clare Collins AO is a Laureate Professor in Nutrition and Dietetics at the University of Newcastle, NSW and a Hunter Medical Research Institute (HMRI) affiliated researcher. She is a National Health and Medical Research Council (NHMRC) Leadership Fellow and has received research grants from NHMRC, ARC, MRFF, HMRI, Diabetes Australia, Heart Foundation, Bill and Melinda Gates Foundation, nib foundation, Rijk Zwaan Australia, WA Dept. Health, Meat and Livestock Australia, and Greater Charitable Foundation. She has consulted to SHINE Australia, Novo Nordisk, Quality Bakers, the Sax Institute, Dietitians Australia and the ABC. She was a team member conducting systematic reviews to inform the 2013 Australian Dietary Guidelines update, the Heart Foundation evidence reviews on meat and dietary patterns and current Co-Chair of the Guidelines Development Advisory Committee for Clinical Practice Guidelines for Treatment of Obesity.
