You can develop an allergy at any age, to any food, despite having eaten that food without any prior symptoms. While allergies are most common among children (affecting 10 per cent of Aussie and Kiwi infants and only two to four per cent of Aussie and Kiwi adults), a study of 40,000 US adults found almost half of those living with allergies developed them after the age of 18.
So what is an allergy?
An allergy occurs when your immune system overreacts to a normally harmless substance, like food, pollen or dust mites, and determines that the substance is a threat. This then causes a reaction in your body—usually in the form of hives, swelling or breathing symptoms.
Can you develop an allergy as an adult?
Yes you can. As you age, some researchers suggest that your immune system may weaken naturally, which may be why you’re suddenly struggling with that creamy milkshake or feeling itchy after some grilled fish. Certain events (like pregnancy or illness) can also compromise your immune system, which may trigger a new reaction.
Intolerance or allergy?
If your symptoms mainly involve the digestive system (like stomach pain, bloating and gas) a few hours after eating certain foods, this is likely an intolerance. Like your immune system, your digestive system can be affected as you age which may see you develop an intolerance later in life.
What are the symptoms of an allergy?
Unlike an intolerance, an allergy can be serious. Your symptoms would mainly involve an immune system response after eating or coming into contact with an allergen. Symptoms will appear quickly—usually within 20 minutes to 2 hours. They may start off mild, but progress rapidly. The most dangerous reactions (anaphylaxis) involve the respiratory and cardiovascular systems and are extremely serious.
Common allergies and intolerances:
Everyone is born with the enzyme lactase, which helps your body digest the lactose in foods. As you get older and your lactase production declines, you may find yourself suddenly struggling with high lactose dairy products like milk, and experience mild to severe symptoms like bloating, wind and diarrhoea if you have too much.
Gluten is a protein found in wheat, wheat varieties like spelt or farro, and is also found in rye, triticale, oats and barley. Unlike coeliac disease, gluten intolerance is often self-diagnosed as there are no tests to determine gluten sensitivity.
Peanuts and tree nuts are among the most common allergies in adults, along with fish and shellfish. The most common triggers of food allergic reactions in childhood are peanuts, tree nuts, milk and egg.