FOOD FOR THOUGHT
Once you’ve developed a food allergy, is there a way to undo it?
Things you can cancel: a Whatsapp message sent to the person you were talking about (thank you, delete function); a pencilled-in commitment you don’t want to keep; a poorly executed eye flick. But when it comes to food allergies, there’s no physiological U-turn. Adverse reactions to food can broadly be divided into allergies and intolerances. The two share some symptoms, but there’s a key difference: the involvement of the immune system. A food allergy occurs when the immune system mistakenly reacts to a (usually) harmless protein in food. This triggers the release of inflammatory chemicals as the body goes into high alert, causing symptoms such as skin rashes, wheezing and swelling of the lips and tongue, which develop within seconds or minutes. In severe cases, it can lead to anaphylaxis – a serious allergic reaction that can be fatal if not treated quickly.
As for a food intolerance, it doesn’t involve the immune system, and it isn’t life-threatening. It describes any adverse symptom that appears after eating a food – from a headache to a gut symptom, like bloating or diarrhoea. The causes of food intolerance aren’t completely clear; in some cases, it’s down to low levels of an enzyme needed to digest a food (such as with lactose intolerance), but other types are harder to explain, and may involve additives or naturally occurring chemicals in foods.
Allergic? Here’s the deal. The idea that you can ‘outgrow’ an allergy comes from data showing that allergies are more common in early years than they are in adult life; food allergies affect around 6% of children under three, but only about 2% of adults. This is explained by the fact that many childhood allergies are linked with development of tolerance over time. To a certain extent, the type of allergy and its severity will dictate whether you’re likely to grow out of it
– one study found that childhood reactions to milk and eggs were outgrown in around 40% of cases, whereas developing tolerance of peanuts, tree nuts, seafood or shellfish was less common. It’s also possible to develop an allergy at any age, and to something that you’ve previously tolerated. If you do develop an allergy as an adult – or if the allergy persists into adulthood – it’s likely to be lifelong.
So where does that leave you? As it stands, there’s no cure for food allergies. The only treatment is to eliminate the trigger food and have a plan in place in the event that you accidentally consume it. This typically involves antihistamines for mild-to-moderate reactions, and adrenaline for a severe food allergy. Reading labels is a must, too – under EU law (which we’re still bound by, for now), there are 14 known allergens, which must be clearly identified on labels.
It may not be this way forever: studies are currently underway to help us better understand the idea of improving tolerance via exposure to tiny amounts of the allergen in a controlled setting.
But there’s no definitive answer yet, and it’s not something to be undertaken without medical supervision, due to the risk of anaphylaxis. It means that if you think you’ve outgrown an allergy, the only safe way to proceed is to work with your allergy specialist.