On the island of Ireland, the three most common forms of food hypersensitivity are food allergy, food intolerance and coeliac disease.
A food sensitivity is a bad reaction to a food that is otherwise safe to eat.
You can be allergic or intolerant to more than one food
It is possible to have allergies to more than one thing. It is also possible to be intolerant to certain things and allergic to other things. It all depends on how similar the offending chemicals are in the food or pollen or whatever material you are allergic to. This is called cross-reactivity: if you have an allergy to a food, you can react to another substance (not necessarily another food) if it contains a protein like the protein that causes your allergy in the first place. For example,
- Cross-reactivity may result in someone who is allergic to prawns also being allergic to shrimps, crab and lobster.
- Quite often peanut allergic people are also allergic to lupin flour.
- Hen’s egg is cross-reactive with other eggs.
- Cow’s milk is cross-reactive with milk from goats and sheep.
- Someone with a wheat allergy can also be allergic to rye and grass pollen.
Some cross reactions are less obvious:
- An allergy to house dust mites may lead to an allergy to shellfish (molluscs and crustaceans).
- An allergy to latex rubber increases your risk of becoming allergic to certain fruits and vegetables.
- Those who are allergic to pollen, particularly birch or olive pollen, may develop allergic symptoms when they eat hazelnuts, apple, cherries, pears or carrots.
Food allergy and intolerance are not forms of food poisoning
In a case of food poisoning, someone has become ill due to eating a food that is contaminated with harmful bacteria or toxins. Contaminated food should not be eaten by anyone.
With a food allergy or intolerance, the offending food is safe to eat for the majority of people. However, it triggers an unhealthy reaction in some people. For example, peanuts are nutritious and tasty foods enjoyed by a great many people but for someone with a peanut allergy they can be very dangerous.
How to know if you have a food allergy or food intolerance
It is very important that a food hypersensitivity (food allergy, food intolerance or coeliac disease) is diagnosed medically. Self-diagnosis is extremely risky as many of the symptoms associated with these conditions are common to a number of other illnesses. It is important to remember that food poisoning from eating contaminated food, and food aversion – where someone just doesn’t like a particular food (but will not be ill if they eat it) – are not food hypersensitivities.
If you diagnose yourself, you may cut out of your diet certain foods that are safe and nutritious while at the same time continuing to include foods that may be risky. If you think you have a food hypersensitivity, you need to talk to your General Practitioner.
Is there a medical cure for food allergy or intolerance?
So far there is no cure or ‘magic bullet’ for a food allergy or intolerance. That said, a lot of research has been done into what causes allergies or intolerances, allowing us to better understand them and hope for a medical cure in the future. For the moment, managing the conditions means strictly avoiding the foods that cause them. Treatment for food allergies usually involves antihistamines for a mild reaction, and adrenaline for a severe reaction.