Most people with asthma do not have to follow a special diet. But, in some cases, certain foods, including cow's milk, eggs, fish, shellfish, yeast products, nuts, and some food colourings and preservatives, can make symptoms worse.
If you think you have a food allergy, contact your doctor or asthma nurse for further advice.
What is a food allergy?
An allergic reaction occurs when the body's immune system reacts abnormally to a harmless substance, such as food.
How are food allergies diagnosed and treated?
- Symptoms of food allergies can vary widely. You may get symptoms in your mouth (swelling or tingling), gut (vomiting, diarrhoea), skin (rash, swelling of face) or in your chest (wheezing, shortness of breath).
- Your asthma may flare up.
- If you feel you or your child has a food allergy then you should contact your doctor. They may refer you to a specialist or an allergy clinic for testing.
- There is no reliable medicine for food allergies. The only treatment is avoiding the offending food.
What foods can trigger allergic reactions?
- Foods that can trigger asthma by way of an allergic reaction include peanuts, nuts, sesame, fish, shellfish, dairy products and eggs.
- Some people become wheezy when they eat food containing certain additives.
- The dye tartrazine (E102) is found in many foods and also in several medicines. People whose asthma is triggered by tartrazine may also react to aspirin.
- The preservative benzoic acid (E210) found in fruit products and soft drinks can also be a trigger.
- Some foods and wine contain histamine or similar chemicals called vasoactive amines that can trigger asthma.
Which foods can affect asthma?
- Sodium metabisulphite (E220-227) may also trigger asthma, but not via an allergic reaction. It can be found in wine, home-brewed beer, fizzy drinks, prepared meats and prepared salads.
- People with asthma are also recommended to avoid Royal Jelly products as they may trigger symptoms.
Remember, just avoiding your triggers alone is unlikely to control your asthma. You need to take regular asthma medicines as well.
Losing weight can help in managing asthma, and combined with a more active lifestyle, can also help to improve lung function.
Base your healthy eating plan around a variety of foods, including fresh fruit and vegetables, grains and cereals. It is recommended that you eat five portions of fruit or vegetables every day and drink plenty of water.
Foods that may protect against asthma
Some foods have also been found to help protect against asthma and improve lung function.
Dutch research has shown that people who ate the most fruit and vegetables had the healthiest lung function. Vitamin C and E are also believed to help reduce the severity of the inflammatory response in the lungs of people with asthma. A diet that includes a high level of nutrients can also boost the immune system and help ward off colds and flu - both common asthma triggers.
Fasting and asthma
You can read more about fasting and asthma here.
Weight loss and asthma
Losing weight can help in managing asthma, and combined with a more active lifestyle, can also help to improve lung function. Find out more here.
Salicylates can be found in a natural form (e.g. certain fruits, vegetables, herbs and plants) and in manufactured substances (e.g. solvents and perfume fixative). Salicylates are also found in certain medications that reduce inflammation and relieve pain, including aspirin and ibuprofen.
Salicylate sensitivity is a reaction that causes symptoms similar to those of an allergic reaction, but it is not a true allergy in the strict medical sense. If you think you may have salicylate sensitivity, it is important that you discuss your concerns with your doctor.
There is more information about salicylates and aspirin intolerance on the Allergy UK website. (Please note that we are not responsible for the content of any external sites, nor should selection be seen as an endorsement of them.)