Dairy products are good for the bones, so we’re encouraged to have regular serves of (reduced-fat) milk cheese and yogurt. But can they make asthma and allergies worse?
Asthma is a respiratory condition that causes the airways to the lungs to constrict when exposed to certain triggers, making it difficult to breathe. One in ten Australian adults and about one in nine children will suffer from asthma during their lifetime.
People with asthma generally aren’t put on a restrictive diet because it’s rare that food allergens trigger the illness. It’s more likely that food additives or food preservatives such as sulphur dioxide (identified on food labels by the number E220) will trigger asthma. This is relevant for 5% to 10% of asthmatics who may need to avoid the additive.
Around 2% of babies are allergic to cow’s milk. In this group, the ingestion of dairy products can cause asthma as well as other symptoms such as hives and vomiting. It’s important that parents obtain a correct diagnosis for children with the condition, using skin testing or blood tests to show the presence of allergy (IgE) antibodies to milk.
About 80% of children will grow out of their cow’s milk allergy. But while the allergy persists, it’s important to seek medical advice about alternative sources of nutrition and when to consider re-introducing milk.
In the other cow’s milk-related diseases such as FPIES, lactose intolerance and milk intolerance, the ingestion of milk will cause symptoms – usually gastrointestinal, such as diarrhoea and vomiting – but will not aggravate asthma.
Respiratory allergies such as asthma and rhinitis (hay fever) are usually triggered by what we inhale rather than what we eat.
Some people complain that the ingestion of milk causes a runny nose, makes their throat feel as though it is coated by thick mucus and triggers coughing. But research studies have shown that these sensations are due to the texture of the milk and can be similarly caused by fluids of the same thickness.
Studies have also shown that in people with asthma, the ingestion of milk has no effect on lung capacity and does not trigger asthma symptoms. Drinking cold milk may cause a cough in patients with asthma but this is more likely to be due to the temperature of the milk and can be avoided by warming the milk.
In children with asthma, a runny nose is more likely to be due to associated allergic rhinitis or a viral infection rather than milk in the diet.
Why we need calcium
Calcium is vitally important in the body for cell functioning. It’s stored in the bones and teeth where it supports their structure and function. Dairy products are the main source of calcium in our diet.
There are particular times in life – such as during growth spurts in children and adolescents – when new bone formation occurs and adequate dietary calcium is essential to facilitate this process. Maximum bone density is achieved during puberty and the higher it is at this time, the better one’s lifetime bone health will be. This is why adequate dietary calcium intake is especially important in childhood.
Further, many asthmatics are prescribed preventer medication which contains an anti-inflammatory corticosteroid medicine. At high doses, this is associated with the development of osteopenia and osteoporosis. So it’s important that asthmatics of all ages have an adequate calcium intake to meet their dietary needs:
- 210mg daily from birth to six months,
- 500mg in early childhood,
- 1300mg from ages 12 to 18 years,
- 1000 to 1200mg in adults.
These targets are difficult to achieve unless dairy products (milk, yoghurt, cheese) are part of the diet. If you’re not getting enough calcium, talk to your doctor or health professional about calcium supplements such as calcium carbonate or calcium citrate.