Some myths about mucus
There is a commonly held view that people with asthma should avoid milk and other dairy products, because they are said to promote the production of mucus, and hence trigger asthma attacks. This perception dates back more than 2000 years, when some alternative medicine systems attributed excess mucus production to the consumption of milk.
According to the National Asthma Council and the Australasian Society of Clinical Immunology and Allergy (the peak professional body of allergy and immunology specialists in Australia and New Zealand), it is rare for dairy foods to trigger an asthma attack.
Genuine allergies to cow’s milk are caused by a milk protein, and may cause a variety of symptoms, including hives, eczema, vomiting, diarrhoea and wheezing.
How do milk and dairy products affect my asthma?
When milk is consumed it temporarily thickens saliva in the mouth, a sensation that many people mistake for respiratory mucus production. This sensation is not due to increased production of mucus — it results from the creamy texture of the fluid itself and will also occur with other liquids of similar ‘thickness’. There is no clinical evidence to suggest that reducing or stopping consumption of milk and dairy products will help relieve symptoms of asthma. Asthma symptoms are usually caused by substances that are inhaled (such as dust mite allergens), not those that are eaten.
Some people may cough after drinking cold milk, but this is usually due to breathing in cool air while they drink. Warming the milk first can help.
Asthma and your diet
Adverse reactions to any foods, including dairy products, are relatively rare in people with asthma — less than 5 per cent of people with asthma are affected by foods, drinks or food chemicals.
Getting enough calcium
Dairy foods are a major source of calcium, as well as vitamins A and B12, riboflavin and protein. More than half of the recommended daily requirement for calcium in the Australian adult diet is provided by milk and dairy products.
The National Asthma Council reports that many people with asthma are unnecessarily depriving themselves of a rich and important source of nutrients by limiting dairy foods. Dairy foods, which are crucial for bone development and growth and for overall good health, are recommended as part of a healthy balanced diet for most people with asthma.
The National Health and Medical Research Council (NHMRC) has issued the following recommended dietary intakes of calcium for Australians.
| Recommended dietary intakes of calcium for Australians | |
|---|---|
| Group | Calcium RDI (Recommended Dietary Intake) |
| Children one to 3 years | 500 mg per day |
| Children 4 to 8 years | 700 mg per day |
| Children 9 to 11 years | 1000 mg per day |
| Children and young people 12 to 18 years | 1300 mg per day |
| Men 19 to 70 years | 1000 mg per day |
| Men aged 70+ | 1300 mg per day |
| Women 14 to 18 years who are pregnant or breast feeding | 1300 mg per day |
| Women 19 to 50 years, including women who are pregnant or breast feeding | 1000 mg per day |
| Women aged 51+ | 1300 mg per day |
| Source: Australian Government Department of Health and Ageing and NHMRC. Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes, 2006. Endorsed 9 September 2005. | |
If you choose to avoid dairy products because of concerns about your asthma, it is important to identify appropriate substitutes to ensure you don’t compromise your or your child’s intake of nutrients.
While milk and other dairy products are the richest source of calcium, it is also found in:
- green vegetables such as bok choy and broccoli;
- canned salmon with bones and canned sardines;
- calcium enriched soy drinks;
- tofu processed using calcium; and
- almonds and calcium-fortified breakfast cereals.
Major medical organisations advise that the best way to get all the nutrients you need, including calcium, is through eating a balanced diet. However, in some situations, a calcium supplement may be indicated.
Talk to your doctor
If you have asthma and you are concerned about the effect of milk and dairy products on your condition, talk to your doctor or health professional.
Unless you have been tested and diagnosed by a specialist doctor as having an allergy to dairy foods that is triggering your asthma, there is no need to cut them out of your diet.
