Dairy products and Asthma

In this Article (Index)

• The Milk Myth
• Cow's Milk Allergy
• Food Allergies and Asthma
• Asthmatic response and milk
• Symptoms of Milk Allergy
• Tips for avoiding asthma-like responses

The Milk Myth

There is a popular belief that milk and other dairy products cause asthma or worsen asthma symptoms. This is not true in most of the cases. The National Asthma Council Australia points out that "Milk, cheese and yoghurt can all be enjoyed as part of a balanced diet unless you have proven allergy to cow's milk." (7)

There is plenty of evidence showing that consuming milk does not seem to worsen the symptoms of asthma. "However, there are a few cases documented in which people with a cow’s milk allergy presented with asthma-like symptoms."

Cow's Milk Allergy

Cow's milk allergy (CMA) is an immune reaction to proteins found in cow's milk. It affects roughly 0.6 to 1.6% of the population. It shouldn't be confused with Lactose intolerance, which isn't an allergy (it is caused be the lack of an enzyme, lactase, that makes them unable to break down the sugar found in milk -lactose).

There is evidence that people with CMA undergo an increase in sensitization over time, as shown by the higher than expected rates of CMA in US adults. (1)

Food Allergies and Asthma

There is strong evidence from observational studies that show a link between food allergies and asthma.

Asthmatic children are more sensitized towards food than non-asthmatic ones. Certain allergenic foods like milk, soy, peanut, wheat, egg and fish trigger specific IgE antibodies in 45% of the cases.(4)

These allergens may trigger symptoms similar to asthma.

Symptoms of Milk Allergy

Cow's milk allergy can be either immunoglobulin E (IgE) or non-IgE mediated.
The IgE-mediated reactions take place immediately after drinking milk, and the non-IgE mediated take much longer to develop (up to 48 hours). Both involve the immune system.

Only one of these reactions, the IgE mediated reaction, provokes respiratory symptoms.

The upper respiratory tract symptoms include itching iin the nose, sneezing, runny nose and congestion, with or without watery eyes.

The lower respiratory tract symptoms are similar to those of asthma: cough, chest tightness, wheezing, and shortness of breath.
They can also be combined with gastrointestinal and skin reactions like rash and itching. (6)

Asthmatic Response and Milk

Studies have shown that milk triggers asthma-like symptoms. It "Cow's milk can cause wheezing in children with asthma." (2)

It also affects adults, as shown by Zdenek (3), who reported that cow's milk allergy "cow's milk allergy can participate in pathophysiological mechanisms underlying bronchial asthma in some... adults with bronchial asthma... result[ing] in the appearance of various Asthmatic Response types (immediate, late, dual late or delayed)."

Using data from 7,432 children aged 9-11 years, from the French Six Cities Study, researchers found that "butter intake was associated positively with past year wheeze... and lifetime asthma" increasing their risk by 24% in each case. (5)

Tips for avoiding asthma-like responses

Avoid Omega-6 fatty acids

Omega-6 fatty acids are part of the polyunsaturated fatty acids or PUFA group. They are found in beef, dairy products, and vegetable oils as well as products obtained from them, such as margarine.

Omega-6 fatty acids may increase the risk for asthma; there is clinical evidence that shows that consuming a large amount of saturated fat "increases the expression of genes involved in airway inflammation in people with asthma, and diets enriched with omega-6 fatty acids hinder the incorporation of omega-3 fatty acids into plasma and tissue lipids." (8)

It seems that one of the omega-6 fatty acids (arachidonic acid) is a precursor of leukotrienes, which are chemicals that your body releases in the presence of allergens, which have an impact on the respiratory tract.

Omega-3, on the other hand, have benefic effects, they are anti-inflammatory agents.
Consuming a high proportion of "omega-6 to omega-3 fatty acid intake has been significantly associated with the risk for asthma" among infants. (8)

Avoid dairy products

Although "Excessive milk consumption has a long association with increased respiratory tract mucus production and asthma" this association does not imply a cause-effect relationship and it only affects a small group of people who react by producing more mucus in their respiratory tract. It is this subgrup that notices that "many of their symptoms, including asthma, improve on a dairy elimination diet." (9)

Closing Comments

Only certain asthmatic people, those who are also allergic to cow's milk can experience asthma-like symptoms when ingesting milk. This reaction shouldn't be mistaken for lactose intolerance, which isn't an immune system reaction and is different to cow's milk allergy.

Milk is a natural food with many nutrients and health benefits, it also contributes towards your daily requirements of Iodine.