Does Milk Make Mucus?

I have heard many reports that milk worsens nasal congestion. Do you ever advise patients to avoid milk or milk products for this reason?

Although the belief that milk worsens nasal congestion, postnasal drip, respiratory congestion, or asthma is common, there is strong evidence against this belief. Researchers found no effect of milk on nasal secretions or on the symptoms of upper or lower respiratory tract mucus production. Nor did milk cause an increase in nasal congestion or secretions in volunteers who were infected with a common cold virus.

Why is the belief that milk causes respiratory problems so common?

Researchers found that those who believed that milk caused symptoms were more likely to feel a coating over the mouth, throat, or tongue, and a need to swallow often. These subjective sensations occurred also with a placebo nondairy drink. Thus, the texture of milk may have the effect of increasing awareness of mucus in the mouth and nasal passages.

Observant mothers have noticed a relationship between milk ingestion and the development of nasal, throat, or respiratory congestion in infants who are allergic to milk. However, many controlled studies have shown that food challenges rarely cause isolated respiratory symptoms in infants. Rather, allergic skin (hives or eczema over whole body) and gastrointestinal manifestations (vomiting, diarrhea) are more apparent.

Children allergic to milk will have symptoms of allergy as long as they continue to drink milk. I

n the majority of children who continue to drink milk, nasal congestion caused by the common virus, will clear up within 2 weeks.

Many children with colds will throw up mucus after drinking milk. This does not mean they are allergic to milk. During a cold, your child is normally swallowing mucus that is draining out of the sinuses. This mucus collects in the stomach. Milk will sometimes churn up this mucus and cause your child to vomit. This is one of the normal ways for your child’s body to get rid of this mucus.

In conclusion, I do not advise milk avoidance when a child has a cold and would not test for milk allergy in the absence of other signs of allergy.