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Milk, Mucus and Cough

pdfASCIA PCC Milk mucus cough 2019115.22 KB

Some people believe that when they drink milk their throat feels coated, and mucus is thicker and harder to swallow. Research has shown that these feelings are not due to increased production of mucus. These feelings can be due to the texture of the fluid, as they occur with similar liquids of the same thickness. Symptoms of cow's milk allergy are very different.


Mucus is produced by cells within the nose, sinuses and lungs.  It consists of water, salt and various proteins that help trap germs and particles of dirt. Antibacterial enzymes and proteins in mucus, called antibodies, recognise germs so they can be removed by the rest of the immune system, and protect from infection.

Too much mucus is usually caused by infections or allergy, and can make the nose run or drip down the back of the throat, leading to post-nasal drip. It can trigger cough, sore throat and a husky voice.

Thick, dry mucus can irritate the throat, is hard to clear and is more common in older people, and dry inland climates. Air conditioning, winter heating, dehydration and some medications can aggravate the condition.

Milk does not cause middle ear infections

Middle ear infections are common in early childhood, and especiallyin children who have allergic rhinitis (hay fever). Allergic inflammation causes swelling in the nose and around the opening of the ear canal, interfering with drainage of the middle ear. 

Children with cow's milk allergy may appear to have more frequent infections. This is not because milk causes infection, but rather because children with food allergy are more likely to have allergic rhinitis and other allergies.

Dairy product rarely trigger asthma or allergic rhinitis

Asthma and allergic rhinitis are normally triggered by inhaled substances, such as pollen, dust mite, mould spores or animal dander. Dairy products rarely trigger asthma or allergic rhinitis. When they do, nasal symptoms usually occure with symptoms of allergy, such as severe hives (urticaria), throat or tongue swelling, or a drop in blood pressure.

Studies have shown that milk has no effect on lung capacity, and does not trigger symptoms in patients with asthma. When people report coughing after having cold milk, it is usually due to breathing in cool air as they drink. This symptom generally disappears if the milk is warmed.

Cutting out important foods can affect nutrition

Dairy products are an important source of calcium and other minerals needed for strong teeth and growing bones. Cutting out cow's milk can limit choices, and may negatively affect nutrition. Diet restrictions do not  benefit most people with asthma or allergic rhinitis, and can distract efforts away from allergen avoidance. If cow’s milk avoidance is needed, see a dietitian for advice.

© ASCIA 2019

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Updated May 2019