Drinking milk increases mucus when kids have a cold

What the research found

A 1990 study gave 60 adult volunteers a cold virus and tracked their milk intake and symptoms for 10 days. Drinking more milk or dairy was not linked to more congestion or more nasal mucus, measured by weighing used tissues. People who believed milk makes mucus did report more cough and congestion, but they did not actually produce more mucus.

Australian allergy specialists say the thick, coated feeling after milk is not due to extra mucus. It is likely the texture of the drink, which also happens with other liquids of similar thickness. They also say coughing after cold milk is usually from breathing in cool air while drinking, and warmed milk usually doesn't trigger it.

A 2020 double-blind randomised trial tested a single serve of cow's milk against a soy milk substitute in children aged 6 to 18, with and without asthma. The researchers noted that milk is often cut out despite a lack of evidence. Healthdirect says doctors don't generally recommend avoiding foods such as milk to treat or prevent colds or coughs.

What it doesn’t mean

• The cold-virus study was in adults, not children, and was fairly small. The guidance supports the same conclusion for kids, but no large trial has tested milk and colds in young children.
• If your child feels more bunged up after milk, that feeling can be real. It doesn't mean more mucus is being made. Children with a diagnosed cow's milk allergy are a separate issue and should follow their doctor's or dietitian's advice.
• Keep fluids up when your child is sick. See a doctor if your child has trouble breathing, isn't improving after 48 hours, won't eat or drink, or has fewer wet nappies than usual. Ask a dietitian before removing milk long term, as dairy is an important source of calcium.