Mucus is naturally found in the body and is a film that covers the surfaces of the respiratory and digestive systems, providing protection against damage, infection and irritation.
It is produced by specialised cells and consists of water and various different proteins.
There is a belief among some groups, that consumption of milk and dairy products increases the production of mucus in the respiratory system and that these foods should therefore be removed from the diet.
The original myth stems from the 12th century when a physician attributed a “humidifying effect” (or mucus thickening effect) in humans to consumption of dairy products, with the exception of butter.
Traditional Chinese medicine also suggests milk and dairy foods are mucus-forming along with other products such as chocolate, honey and all other natural sweeteners.
It is therefore not surprising that people suffering with upper respiratory tract disorders associated with increased mucus production, and following alternative medical practices, are advised to exclude milk and dairy from the diet.
This is concerning since this myth has no scientific basis, and may lead to unnecessary exclusion of a food group which can provide such a vast array of nutrients essential to good health.