Mucus is a thick covering substance of the mucous membranes which line our internal hollow organs: stomach, intestines, nasal cavities, sinuses, trachea, bronchi, etc. Its main ingredient is a highly branched network of proteins with major structural component – mucin glycoprotein. The mucus contains also around 2% lipids and 90-95% salts, cells, electrolytes, different cell debris and water. The intestinal mucus acts as a stable barrier to control the passage of harmful molecules and microorganism, while supporting the implementation of efficient transport of nutrients across the epithelium. This controversial function is extremely important for effective drug and food transport. The mucus in the nasal cavities helps in providing moisture for the sensitive nasal mucosa. Nasal congestion or stuffy nose occurs when the mucus thickens and blocks the airflow in the respiratory system.
Protein products like eggs, milk, soya, fish, mussels, flour have a bad reputation because of their allergenicity and consuming them, especially if you are allergic, is possible to increase mucus production. But the opposite statement is not true – the avoidance of these foods, if you are not allergic to them, actually will not reduce the amount of the produced mucus from your body. Exactly this is the case with milk, despite the popular belief that the dairy products increase mucus production.
A research published in “Journal of the American College of Nutrition” in 2005 officially gathered data that drinking milk does not cause increased mucus production in the general population. In 2010 the Austro-Asiatic group of Clinical Immunology and Allergology also concluded, after series of studies, the statement that dairy products increase mucus production is groundless.
Some histamine containing foods like some fishes (anchovies, smoked fish, sardines), tomatoes, spinach, eggplants, avocados, mushrooms, dried fruits, processed meat and fermented products may increase mucus production within the allergic reaction. The symptoms of this reaction can vary widely but usually are stuffy nose, sneezing, coughing, throat discomfort, watery eyes, itching. The elimination of food allergens may help in such cases, and testing for food allergies will determine the specific food groups.
In conclusion, I can say that switching to a diet with no dairy products, without medical motives, may adversely affect human health. The withdrawal of the so called “mucus-producing foods” without the appropriate supplementation can lead to nutritional deficiency of vitamins and minerals such as vitamin D and calcium and may lead to the need of specialized medical care.