Posted on 13 Oct 2010 23:03
There is a long-held belief that consumption of milk causes the production of excess mucus and thus milk should not be consumed during a cold or by persons prone to sinus infections. It is furthermore held that avoiding milk will therefore alleviate the respiratory symptoms, especially those caused by colds. Ancient Ayurvedic tradition even holds that certain foods are mucus forming and that these include most animal products, grains, bean, and seeds.
In modern alternative medicine, however, milk seems to be the most widely reported mucus forming food. There is no clinical evidence, however, that this is true. Studies done to investigate this belief have found no statistically significant association between milk consumption and mucus formation. Subjects in the studies who believed that consuming milk cause them to have more respiratory symptoms were not found to produce higher levels of mucus or salivary secretions than those who did not believe this. It is possible that the perception of increased mucus production had more to do with the difficulty of swallowing the the perceived thickness of the mucus. This effect also seems to be duplicated by the consumption of a non-dairy soy-milk drink. The symptoms may have to do with a film left behind in the mouth from the milk itself, rather than the innate production of mucus, and milk and soy-milk have similar mouth-feel.
It is also believed by some people that milk consumption brings on asthma symptoms and many asthmatics report exacerbation of symptoms after drinking milk. Research concerning the relationship between dairy consumption and asthma, to date, also does not support this belief. The following report by Brunello Wüthrich, et al. examines the evidence:
Milk Consumption Does Not Lead to Mucus Production or Occurrence of Asthma
by Brunello Wüthrich, MD, Alexandra Schmid, Barbara Walther, PhD and Robert Sieber, PhD
Allergy Unit, Department of Dermatology, University Hospital (B.W.), Zurich
Agroscope Liebefeld-Posieux, Swiss Federal Research Station for Animal Production and Dairy Products (ALP) (A.S., B.W., R.S.), Berne, SWITZERLAND
There is a belief among some members of the public that the consumption of milk and dairy products increases the production of mucus in the respiratory system. Therefore, some who believe in this effect renounce drinking milk. According to Australian studies, subjects perceived some parameters of mucus production to change after consumption of milk and soy-based beverages, but these effects were not specific to cows’ milk because the soy-based milk drink with similar sensory characteristics produced the same changes. In individuals inoculated with the common cold virus, milk intake was not associated with increased nasal secretions, symptoms of cough, nose symptoms or congestion. Nevertheless, individuals who believe in the mucus and milk theory report more respiratory symptoms after drinking milk. In some types of alternative medicine, people with bronchial asthma, a chronic inflammatory disease of the lower respiratory tract, are advised not to eat so-called mucus-forming foods, especially all kinds of dairy products. According to different investigations the consumption of milk does not seem to exacerbate the symptoms of asthma and a relationship between milk consumption and the occurrence of asthma cannot be established. However, there are a few cases documented in which people with a cow’s milk allergy presented with asthma-like symptoms.
Key teaching points:
• In alternative medicine, a popular belief is that the consumption of milk and dairy products leads to mucus in upper and lower respiratory tracts.
• Sensations associated with increased mucus production are not specific to cow’s milk, but are more likely due to physical characteristics of some beverages.
• In rare cases asthma can occur in patients with confirmed food allergy against cow’s milk proteins.
• People with asthma are sometimes advised to abstain from the consumption of dairy products, but research shows that consumption of milk does not significantly change various lung function parameters. In addition, limiting dairy food consumption can lead to low intake of many nutrients, including calcium.
Wüthrich, Brunello, Alexandra Schmid, Barbara Walther, and Robert Sieber. "Milk Consumption Does Not Lead to Mucus Production or Occurrence of Asthma." Journal of the American College of Nutrition Vol. 24 No. 90006, 547S-555S (2005). Web. 13 Oct. 2010.