Milk is a common beverage in many Western diets. It contains many proteins and nutrients that improve the health of your bones, muscles and skin. Milk may also be enhanced with additional vitamins, such as vitamin D, and skimmed to remove some fat. However, some people react badly to milk, and congestion is a common symptom of this reaction. Milk generally does not earn its reputation as an agent of congestion, but there are certain cases in which it affects your respiratory health.
Common Knowledge and Folk Wisdom
People have spent centuries believing that drinking milk causes congestion, so you're not alone if you hold this belief. You may avoid giving milk to your children, especially if they have colds or other congestive symptoms, and you may feel your own conditions worsen after drinking it. In certain cases, drinking milk may cause or worsen your stuffy nose. However, research has generally disproved the belief that all milk causes congestion all of the time.
Scientific Findings on Cough and Congestion
Several studies have examined milk's effect on congestion. One study, published in the "American Review of Respiratory Disease," focused on whether or not milk had any effect on an existing cough. The study found that 5 percent of subjects experienced a looser, more phlegmy cough after drinking milk, but researchers ruled that such a small percentage was statistically insignificant. Notably, subjects who believed that milk causes congestion reported that they felt more congested after drinking milk, but their nasal secretions did not increase in accordance with their perceptions. These findings suggested that many reported increases in congestion due to milk or dairy consumption were due to the subjects' perceptions, rather than a measurable increase in mucus.
Sensitivity to Certain Proteins
While milk may not have a broad, consistent effect on congestion, some milk obtained from certain breeds of cow may be more likely to cause a reaction. The protein beta-CM-7, which is found in some milk, stimulates the mucus glands in your digestive tract. These mucus glands are identical to the mucus glands in your respiratory system, which may also be affected by the protein. Not everyone who drinks milk with the beta-CM-7 protein notices this effect, and the extent to which you become congested depends on your sensitivity to the protein. Existing respiratory conditions, such as a cold or asthma, may also trigger a reaction to this protein.
Cow's Milk Allergies
Cow's milk allergy affects from 2 percent to 7 1/2 percent of children. It is an immunologically mediated reaction to at least one of the two main proteins found in cow's milk, and its symptoms vary widely. Congestion and stuffiness are common symptoms of less severe reactions, as are eczema or hives. Highly sensitive children experience more intense allergic reactions, and may even be prone to anaphylaxis and death. A cow's milk reaction may be immediate, or it may take several days to manifest. Fortunately, you can avoid cow's milk by substituting goat's milk or cutting milk out of your child's diet, and the Mayo Clinic notes that most children outgrow a cow's milk allergy by the age of 3.
References
- "Archives of Pediatrics & Adolescent Medicine"; Do You Believe Milk Makes Mucus?; Allen Dozer and Maria Fareri; June 2004
- "The American Review of Respiratory Disease"; Relationship Between Milk Intake and Mucus Production in Adult Volunteers Challenged With Rhinovirus-2.; Pinnock, et al; February 1990
- "Sun Sentinel"; Myth Busting: Does Drinking Milk Lead to Congestion?; Anahad O'Connor; April 2010
- Auckland Allergy Clinic: Lactose Intolerance & Milk Allergy
- "MayoClinic.com"; Milk Allergy; August 2009
