“Hello Rosie! Some thoughts on milk and milk-based foods and phlegm production would be much appreciated. Many years ago I had heard this, although our Respiratory Techs poo-pooed it. After some research I found they were right, although it seemed no one believed us. This issue has recently come to light again. I would appreciate any thoughts. No hurry. And once again, many thanks.”, asks Enlightened Eater Facebook fan Jennifer Burnham RD (Retired).
Jennifer, the supposed link between dairy products and mucus production is one that I, too, have been hearing about for many years. For those with dairy allergies, increased phlegm production could be how their allergy manifests itself.
As for the general population, the dairy-phlegm connection is one that scientists have continued to evaluate, most often looking at subjects infected with cold viruses. Almost all the studies, including those where subjects have collected nasal secretions, have found no connection.
There has been one exception, though, where scientists from New Zealand published findings in a journal called Medical Hypothesis. It appears that a compound beta-casomorphin-7 (beta-CM-7), derived from the milk of a certain kind of cows (A1) stimulates mucus production in the intestines. But if there is a particular type of inflammation in the lungs, such as in chronic lung disease there could be increased mucus or phlegm production in these individuals.
But so far, this is only a theory.
It might seem like a smart idea, in light of this study, to forego dairy products at various times, such as when you have a cold. But before you do this, there are other considerations.
For one, beta-CM-7 (the compound from A1 cows) may offer health perks. It seems this increase in mucus production in your gut may supply protective effects by lining the intestines. Scientists are also researching possible benefits for those with type 1 diabetes in defending against kidney disease.
Other preliminary research suggests some possible negative effects of beta-CM-7 from A1 cows. A2 cows appear to yield a different milk. At this time, though, when you buy milk, we simply don’t know what kind of cow it came from.
Stayed tuned for more research on the topic.
Do you avoid dairy products when you have a cold? Please share your thoughts in the comment section.
Enlightened Eater 
I suffered with chronic sinusitis most of my life. At one point I needed surgery to remove scar and inflamed tissue. I went dairy free 20 years ago and it has been life changing (I am 64). No more sinus infections or antibiotics.
That’s great to hear Patty! Finding a solution for a chronic problem is definitely life changing! As the research shows, there is a small segment of the population that may benefit from going dairy-free. It’s great that you’re one of these people. It’s also important to keep in mind that research points to trends and relationships but it’s always important to note that there are exceptions to what scientists find!