Dr. Prajeesh Balachandran Chirackal

 MBBS, DCH, DFM (RCGP), PGPN
 

Myth is a widely held but false belief. If repeated often, people who know the truth may start to doubt themselves. Myths, when believed in, tend to become true in the long run.

It is a common belief prevalent among parents that milk should be avoided with any respiratory illness or even a common cold. We, pediatricians, have been repeatedly told by the parents that drinking milk increases mucus production and so, they stop their child from having milk.

This is particularly so in patients with conditions associated with excess mucus production, for example, cystic fibrosis and primary ciliary dyskinesia, but also include children with infant wheeze or asthma.

Milk is the principal source of calcium for children and adults, as well as a good source of several vitamins. Adequate intake of calcium is crucial for the development of normal bone health and the prevention of future osteoporosis. Furthermore, in those avoiding milk, childhood fractures are more common than in the general population. This issue is, in particular, important for children with respiratory diseases which may require frequent courses of oral corticosteroids, as these drugs tend to decrease the absorption of calcium from the intestine.

Several studies have been conducted worldwide to obtain real evidence to correlate milk/dairy intake and symptoms of upper/lower respiratory tract congestion/infection/increased nasal secretions production. However, none of these studies have proved any correlation between the two.

Milk is an emulsion (suspension of droplets of one liquid in another) of fat in water, and it is a known fact that emulsions mix with saliva. Saliva contains high molecular weight mucin (MUC5B) and mucins are responsible for the viscoelastic properties of saliva. They also quickly induce the extensive formation of aggregates increasing the viscosity and volume.

This may explain why so many people think there is more mucus production after milk intake, when in fact, it is these aggregates of milk emulsion lingering in the mouth and throat causing the sensation.

Conclusion

While certainly, the texture of milk can make some people feel that their mucus and saliva are thicker and harder to swallow, there is no evidence (except to the contrary) that milk leads to excessive mucus secretion. Milk is an important source of calories, calcium, and vitamins for children and hence must have a place in their daily diet.

“The Milk–Mucus- Myth needs to be rebutted firmly by the healthcare workers”

References 

Wüthrich B, Schmid A, Walther B, et al. Milk consumption does not lead to mucus production or occurrence of asthma. J Am Coll Nutr 2005;24:547S–55.

Rosner F. Moses Maimonides’ Treatise on Asthma. J Asthma 1984;21:119–29.

Dharmananda S. Giving out bad advice? Why natural health care practitioners need to be careful about recommending restricting dairy products. Institute of traditional medicine. www. item online. org/ arts/ dairy. htm (accessed 18 Jun 2018).

Bus AE, Worsley A. Consumers’ health perceptions of three types of milk: a survey in Australia. Appetite 2003;40:93–100.

Dawson KP, Ford RP, Mogridge N. Childhood asthma: what do parents add or avoid in their children’s diets? N Z Med J 1990;103:239–40.

Black RE, Williams SM, Jones IE, et al. Children who avoid drinking cow milk have low dietary calcium intake and poor bone health. Am J Clin Nutr 2002;76:675–80.

Goulding A, Rockell JE, Black RE, et al. Children who avoid drinking cow’s milk are at increased risk for prepubertal bone fractures. J Am Diet Assoc 2004;104:250–3.

Bartley J, McGlashan SR. Does milk increase mucus production? Med Hypotheses2010;74:732–4.

Arney WK, Pinnock CB. The milk mucus belief: sensations associated with the belief and characteristics of believers. Appetite 1993;20:53–60.