Medical myths: Milk makes you phelgmy when you have a cold
Where did the myth come from?
As with so many of these myths, this is something my mum swears by. The worst part of having a cold as a child was that we were banned from having chocolate biscuits—my mum said the chocolate would make the phlegm worse. I suspect it was a ploy to keep the biscuits to herself.
The myth likely dates back to the 12th century, when the physician Moses Maimonides recommended removing dairy products to improve congestion. The idea is also in ancient Chinese medicine.
While not based on fact, it's probably because dairy products are of a thicker consistency and so people assumed it must make the body's fluids thicker too.
What's the truth?
Various studies have been done, such as infecting volunteers with the cold virus and giving some dairy products and others none. There was no difference between the two groups.
In fact, all studies have concluded that milk has no effect on your phlegm. Further studies have shown there's no difference in those who drank milk and those who drank water.
So, there's nothing to worry about?
Milk will make no difference to your phlegm when you have a cold, so feel free to eat as many chocolate biscuits as you like—they may not be actually good for you, but they certainly won't make your cold any worse. And when you've got a cold, you need a treat.
Mum, I hope you're taking note.