Coughing & Cold Water: the Asian myth exposed

Hello everyone. I am in the process of exploring a few medical myths that I grew up with, in the last post in this series, I discussed whether or not it was dangerous to exercise when you were recovering from a cold or the flu. In today's discussion, I am going to look at the myth that you cannot have any cold food or drink (so anything from a glass of cold water to ice cream is forbidden) when you have a cough as it would supposedly make your cough worse. Now that was a myth I had grown up with in Singapore, but upon verifying with my friends, it seems that it is generally a widely accepted belief in South-East Asia. If this is true, then surely it must affect all humans regardless of our nationality?

Does cold water make your cough worse?

Now when I present this theory to my European friends, they usually look at me in disbelief or confusion - like how can cold water make your cough any worse? It is just water, what harm can it do? So the easiest way to test the theory is to drink cold water and eat ice cream when I have a bad cough and the conclusion is that it doesn't make my cough any worse or better - in fact, it made no difference whatsoever. It is uncanny to see that this myth only exists in South-East Asian countries, but somehow, nobody in say Australia, America or Europe is affected by it - hence this cultural dimension to the myth is curious to say the least. After all, we're all humans and we all suffer from the same cough - so why is it only South-East Asian people seem to be affected by cold water when they are coughing?

Let's look at the science behind the myth - it is never pleasant when you have a nasty cough (trust me, I am coughing right now as I am typing this.) We rarely cough when we are healthy and thus having this constant cough, bringing up a lot of phlegm and having a runny nose to go with it is frightfully unpleasant to say the least. It is often associated with a respiratory tract infection that we can get when suffering from a cold or the flu or it may be a symptom for another condition. Is there any reason why cold water should make your cough any worse? Not really - well, a lot of this myth is based on a misinterpretation and misunderstanding of the concept of Yin and Yang in Chinese medicine. Now for those of you unfamiliar with this concept, the Chinese believe that one's health is dependent on establishing a balance between the Yin ('cooling') and Yang ('heating') forces in our body. When you are ill, it indicates that your Yin and Yang are unbalanced thus you should try to help bring this back into balance by making wise choices with your diet.

Can you identify Yin and Yang foods in the picture?

Now some of these make sense, others don't. For example, if you have a sore throat then according to Chinese medicine, you have too much Yang forces in your body, so you can counteract that by eating something like watermelon which has plenty of Yin forces to help redress that balance. Now even if you don't believe in Chinese medicine, this actually makes sense as a slice of watermelon will have plenty of fluids that your body needs, the vitamin C in the fruit will help aid your recovery and the fiber will aid digestive transit. However, should cold water be considered Yin? Water in itself is considered neutral - chilling the water or even freezing it doesn't make it more Yin as altering the temperature of the water doesn't change the chemical characteristics of water: rather, this misunderstanding and misconception is a result of Chinese people taking the term 'cooling' a little bit too literally.

Hence we have a situation where Chinese people are trying to apply the principle of Yin and Yang without actually understanding it clearly and the adoption of the English word 'cooling' to represent Yin forces has been taken rather too literally by many - hence the aversion towards chilled water as a beverage deemed too Yin for those with a cough. There are other cultural factors we have to consider as well: let's go back to my late grandmother's generation - she was born in Singapore around 1920. She wasn't educated and lived through WW2, she didn't have any concept of Western medicine and she relied mostly Chinese medicine when she was unwell. In Chinese medicine, there is a tradition of going to the herbal medicine specialist who will prescribe a blend of medicinal herbs (and animal parts) which will help make you feel better - you take the blend of herbs, put it in a pot and boil it for a few hours to create a medicinal brew, which you then drink as medicine. Hence there has always been this cultural association of medicine with hot brews, my grandmother used to be very suspicious of swallowing pills prescribed by her doctor because she just wasn't convinced that proper medicine should take that form. We used to ground the pills down into powder and serve it to her in a cup of hot chrysanthemum tea, so it was more familiar to the kind of medicine she was used to.

My late grandmother was very Chinese.

We take it for granted that we all have fridges these days in every kitchen and having ice cubs and ice creams in our kitchens is no big deal - but to my grandmother who only got her first fridge back around 1960 and even though she had been served chilled drinks and cold deserts before, she wasn't used to the sensation of drinking cold water. It was a novelty she never really got used to, hence I remember her storing packet drinks and can drinks in the fridge but taking them out of the fridge to warm them up to room temperature before consuming them. Thus there was always something about people from her generation who were suspicious about not just cold water, but any kind of food that was served cold - for them, you knew the water was safe to drink if it was boiling hot. like a cup of tea. That meant the water had been boiled and any germs in the water had been killed. Thus her generation never craved cold drinks - that was why she used to view it at best with suspicion, believing that it could cause a cough. None of her beliefs had any scientific basis - it was merely based on the fact that she was unaccustomed to drinking cold water.

When such myths get passed from one generation to the next, you have the problem of confirmation bias. Let's imagine you have a young Singaporean student who was brought up believing that drinking cold water would make her bad cough even worse - when she drinks hot water and then coughs anyway, she would simply brush it off and think, "oh my cough is so bad that I would cough no matter what I do, hot water wouldn't make my cough any worse." But if she drinks some cold water and feels the urge to cough, that's when we have the problem of confirmation bias: she would be conditioned to match the experience to what she had been told many times by her friends and family. The fact is when you have a bad cough, whether you drank hot or cold water or nothing, you would still cough anyway - such is the nature of having a very ticklish cough. When you're under so much duress from having a bad cough, you're far less likely to be completely rational when it comes to doing anything that can alleviate your discomfort.

What makes you sneeze or cough?

There is another myth that any kind of citrus fruits could aggravate your cough: how much truth is there to that myth?  The information I found on the internet produced conflicting information: some websites said nothing about citrus fruits, others claimed that it could make you cough more whilst some prescribed orange juice and lemon juice as a remedy for a cough! My conclusion is that eating an orange or drinking some orange juice isn't going to make you cough any more - it is not irritating enough to your respiratory system to trigger off an adverse reaction. It contains plenty of vitamin C which your body will need to aid the recovery process. If you want to talk about foods that will provoke a coughing reaction, then you only need to watch this famous viral video about the cinnamon challenge. Yeah cinnamon will do that to you, not oranges. Now, feel free to laugh at the silly video but please don't try this at home!

So, in short, there is completely no basis for avoiding cold water and foods when you have a cough - the fact that this myth doesn't really exist outside South East Asia ought to tell you that it really doesn't have any scientific basis. If you have a really bad cough, then see a doctor and get some medication to deal with it. If you have any other medical myths you would like me to explore on my blog, why not drop me a line before through the comments section and we'll talk about it. Surely not all the Asian myths I was brought up with are totally rubbish? Many thanks for reading!