Causes of the common cold and other old wives’ tales: the Vitamin C angle

My nose is still stuffy as I write this, I’ve been nursing a cold for days and I figured I’d read about the common cold and find out why it is often associated with Vitamin C deficiency. The reading started by revisiting something I wrote five years ago about some fantastic theories on what causes the common cold and the comments from readers were replete with all kinds of weird superstitions. Read it, and the comments, and be entertained.

But even before going into the Vitamin C deficiency angle, let me start by saying that the common cold is caused by a virus (it is a different virus if the cold is a precursor to influenza) which infects the upper respiratory tract. A virus. Despite being called the COLD, it is not caused by exposure to cold weather or by ingesting large amounts of something cold especially during cold weather — like eating too much ice cream when it’s raining cats and dogs. We’re smack in the middle of summer here in the tropics and I have a bad cold.

Moreover, the viruses that cause the common cold are not airborne. In short, when someone infected with a cold sneezes or coughs without covering his mouth, the persons around him will not catch the virus that way. It is spread via physical contact.

The primary means of spreading a cold is through hand-to-hand contact or from objects that have been touched by someone with a cold.

The typical transmission occurs when a cold sufferer rubs his or her nose and then, shortly thereafter, shakes hands with someone who, in turn, touches his or her own nose or eyes.

Alternatively, virus transmission often occurs via doorknobs and other hard surfaces, such as subway handrails, grocery carts, office telephones, and computer keyboards. [Source]

Now, the Vitamin C angle. Why is it that when one has a cold, one of the most common remedies is large dosages of fruit juice — especially citric juices? The most common answer is to supply the body with large amounts of Vitamin C to cure the cold. Is there a factual basis for that?

There are at least two studies that show that Vitamin C does not cure nor prevent the common cold. See Vitamin C for preventing and treating the common cold and Examining the evidence for the use of vitamin C in the prophylaxis and treatment of the common cold.

The juice therapy may be rooted in something really sensible — the need for fluids to break up the congestion. But fluids do not have to be in the form of fruit juices. Water, herbal infusions and brews, and soups are great too. Which is just as well because the truth is, I hate drinking citric juices when I have a cold because the acid makes my throat even more itchy and, when the cold is accompanied by a cough, and that is often the case with me, downing too much juice makes my cough even worse.

The even bigger truth is that there is no cure for the common cold. There are reliefs, certainly, like inhaling steam to relieve nasal congestion or saltwater gargles to relieve an itchy throat. Still most reliefs work in the form of a placebo.

So, does that mean we should just ignore Vitamin C in our daily diet? Well, no, of course not. We need it to stay healthy. Which now brings me to another common belief that the best sources of Vitamin C, or ascorbic acid, are acidic fruits. In fact, I know a lot of people who think that the more sour the fruit, the better source of Vitamin C it is. Ergo, a lemon has more Vitamin C than an orange, and so on, and so forth.

NOT TRUE. Some foods that don’t even have the slightest taste of acidity are even better sources of Vitamin C than sour fruits. sources of Vitamin C

The table is from Wikipedia; countercheck the data with other sources if you feel that Wikipedia is not all that reliable. I did and I found pretty much the same things — peppers, broccoli and parsley contain more vitamin C than lemon and orange. See this and this, for instance. There are more but I’ll leave it to you to find them.

With all that in mind, I’ll stick to the Golden Rule for treating the common cold — sleep, rest, and more sleep and rest.