Wednesday 29th January 2020

Common Cold

Sneezing for a coldHow to prevent colds & treat colds. Myths & facts

No. Although common cold viruses can spread through the air and infect people in that way, a frequent way to catch a cold or flu is by shaking hands with a person suffering from a cold and then touching your eyes, mouth or nose.

This is one of the things to remember in order to avoid a cold.

No. Despite the many experiments performed, cold weather and humidity have never been proven to be the causes of common cold. In a study, volunteers who were soaked with water and exposed to cold draughts were not more likely to develop a cold than the volunteers who had remained dry and warm.

So the explanation for the fact that colds, although they can occur in any season, are most common from September to March, must be found somewhere else. A hypothesis is that in the colder months more people stay indoors in places with little circulation where viruses can spread more easily. Possibly our bodies are more vulnerable to infectious diseases in winter months because cold weather can make us physically low. So, in this sense, there is some truth in the idea that being cold can predispose us or make us vulnerable to developing common cold, but only in the presence of cold viruses. If you are at the North Pole but there are no rhinoviruses around, you will not, literally, "catch" cold.

This brings us to the subject of what we can do to protect ourselves and avoid getting a cold. Not everybody who is exposed to the different cold viruses (there are over 100 of them, that's why there is no vaccine) develops a cold.

We can strengthen our body's natural defences by eating a healthy and well-balanced diet; in particular, foods rich in vitamin C (citrus fruits - oranges, lemons, grapefruits, tangerines and so on - and red peppers) and zinc (whole grain foods, beans, nuts) are thought to help the immune sysytem, and scientific evidence partly supports this belief.

In my experience, I have found that drinking around a one-litre carton of pure orange juice (or another citrus fruit juice) every day has reduced the number of colds I get and, when I have a cold, it does not linger for more than a day, especially if I then drink more orange juice than my usual. This does not mean that it should work the same for everyone: it's just what they call 'anecdotal evidence' (you may also say 'one swallow does not make a summer') but I'm reporting this in case it's useful for somebody else.

Another of my favourite cold remedies is made by squeezing a couple of lemons and then adding hot water to the fresh juice. I drink it without sugar, although as you can imagine it's pretty sour. If you are like me, you'll get used to it and won't notice it so much. Otherwise, to make it more palatable you can always add sugar or, better, add extra water, which is also useful for your fluid intake (see below).

False. You don't need to eat more than is normal for you when you have a cold. Have a healthy and balanced diet. Drink a lot of non-alcoholic drinks, to replace water lost through sweating and so avoid dehydration. Preferred drinks are orange juice, any fruit juice and hot drinks, like vegetable soup.

No. Although it's a good idea to take things easy, and not going to work may be useful from the viewpoint of avoiding spreading the virus, you can carry on with your normal activities.

On the subject of contagion prevention, it's better to use disposable tissues rather than handkerchiefs.

False. Cold is a viral infection, caused by viruses, not a bacterial infection. Antibiotics are effective only against bacteria, not a virus, so they are useless to treat colds.

In fact, it should be actively discouraged to ask your doctor to prescribe antibiotics when they are unnecessary because their widespread use contributes to the creation of bacteria resistant to antibiotics, which is bad news for us all.

Illnesses generally have a so-called 'natural history': they tend to get better after a certain period of time, which in the case of the cold is from a few days to a couple of weeks. The art of medicine consists in amusing the patient while nature cures the disease is one of my favourite quotations by the philosopher Voltaire.

Sometimes a general practitioner may give in to a patient's request for antibiotics even knowing that they are ineffective to treat a cold, but it's not a good idea to make that request. The Proprietary Association of Great Britain, which represents the manufacturers of over-the-counter medicines, said in a general context, not just relating to colds: Doctors said that they would do anything to ensure patients left the surgery satisfied, including writing prescriptions for things that weren't needed.

If you take antibiotics (or any other ineffective treatment) when you have a cold, then when you eventually feel better (as you would have anyway), an association will be created in your mind between the two (antibiotics and relief from cold) which is purely imaginary and based on coincidence in time. The next time you have a cold you'll ask for antibiotics again, and this sort of unnecessary overuse increases antibiotic resistance in the community. This means a decreased efficacy of antibiotics when they are actually needed.

There is no cure for a cold. Or rather, the cure is nature itself, is in our body's healing capacities. After a certain time our immune system defeats the virus that caused the disease.

Hopkins, a surgeon commander in Britain's Royal Navy who conducted early clinical trials on cold remedies, famously said: "If a cold is treated energetically it will get well in 7 days, while if left to itself it will get well in a week".

There is controversy about whether the herbal remedy echinacea, vitamin C supplements, zinc supplements and garlic, which all have been alleged to boost the immune system in the fight against the common cold, are effective in preventing and treating colds.

Echinacea is a genus of nine species of wild plants native to North America, of which three are used as herbal remedies. The most frequently used species is Echinacea Purpurea, commonly called 'purple coneflower'. In in-vitro tests on white blood cells, the cells of the immune system defending our organism against pathogens (germs) and other foreign bodies, echinacea's extract has been shown to increase the number of white cells in the blood.

This in turn led to claims that echinacea boosts the immune system and therefore our defences against infection, but these claims have not been substantiated in properly controlled clinical trials. This is an over-extrapolation from lab tests conducted in test tube cultures to the complex systems of real human patients, in whom things can work in the opposite way to what happens on a laboratory bench. In addition, we don't know if long-term use of echinacea is safe.

I'd rather stick to orange juice, grapefruit juice and hot lemonades.


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Photo accompanying the article No273 13 Oct 2009 Sneeze by mcfarlandmo made available under an Attribution 2.0 Generic (CC BY 2.0).