Myths and truths about flu and the common cold

The viruses that cause colds are spread through the air.
The viruses that cause colds are spread through the air. / SUR
  • Colds and flu can be prevented by taking certain precautionary measures, but there is a great deal of 'fake news' about avoiding and treating them which is unsupported by scientific evidence and can cause far more harm than good

Autumn arrives, and then comes the cold weather. It is a time of year when colds and flu are unwelcome but regular visitors. There are a great many myths about how to avoid them: contrary to common belief, keeping well wrapped-up and never going barefoot at home will be no use at all unless we take other, really effective, measures. In fact, catching a virus has nothing whatsoever to do with what we wear or whether we are outside in bad weather.

So if colds and flu are unrelated to the weather, why do so many people suffer from them at this time of year?

Well, there is a correlation, but not the one that many people think. Yes, it is a fact that most colds occur in the autumn and winter; that is due to a combination of factors, such as people spending more time together at home and in enclosed spaces such as offices and schools, and that increases the risk of exposure to viruses. In some climates the combination of cold weather and low humidity means nasal passages dry up, and that makes them more susceptible to cold viruses.

The question to which everyone wants an answer is, how can we prevent colds and flu? Experts recommend washing our hands carefully and regularly, not rubbing our eyes, covering our mouths with our forearm when we cough, using disposable handkerchiefs and not sharing food, glasses or cutlery. It sounds simple, but it is effective. Weighing ourselves down with heavy coats, scarves, hats and gloves, on the other hand, isn't.

Something else to bear in mind is that a cold is not the same as flu. They are two different illnesses even though they have similar symptoms. It is important to know how to tell the difference, because in certain people flu complications can be fatal, such as the elderly and patients with pulmonary and cardiac problems.

A high temperature, cough, muscular pain and headaches are usually associated with flu (and are rare with a cold), while sneezing, nasal secretion and sore throats are signs of a cold and do not, or very rarely, occur with flu. They are two completely different viruses.

It is essential to take note of that, because a whole network of urban myths has developed about the 'world' of colds and flu, even though they bear little or no relationship to the findings of scientific studies.

A classic example of a myth is the one about vitamin C, which for decades has been said to have properties which improve the immune system and help its defence against colds and flu.

Despite this or any other supposed anti-viral properties, no scientific tests have ever supported the theory. There is therefore no need for us to stuff ourselves with vitamin C if we come into contact with a virus, and if we don't wash our hands properly we will end up transferring it to our eyes anyway.

We will also catch the virus if we don't keep at a cautious distance from someone who already has it, because it is mainly transmitted through the air.

In fact, not even a strong immune system is a guarantee: a healthy adult can easily suffer from two to four colds a year, and children can have twice as many.

The case of the common cold is similar: it can be the result of over 200 different viruses which cause inflammation of the membranes which cover the nose and throat. Among all these, the principal ones are the rhinovirus, adenovirus and coronavirus. Our bodies are incapable of developing all the defences they would need to battle them all.

As well as the recommendations above for preventing flu, there is scientific evidence that the flu vaccine is a preventive measure which has proven its effectiveness in groups with the risk of greater complications. GPs will already have recommended a flu jab to patients who belong to one of the risk groups. The campaign has already begun in Andalucía and patients only have to go to their health centre to be given the vaccine. Remember that nowadays it is not only suitable for pregnant women, but is also recommended for them because they are part of a risk group and it is totally safe in this sub-group. It is also one of the safest vaccines, with the lowest side effects, and can never cause flu because it contains unactivated virus.

Children, elderly people and others in a risk group should have the flu jab every year. The risk groups include people over 65, those who live in residential or nursing homes, pregnant women and individuals with chronic medical problems.

Looking at another aspect of flu or the common cold, what should we do if we catch them? Let's start with what we shouldn't do. There are many 'alternative' remedies, including medicinal plants and other treatments, which are used to alleviate the symptoms. People believe that ginger and propolis can help them to feel better because of their analgesic properties, although there is no scientific evidence for this, and it is probable that any improvement which occurs in these people is the natural evolution of the illness.

Garlic and onion have also been used as remedies for flu processes, to prevent them as well as relieving their symptoms; some see them as two 'powerful antidotes' which are capable of battling different respiratory afflictions. However, once again, no clinical tests have supported these beliefs. Putting a raw onion in a room so you don't get flu is just one more myth. All it does is 'perfume' the room with the rather unpleasant odour of the vegetable.

If you don't want to catch flu, it is important to avoid contact with people who have it, and wash your hands regularly and thoroughly.

With regard to echinacea, some studies indicate that it may slightly relieve the symptoms of the common cold in adults, but has no proven effects on prevention or improving the body's defences.

It also interferes with other treatments which affect the liver: paracetamol, cortisone, immune suppressants, anti-tumoral drugs...

For that reason, these 'remedies' can even be harmful. Not only do they not cure the flu or cold, but could be contraindicated if someone suffers from another chronic health problem.

Treating flus and cold with antibiotics is also a big mistake. Flu is an illness which is frequently uncomplicated and self-limiting and its treatment is purely associated with symptom relief: staying hydrated, relative rest and the use of thermal analgesics like paracetamol or non-steroid anti-inflammatories should be sufficient.

Because flu is caused by a virus, antibiotics are no use because they only work against bacterial infections. Doctors will only prescribe anti-viral drugs for patients at risk.

Abusing antibiotics doesn't help people to get better faster, as many believe, and it can have an adverse effect. The indiscriminate use of antibiotics makes the bacteria more resistant to them (which means that if that person needs them in the future they won't work).

Because of all this, as always, it is preferable to be aware of such types of 'fake news', and stick to treatments which are supported by clinical tests.

If the high temperature persists and antipyretics have no effect, it is important to consult your GP to see whether you need a different treatment.

The OCU consumers association warns of another false belief about treatment of colds and flu: "We think we have to make sure we drink enough liquids, but the traditional advice of 'drink lots of liquid' when you have a cold or flu isn't proven scientifically. People should also bear in mind that the water our body needs doesn't only come from the liquids we drink but also the foods we eat," says the organisation, adding, "It is true that the sweating associated with a high temperature (a common symptom of flu) can contribute to dehydration to a certain degree, but that makes us feel thirsty, the best and most unmistakeable sign that our body needs us to drink water. It is sensible to be very careful with children and elderly people in this respect, however, because they don't always show the signs so clearly".

Stop smoking

Smoking is one of the worst lifestyle habits as far as health is concerned. As well as being the cause of serious illnesses such as different types of cancer and cardiovascular problems, it is also an enemy when combating less important illnesses like flu and colds, and not just because it produces a change in the immune system.

Studies show that smokers, especially the most inveterate ones, have a higher risk of getting flu or catching a cold, and their symptoms are more intense once they have done so. Breathing in environments contaminated by tobacco smoke damages the mucus of the respiratory passages, encouraging the adhesion and penetration of viruses and bacteria.

To sum up, the best thing is to take basic hygiene measures as a precaution in order to avoid catching or giving colds and flu to other people. The flu vaccine is a form of prevention and, although it doesn't guarantee 100 per cent immunity, it significantly reduces the risk of catching the illness at this time of year.

Finally, ignoring advice which is not supported by medical evidence will save you time and also money.