The common cold is the most common illness of mankind. On average adults suffer 2-5 colds a year and school children 7-10 colds a year. That is a minimum of 120 million colds a year. When you reach 75 years of age you will have suffered from more than 200 colds, and if each cold lasts 5-7 days, that works out as three years of your life spent coughing and sneezing. Colds are found in all animals such as cats, dogs, rabbits, cattle, sheep and even seals and whales have their own colds viruses. Colds are not only a nuisance they can be serious as they also cause chest infections in babies and the elderly, chronic ear problems, sinusitis and exacerbation of asthma.

The viruses that cause colds are extremely small. In a single layer, you could fit over 200 viruses for every person on earth on the face of a one pound coin!

Event the experts cannot tell the difference between a cold and flu just by the symptoms. Flu-like symptoms can be caused by common cold viruses. But real flu is caused by the influenza viruses. Influenza is with us every year and is more common in winter. The best way to protect persons at risk of complications from influenza is to get vaccinated every autumn. The influenza viruses are found in poultry and ducks and can infect humans to form a new strain of influenza. When a new influenza virus develops the whole world may be affected by a pandemic.

Colds and flu are mainly caught by coughs and sneezes that spread infected droplets of mucus in the air we breathe. Infected mucus can also be spread on to commonly touched surfaces. Colds are not very infectious and most colds are caught at home from partners and children, as you need long and close contact to catch a cold. Influenza is more infectious and spreads easily in public places.

There is only one sure way to avoid colds and flu and that is to become a hermit because if you are exposed to other people you are always at risk of infection. Hygiene measures such as hand- washing with soap and water can help prevent infection and if we all used tissues to trap coughs and sneezes this would also cut down the spread of colds and flu. Hand sanitizers are also useful to prevent infection from colds and flu.

Our crowded cities and public transport make it easy for colds and flu to spread and it is surprising we do not suffer from more infections. Our nose acts as a very good filter and traps viruses in a sticky layer of mucus. We swallow the mucus and cold and flu viruses are killed in the acid of the stomach. If the virus infects the nose then our immune system fights the infection.

Our immune system consists of billions of white cells- we make over one million white cells every second- that’s quite an army to fight infection. Our immune system can be kept in good shape if we have a balanced diet with plenty of fresh fruit and a little red meat. Meat is a useful source of zinc that is an important element for our white cells. So if you are a vegetarian you need to ensure you are getting enough zinc in your diet. Nuts, dairy foods, beans, lentils and yeast are a good sources of zinc, otherwise there are many zinc supplements to boost your intake.

Diet is not the only way of supporting our immune system. Mild exercise is beneficial and you need to get sufficient sleep as lack of sleep reduces our ability to fight infection. The immune system is also affected by stress so it is likely we will come down with a cold when we are stressed.

The common cold and flu viruses are around us all the time and most times we are able to avoid a cold or flu as our immune system overcomes the virus. When we neglect our diet, miss some sleep and are stressed our immune system is weakened and we come down with a cold or flu.

There is no substitute for a balanced diet and healthy life-style in avoiding colds and flu but there are some other natural ways that may help support your immune system. Probiotics, and the herbal medicines Echinacea and Ginseng are claimed to support the immune system and are worth a try.

If however you do come down with a cold or flu then do not pester your GP for antibiotics as they do not work against colds and flu viruses and cause more harm than good in these conditions. The pharmacy and supermarket have lots of symptomatic treatments. The pain killers aspirin, paracetamol and ibuprofen are good for controlling many symptoms such as fever, sore throat, muscle aches and pains, headache, sinus pain and that run down tired felling you get with colds and flu. A hot tasty drink made at home from honey and lemon or hot cordial is a good remedy for sore throat and is especially useful for cough in children as it can be taken at night as many times as needed. A blocked nose is a bothersome symptom and can make you feel really tired, as you cannot sleep with a blocked nose. Nasal decongestant sprays are the best remedy taken in the evening as they keep the nose open all night.

By Professor Ronald Eccles
Director

Common Cold Centre

Cardiff University