Two common recommendations when someone has a cold or flu are, take vitamin C or echinacea. But what evidence do we have that they actually work? Well doctor Hasmukh Joshi, says, "Research has found no evidence that vitamin C prevents colds," and he should know because he is vice-chair of the Royal College of GPs.
A review of 30 trials took place in 2007. The trials involved 11,000 people and the authors came to the conclusion that, “regular ingestion of vitamin C has no effect on common cold incidence in the ordinary population”.
The authors did find that a daily dose of vitamin C meant that the time someone had the cold was slightly cut and the severity of colds was limited.
About 33% of the population believes that the flu virus can be cured by taking vitamin C. This is not true, vitamin C cannot cure the flu virus.
Doctor Joshi sums up by saying, "Studies found that vitamin C offers a very, very limited benefit. I wouldn't recommend it."
The next favourite treatment is Echinacea. This herbal remedy which has become mainstream is believed by many people to protect against colds. The seed, root and other parts of the plant are used in the remedies. Studies have been inconclusive in their findings.
A review of earlier trials dealing with echinacea found that people who took echinacea regularly had a 30% less chance of getting a cold. The studies lacked consistency because different preparations were used in different studies providing different results.
However no affect was seen on the length of time people had a cold whether taking Echinacea or not.
Doctor Joshi says that there is misplaced confidence that echinacea is an aid to the immune system when he tells us that in 2005 a series of studies proved that Echinacea had no affect on the immune system. But he admits, "I wouldn't recommend that it helps, but if people believe it, they can take it. There's no harm in it".
When talking about zinc, doctor Joshi is no more enthusiastic. Although he accepts that there may be some evidence to support the theory that taking zinc lozenges at the onset of a cold may minimise the number of days the symptoms are present. Some people believe that by lining the mucosa of the nose, in this case with zinc, then the virus cannot attach itself to the lining of the nose, with beneficial effects. However when tests were carried out the placebo group returned the same results as those taking zinc lozenges.
Getting cold or wet – Is it an Old Wives Tale?
The truth of the matter is that only a cold virus can cause a cold and only a flu virus can cause flu. However recent studies have indicated that being cold or wet may increase the likelihood of you suffering the symptoms of a cold or flu. This is because sometimes the virus can remain in your nose without displaying any symptoms.
A recent study at the Common Cold Centre in Cardiff carried out an experiment which showed that people who kept their feet in cold water for 20 minutes had double the chance of getting a cold as those who did not immerse their feet. It appears that many people can carry the cold virus without any symptoms developing.
The researchers believe that this is the reason that people with cold feet developed cold symptoms. They say that when you are chilled then the blood vessels in the nose constrict and this affects the nasal defences which allow the virus to develop.
Doctor Joshi reinforces the thinking that only a virus can cause a cold by saying, "Getting a cold from going out in the cold or after washing your hair is a myth. Colds are common. If the virus is already there and then you go out with wet hair and develop symptoms, it's common to think that is what caused it".
Does Anything Work?
If you want protection from the flu then you must be vaccinated. The flu vaccine is the only way to protect yourself from the flu. However by maintaining a healthy lifestyle you can minimize your risks too. Doctor Joshi sums up, "Eat a healthy diet, take regular exercise and drink plenty of warm drinks in the winter months. The important thing to remember is that most people are going to catch a cold in winter anyway, because there is no effective cure for cold viruses".