Vitamins and supplements for cold & flu relief
With the misery of the cold and flu season, many people turn to natural cold and flu remedies, such as vitamin C, zinc, echinacea and others.
But do alternative treatments offer the relief that pharmaceutical companies can't? There's growing evidence to suggest that some might - at least to a modest degree.
Natural cold and flu remedies: How good is the evidence?
First things first: cold and flu viruses are not the same thing. While colds are unpleasant, flu is much worse.
- The symptoms of flu are more severe; they include fever and body aches along with congestion.
- Flu can be dangerous, especially for older people. Public Health England says estimates of the annual number of deaths attributable to flu average are around 8,000 per year.
Which natural cold and flu remedies should you consider?
The following offers a guide to the cold and flu supplements most often recommended by the experts. Note that some have been studied with colds and others with flu.
Vitamin C for colds
While vitamin C has long been used for treating and preventing the common cold, evidence for this has been lacking.
A 2013 review of all the good quality evidence for vitamin C and colds found that taking vitamin C supplements doesn't stop people getting colds, or cure them once they have a cold.
In some cases, researchers found that vitamin C might slightly shorten the number of days with cold symptoms.
Bear in mind that the high doses of vitamin C sometimes recommended for colds and flu can upset the stomach and even cause diarrhoea in some people. Also, it is not a good idea to give high doses of vitamin C to children.
Echinacea for colds
Echinacea has been granted a Traditional Herbal Registration Certificate in the UK by the Medicines and Healthcare products Regulatory Agency (MHRA). This allows it to be sold for the relief of symptoms of the common cold and influenza (flu) type infections, based on traditional use only. Registration is not based on data from clinical trials. In fact, studies of echinacea for the common cold have had mixed results. While some studies do not support echinacea as a treatment, others show it can reduce the length and severity of colds by 10% to 30%.
It is possible that some of the conflicting study results could stem from researchers testing different species of echinacea. So far, the best evidence supports taking Echinacea purpurea, which is also the most widely available.
Can echinacea also help prevent you from catching cold or flu viruses? Most studies do not support this.
Echinacea does have some mild risks. If you have allergies to ragweed or certain flowers, don't take echinacea before seeking medical advice. Also, it may not be safe for people with certain diseases that affect immunity, such as autoimmune conditions like rheumatoid arthritis and lupus.