Vitamin C or echinacea are traditional cold remedies that may have been given to you by your parents when you were younger. But it turns out that supplements may actually be an effective way to treat a cold, according to a 2021 review that looked at the efficacy of zinc.
The research, published by BMJ Open, surveyed studies and found that zinc supplements might help to prevent and shorten colds and flu.
So could minerals and other “natural” remedies be effective at treating a cold? We take a look at the evidence below.
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The authors of the report surveyed zinc supplements taken as tablets or mouth sprays and found that they may help to shorten the length of a cold by an average of two days. By reviewing 28 studies involving nearly 5,500 people, the researchers found evidence to suggest that taking zinc could also reduce the risk of catching a cold in the first place.
They concluded that zinc might be a suitable option that doctors could recommend when patients ask for unnecessary antibiotics, which carry considerable risks and offer no benefit for viral infections.
How zinc might help to treat colds is not yet known, but a separate 2013 study from the Ohio State University suggested that the mineral may help to regulate the immune system and stop it going into overdrive.
However, what’s known about zinc is still preliminary, and researchers do not yet know the optimum dose to take to help your immune system. The NHS advises not to take more than 25mg of zinc a day, as high amounts of the mineral can reduce the amount of copper that the body can absorb, leading to anaemia and weakening your bones.
One of the best dietary sources of zinc is shellfish: your daily recommended intake can be provided with just two oysters. It is also found in grains, milk and meat.
Evidence shows that a vitamin C supplement may help to fight colds and flu, in certain circumstances. The vitamin is crucial to the proper functioning of your immune system but is easy to obtain through diet, given it is found in abundance in fruits and vegetables, meaning that few people could benefit from taking more in a supplement.
However, an exception to this is people in situations of high physical stress. A review from 2017, which looked at marathon runners, soldiers doing sub-Arctic exercises and skiers, found that vitamin C supplements could cut the risk of colds or flu in half. “Vitamin C can be used both as a precautionary measure and as a therapeutic treatment in strengthening the body’s defences,” says Dr Harald Stossier, the director of the exclusive Vivamayr Maria Worth health clinic in Austria. “If taken early enough, it can even prevent a virus-induced cytokine storm.”
After much hype over the course of the coronavirus pandemic, we may now be more aware of the importance of vitamin D for your immune system. A 2017 British survey found that vitamin D supplements could halve your risk of getting a cold or flu. It was particularly beneficial for people with a pre-existing vitamin D deficiency.
The NHS recommends that everyone in the UK, including children, take a vitamin D supplement from October to April each year. They recommend a dose of 10 micrograms a day, with no more than 100 micrograms for adults and 50 micrograms for children aged 10 and under.
Given the added benefit of vitamin D for building healthy bones, they also recommend a supplement all year round for children aged between one and four. Babies under one should also be given vitamin D if they are breastfed, or if they have less than 500ml of formula a day.
Several studies have found that honey can be used to help treat coughs and sore throats, including an Oxford review from 2020, which stated that it is “superior” to conventional treatments. The survey found evidence to suggest that honey can help to reduce the amount of coughing and its severity compared to other treatments or placebos. It could even help to reduce the length of symptoms by a day or two.
The study didn’t look into the best way to consume honey, but a traditional cold cure mixes a teaspoon of it with lemon juice and hot water to make a soothing drink.
Why honey is beneficial isn’t yet fully known by scientists, but it has been used as a medicine for thousands of years. It has antimicrobial properties, which could be helping to fight the cause of infection, or it could be due to the small amounts of antioxidants and minerals that it contains.
Remember that honey is not suitable for children under one due to the risk of botulism.
This article has been updated with the latest advice.
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