Could a cure for the common cold be on the horizon?
As days get shorter and temperatures go down, many of us will find ourselves fighting off well-known cold symptoms, including a sore throat, a runny nose, coughing and blocked sinuses.
Whilst a common cold can leave you feeling under the weather, you can almost always treat it at home without seeing a GP. Advice from the National Institute for Health and Care Excellence (NICE) and Public Health England (PHE) advises the public to buy 'self-care' products from the pharmacy, instead of expecting antibiotics which are of no use for common colds as they don't kill viruses.
"There are many old wives' tales out there about how to manage colds," says Dr Sara Kayat, GP. "Some of these do have a medical basis to them, and others less so."
So, what natural remedies do we tend to reach for, and is there any evidence that they work?
This herbal remedy has traditionally been the treatment of choice for treating colds over the winter months. It is believed that the herb boosts the immune system by increasing white blood cells which fight infections and reduces many of the symptoms of a cold. However, "the evidence is mixed as to whether it works", says Dr Kayat.
A Cochrane review found that some studies showed that it may reduce the length of time colds last and relieve symptoms. But others showed it did not work. Dr Kayat adds: "More robust research is needed before the effects of echinacea on preventing or treating colds can be concluded."
Honey and lemon
Lemon and honey may work in a number of ways, says Dr Kayat. "Firstly, you are taking in fluids, which is important when you are ill. Secondly, you are also getting vitamin C from the lemon. Several studies show that vitamin C can reduce the duration and severity of a common cold.
"And thirdly, the honey may offer a boost of energy and a soothing element for a sore throat.
"Honey is also thought to have antibacterial properties, although this may not be helpful in a viral infection. If you heat the lemon and honey, the steam may also offer some help in reducing the congestion," she says.
Ginger has been used for medicinal purposes for centuries and is thought to soothe a wide array of ailments due to its active compounds, which include gingerols and shogaols. Studies have shown that these compounds have anti-inflammatory and pain-relieving properties, which may help reduce symptoms, including a sore throat.
"Ginger does have some anti-inflammatory properties, which may help with the symptoms of the common cold," advises Dr Kayat.
Garlic has antimicrobial and antiviral properties that may help the immune system fight viral infections and relieve the common cold. One study randomly assigned 146 participants to either a garlic supplement or a placebo over three months. People who took the garlic reduced the risk of catching a cold by more than half and also recovered faster.
According to Dr Kayat, "The evidence for the use of garlic in managing a cold is limited, but in theory it has antimicrobial properties which may help in fighting a cold."
If you have a bleeding disorder, take blood thinning medication, or are pregnant then garlic supplements should be avoided because it may increase the risk of bleeding.
According to Dr Riccardo Di Cuffa, GP, if you have a healthy balanced diet then additional zinc should not be required. "Foods rich in zinc include nuts, seeds, eggs, dairy products like cheese, meat and whole grains. Too much zinc can be harmful so be careful with supplements as some people report unpleasant side-effects," he says.
Menthol, which is included in many over-the-counter-medicines, is the essential oil that comes from mint plants, says Dr Di Cuffa. "There is limited medical evidence that menthol is effective at easing congestion. Some people do find it relieves blocked sinuses and congested airways making you more comfortable and able to breathe more freely.
"It can be applied to your skin or pillow with a rub purchased from pharmacists or inhaled via a humidifier or hot water steam inhalation over a sink, by adding a few drops of essential oil. But don't apply essential oils directly to the skin as they can irritate and cause a reaction."
There is evidence to suggest that vitamin D is useful for preventing a cold. "The body gets vitamin D from certain foods (like eggs, oily fish and red meat) and from skin exposure to sunlight," says Dr Di Cuffa. However, levels in most foods are low, and vitamin D formation in the skin doesn't happen in the UK between October and April, as sun isn't strong enough.
"The evidence is not conclusive, but vitamin D may help with a cold as a good immune system support. It’s generally agreed that most people should get enough vitamin D from their diets in the spring and summer months, but that you should take a supplement during the autumn and winter months in the UK. If you're concerned, speak to your GP to get advice." Certain groups, including pregnant women, over-65s and anyone who is housebound or who covers up for religious reasons, should take a supplement all year round.
Probiotics can have health benefits during periods of illness and can help keep your gut healthy. "Your immune system is linked to your gut, so a healthy gut will generally mean a healthier immune system," says Dr Di Cuffa.
"Probiotics are live bacteria that can be found in yoghurt and other fermented foods, like pickle, kefir and some cheeses." You can also buy a wide variety of probiotic supplements.
Speeding up your recovery when you're under the weather
According to Dr Kayat, the best way to manage a common cold is to let it run its course. "If you need to rest, rest. But if you feel well enough to get up and go for a walk, there is evidence to suggest that light exercise may boost your immune system."
She recommends staying hydrated by drinking plenty of water. "A balanced diet, and foods high in antioxidants like vitamin C and omega 3, will also boost your immune system."