Which at-home hacks to ward off cold and flu actually work?

Although many people swear that munching on vitamin C tablets can ward off colds and flu, there is no good evidence for that.

“Studies have shown people under extreme physical stress, like athletes or people in extremely cold temperatures, do benefit from taking supplements of vitamin C,” Harnett says. For the rest of us, so long as we are eating fruit, results are marginal. “It’s likely to only reduce the duration of the cold for half to one day.”

Besides, says Harnett, because vitamin C is essentially ascorbic acid, it may not be great for our teeth.

Probiotics

All that chicken soup people drink when they’re sick? That’s partly for the veg, vitamins and protein, but it’s also for the bone broth, which promotes good bacterial growth in the gut. Yoghurt with live active cultures is similarly beneficial. Good gut bugs are central to a healthy immune system. “A healthy gut microbiome can send anti-inflammatory and virus-fighting signals to the immune system,” says Anna Debenham, an accredited practising dietitian.

As for the thousands of probiotic pills and powders, there is promising evidence for the role of some strains, like Lactobacillus paracasei and Bifidobacterium bifidum in shortening – or preventing – the common cold, though researchers are still nutting out optimal dose and duration.

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“They may even help boost our immune response when you have your influenza vaccine,” says Dr Jennifer Hunter, a GP and director of Health Research Group.

The key? Check with your pharmacist or naturopath which strain has been studied and is backed by research.

Zinc

An important mineral for immunity, a recent review – led by Hunter and the National Institute of Complementary Medicine Health Research Institute – found zinc supplements can reduce the duration of a cold or respiratory infection by about two days and may support the body against more severe illness.

Hunter explains that zinc has antiviral properties: “Even in healthy young adult males, 15 milligrams of oral zinc daily boosted their immune systems within 24 to 48 hours by activating white blood cells.”

Zinc supplements in doses higher than the recommended daily intake should only be taken for short durations. “Seven to 10 days is OK,” says Hunter, “but longer term, it requires medical supervision as it can lead to copper deficiency.”

Echinacea

This flowering herb may stimulate the immune system to more effectively fight infection, and a review of the evidence found it may decrease the duration and severity of acute respiratory tract infections. “Evidence suggests it might be helpful in prevention,” Harnett adds.

However not all supplements are equal, Harnett says: “A really simple thing to do is to ask ‘has this particular formulation of echinacea had a clinical trial? Has it been studied?’”

ArmaForce

A combination of the herbaceous plant andrographis, zinc, echinacea and olive leaf, ArmaForce was a popular supplement in the home toolkits of many during COVID-19.

“Studies around andrographis shortening symptoms of the common cold are good,” says Harnett. But there are concerns that it’s not without side effects – loss of taste can occur after about two weeks of use. For this reason, short-term use, while you have symptoms, is recommended.

Honey

A sweet remedy for sickness, sucking on a teaspoon of honey can soothe the throat and act as a gentle cough suppressant. When stirred into a lemon and ginger tea, it also helps to keep fluids up.

“It has some lovely properties, particularly Manuka for its antimicrobial properties,” Hunter says. “It’s a pretty safe thing for people to be using.”

A 2021 review Hunter was involved with also found it helpful in reducing severity of coughs, particularly for kids.

Garlic

A stinky but smart approach, chewing on some raw garlic may help to ward off the flu (and keep those around you maintaining social distance).

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A Cochrane review, conducted in 2021, found garlic – with its antiviral properties – had the best evidence, among natural medicines, for the prevention of influenza. It’s not clear how much raw garlic you’d need to eat, but some research suggests three to four cloves a day may be beneficial.

The active compound in garlic, allicin, starts to break down when cooked, so if you turn your nose up at eating whole garlic cloves, you could make pesto, aioli, or add it to your salad dressing. Or try a garlic supplement.

And the rest of it

Sleep, when our body heals and restores itself, is perhaps the best natural remedy there is. Exercise, provided it’s not extreme, lowers stress levels and boosts antibodies and white blood cells, thereby supporting the body to fight infection.

The third part of this health trinity is food.

“To work efficiently, your immune system relies heavily on a range of nutrients being readily available within the body,” explains Debenham. To prevent a deficiency in nutrients that support immune function – vitamin D, vitamin C, zinc, iron and vitamin A – incorporate these foods every week: garlic, berries, kiwi fruit, green leafy veggies, broccoli, oily fish (e.g. salmon, sardines), eggs, nuts, Greek yoghurt, chickpeas and oats.

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