We know there’s no cure for colds. But let’s try anyway

I have the cure for your cold. Boil a big bottle of red lemonade in a saucepan and drink it all while it’s piping hot. Or cut a clove of garlic in half, put it in your socks, and go to bed. And to cure a child’s congestion, squirt breast milk up their nose.

These are among some of the more obscure modern home remedies and folk "cures" for colds and flu, collected by The Irish Times from more than 20 people ranging in age from late-20s to mid-40s.

There is, of course, no known cure for the common cold. Most people know this. The debilitating nature of the illness, however, means that we’re inclined to give various remedies – heard (or misheard) from friends, family and the internet – a shot in the hope of reducing the symptoms and the lifespan of the virus.

One that many people swear by at the moment is to boil about eight cloves of garlic with a chunk of fresh ginger, simmer for about 30 minutes, take off the garlic skins, strain the water into a mug, squeeze in the juice of a lemon and add two tablespoons of manuka honey. Another suggestion, tongue-in-cheek, is to rub a lark’s tongue on the back of your left foot for three Tuesdays in a row, which will get rid of the cold by the fourth Tuesday, hinting that colds get better anyway; we just think that whatever concoction we took made us better.

Some people take antibiotics in the mistaken belief that they can cure a cold or a flu. They can’t, as both are caused by viruses, and antibiotics kill only bacteria. And this is leading, dangerously, to increased antibiotic resistance.

Prof Luke O’Neill is an immunologist and the academic director of the Biomedical Sciences Institute at Trinity College Dublin.

He was recently recognised as among the top scientific researchers in the world by the Thompson Reuters index. “Being cold probably doesn’t make you catch a cold, although there is some evidence that the virus prefers to live in colder droplets,” he says. “Colds are more common at this time of year because we’re indoors more, in closer proximity, and that makes it more infectious. Staying in good health reduces the chances of catching a cold or flu.” At best, he says, the claims around most of the commonly touted treatments have weak, if any, evidence to support them.

Honey:

One of the most commonly documented cold treatments in Irish folk tradition is honey, and manuka honey is popular now. “Manuka honey does have particular antibacterial properties, but the cold is caused by a virus,” says O’Neill. “There are some indications that it might be a little helpful, but reliable trials have not been conducted.”

Echinacea:

This plant was widely used in Native American folk medicine, and has long been proclaimed as both a way to avoid catching cold and flu and as a means to cure them, although Native Americans never used echinacea to avoid colds. “There have been lots of trials for echinacea,” says O’Neill. “But the overall opinion is that those trials are not robust enough. The best evidence is that echinacea may, perhaps, shorten the length of time of a cold by, on average, half a day to a day. The effect is marginal; it’s probably harmless, but there are some clinical concerns that it is not harmless in children.”

Garlic:

Garlic in your socks. Chew on a raw garlic clove. Garlic tablets taken every day. “There’s some evidence that garlic might shorten the time of a cold, but a trial attempting to measure this may be ropey: different people get over colds in different amounts of time,” says O’Neill.

Vitamin C:

There’s a widespread belief that vitamin C both cures and prevents colds and other ailments. It’s bunkum. The belief originated with Nobel prize winner Dr Linus Pauling, but more than 30 trials involving 11,000 colds have shown that Pauling’s tests were flawed and that vitamin C has no effect beyond, possibly, very mild relief of cold symptoms.

Zinc and chillies:

“Zinc and capsaicin, the chemical found in chillies, have killed the cold virus in test

tubes, but a virus lives in your cells so it’s not as straightforward in humans. There is some evidence of both having antiviral properties and helping the immune system, but at most they may shorten a cold’s lifespan,” says O’Neill.

Vicks:

Menthol rubs and Vicks First Defence are not folk cures, of course, but many people swear by them. The menthol, or a spray, moistens the nose, which makes it less likely that the virus will stick and get in. There may also be a psychological effect at play here, according to O’Neill.

Whiskey, hot drinks and happiness:

A hot toddy for the grown-ups, flat 7-Up or red lemonade for the young ones. “Nobody has funded a clinical trial with flat 7-Up, but maybe it makes you feel a bit better, and there is something to be said for the immune system working better if you are in good form or feel you are being looked after,” says O’Neill.

“A hot whiskey may also reduce stress and, in doing so, boost the immune system, but drink it in moderation. The whole field of psychoneuroimmunology shows that endorphins and laughter boosts the immune system, so watching a funny film may help you get better.”

Dr Nuala O’Connor, a Cork GP and clinical lead for the Irish College of General Practitioners in Healthcare Associated Infections and Antimicrobial Resistance, says people are probably wasting their money on a lot of “cures”.

“There is no evidence for anything other than rest, paracetamol and lots of fluids, and allowing time for the body’s natural immune system to fight viral infections. Cough and sneeze suppressants should be taken only at night to aid sleep, as coughing and sneezing are your body’s way of flushing out the virus.

“People can be sick for two or three days, take an antibiotic or other treatment, and think that was the magic bullet, when in fact that was the timeframe of the illness.”

The best way to avoid catching and spreading colds is, she says, by not coughing and sneezing everywhere and, most importantly, regular handwashing.

How do we know whether we're fighting a cold or flu?

“With flu, you don’t usually get a runny nose but, within 24 hours, you won’t be able to get out of bed because of severe muscle pain and high fever, and it may take a week to 10 days to pass.”

O’Connor recommends the flu vaccine, especially for people in high-risk categories such as elderly people, immunosuppressed people, diabetics, asthmatics and pregnant women.

O’Connor is involved in a new HSE initiative, UnderTheWeather.ie, which gives a timeline of how long symptoms may last, what people can do to help themselves, and when to seek help if there is an underlying problem.

She stresses that a website can never replace a face-to-face check-up and that it is particularly important for elderly people or children under two to be checked out if there is a worry.