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Winter coughs: separating fact from fiction
As winter viruses spread, many reach for cough syrups or homemade remedies like honey and lemon. But do these treatments actually work? A respiratory medicine expert weighs in on what science says about soothing persistent coughs.
How cough medicines work
Most coughs stem from common colds, which must run their course naturally. While cough medicines cannot treat the underlying viral infection, they may ease throat irritation and reduce the urge to cough, according to Jacky Smith, a professor of respiratory medicine at the University of Manchester.
For dry coughs, syrups containing glycerol or other soothing agents can coat the throat, providing temporary relief from dryness. However, Smith notes that cheaper supermarket brands are just as effective as pricier alternatives.
One key consideration is sugar content-many cough syrups contain high levels, making sugar-free options a better choice for those monitoring their intake.
Active ingredients: do they deliver?
Many cough medicines advertise active ingredients like dextromethorphan, which claims to suppress the cough reflex. However, Smith says its impact is minimal. She warns that exceeding recommended doses can be risky, as dextromethorphan has addictive potential.
For chesty coughs, some syrups contain levomenthol, which creates a cooling sensation in the throat, temporarily masking irritation. Yet, Smith remains skeptical about the effectiveness of other common ingredients, such as guaifenesin, which is supposed to loosen phlegm but lacks strong scientific backing.
Sedating antihistamines like diphenhydramine may help with sleep but do not treat the cough itself. Similarly, plant extracts like thyme and squill show little evidence of benefit.
Homemade remedies: a viable alternative?
Smith suggests that for many, the best approach is patience-letting the cough run its course while staying hydrated. Lozenges can help by encouraging swallowing, which temporarily suppresses coughing.
A warm mixture of honey and lemon may be just as soothing for dry coughs as over-the-counter syrups. A Cochrane review, an independent analysis of medical evidence, found that honey and lemon could provide some benefit for children over one year old with coughs and colds.
When to let a cough do its job
Coughing is the body's way of clearing mucus, so suppressing it entirely isn't always helpful. For chesty coughs, spitting out excess phlegm can ease airway congestion. Smith advises against forcing suppression: "I will cough up whatever I need to. I won't try and suppress it-get it out."
Swallowing phlegm poses no harm, as stomach acids can break it down. However, if mucus appears dark brown, it may indicate blood, and medical attention should be sought.
When to see a doctor
Most chesty coughs resolve within a few weeks without antibiotics. However, if symptoms persist beyond three weeks, Smith recommends consulting a GP to rule out complications.
"Supplies of over-the-counter remedies may seem endless, but the evidence behind many is thin. Sometimes, the simplest solutions-like honey and lemon-are just as effective."
Jacky Smith, Professor of Respiratory Medicine, University of Manchester
