With the cold winter weather firmly setting in, many people will go down with a nasty cough at some stage in the next few months.
From the irritating but persistent tickle at the back of the throat to the chesty bark, homes and offices rattle with the sound of rasping. But what's the best thing to do to soothe the airways?
Many will reach for their favourite cough syrup, but new research suggests that in the future they may cure a cough by going to the local sweet shop rather than the pharmacist.
Scientists at the National Heart and Lung Institute have found that theobromine -a compound found in chocolate -is more effective at treating coughs than codeine, which is used in many traditional cough mixtures.
'It's a chemical found in cocoa, which the Mayans used to call the Food of the Gods,' says the Institute's Dr Omar Sharif Usmani. 'We don't know how this drug works, but it seemed to dampen the cough reflex.'
However, for anyone thinking of stocking up on Dairy Milk, Usmani warns that a lot more research has to be done.
'This is very preliminary research. We only used a small number of people and the coughing was artificially provoked, so we need to see what effect it has on real patients.'
In the meantime, it seems it's back to the trusty spoonful of cough linctus -after all, that's fairly effective. Or is it?
A study into the effectiveness of cough remedies by Knut Schroeder and Tom Fahey at the University of Bristol concluded: 'Recommendation of over-the-counter cough medicines to patients is not justified by current evidence.'
The researchers looked at 15 trials of the various types of cough medicine -from 'antitussives' to treat dry coughs to 'expectorants' for chesty coughs with phlegm -and came to the conclusion that the pounds 100 million or so spent on over-the-counter cough medicines in the UK every year may be 'an unnecessary expense'.
'There is very little evidence for or against the efficacy of cough medicines,' says Schroeder. 'Some of the mixtures may well be effective, but it's not proven. It may be down to a placebo effect, but it may be down to an active ingredient. We just don't know.'
However, the Proprietary Association of Great Britain (PAGB), which represents the makers of over-the-counter remedies, says people have been treating themselves satisfactorily with cough medicines for decades.
PAGB research found that in 90 per cent of cases cough medicines were described as effective and 90 per cent of people would use the product again to treat the problem.
'Existing treatments do work,' says Fraser Woodward, a PAGB spokesman. …