Sweet dreams for coughing children

“Honey is better at treating children’s coughs than an ingredient used in many over-the-counter medicines”, The Daily Telegraph reported today. The Guardian , The Times and Channel 4 news also covered a recent study that found honey was more effective than dextromethorphan - the “active ingredient” in many cough remedies - at cutting the severity and frequency of nighttime coughing and aiding children in getting to sleep.

The news reports also mention that honey has been used “for centuries” to treat coughs, and that is has antiseptic, antioxidant and antimicrobial effects.

These reports are based on a study in 105 children that compared honey, dextromethorphan and no treatment on nocturnal coughs. The results give some indication that honey may at the least be as effective as dextromethorphan - a cough suppressant found in many over-the-counter cough syrups - for soothing children’s coughs in the short term. However, larger studies are needed to confirm these results, and to investigate whether honey’s apparent benefits are long-term, and particularly whether it can reduce how long a cough lasts.

The study examined the soothing properties of honey, and the authors did not investigate, or make any claims about, antimicrobial properties that honey may or may not have.

It is also important that any cough at night that is persistent, in children or adults, is not suppressed and ignored, but is given medical attention. Honey is also not recommended for children under one year because of a small risk of botulism.

Where did the story come from?

Dr Ian Paul and colleagues from Pennsylvania State University carried out this research. The study was funded by a grant from the National Honey Board, which is an agency of the US Department of Agriculture. The study was published in the peer-reviewed medical journal Archives of Paediatric and Adolescent Medicine .

What kind of scientific study was this?

This was a randomised controlled trial designed to compare the efficacy of honey, dextromethorphan, or no treatment, for soothing nocturnal cough and improving sleep quality.

The researchers enrolled 130 children with coughs, aged between 2 and 18 years, who attended the same paediatric clinic in Pennsylvania. To qualify, the children needed to have had a runny nose and cough for up to seven days. Children whose symptoms were thought to be caused by conditions other than an upper respiratory tract infection, such as asthma, allergies, or pneumonia, were not included. The researchers also excluded children who had recently taken medicine containing dextromethorphan or antihistamines, but included children who had taken medicines such as ibuprofen or paracetamol.

Parents were asked to rate how frequent their child’s cough had been on the previous night, and how much it had disturbed the sleep of both parent and child. The frequency was rated on a scale from zero (not at all) to six (extremely). Only children whose cough was rated as a three on at least two of these questions were included in the final group.

Eligible children were randomly assigned to one of three groups: a group that received a dextromethorphan syrup artificially flavoured to taste like honey, another that received buckwheat honey, or a group that received nothing. All groups received their assigned treatment in an opaque 10 ml syringe in a brown envelope, so that the study investigators did not know what each person was receiving. Parents and children did not know whether the syrup they were receiving contained honey or dextromethorphan.

Children were given a dextromethorphan dose suitable for their age (the syrup containing slightly more dextromethorphan than a normal over-the-counter preparation). Parents were told to give their child the medicine up to 30 minutes before the child went to sleep that night. The next day, the parents were telephoned, and again asked to rate the frequency and severity of their child’s cough during the previous night, and to rate their child’s and their own sleep disturbance because of the cough. Again, the researchers did not know which treatment the child had received.

Of the 130 children enrolled, 105 completed the study. The researchers then compared improvement in cough frequency and sleep disturbance between the first (untreated) and second (treated) nights for the three groups.

What were the results of the study?

The researchers found that honey improved the children’s cough frequency by 1.9 points on the seven point parent-rated scale  - better than the improvement seen with dextromethorphan (1.4 points) or no treatment (0.9 points). Honey also improved the sleep of both child and parent, and reduced severity and “bothersomeness” of the cough to the child more than dextromethorphan or no treatment.

When the groups were compared statistically as pairs, honey was found to be significantly better than no treatment at reducing cough frequency, but not at improving the severity, “bothersomeness”, or the sleep of either child or parent. None of the differences between honey and dextromethorphan were large enough to be significant, nor were the differences between dextromethorphan and no treatment.

Few side effects were seen, but 5 of the 35 children treated with honey experienced mild hyperactivity, nervousness and insomnia, while 2 of the 33 children treated with dextromethorphan experienced these symptoms, and no children in the no treatment group. The parents of one child taking honey reported drowsiness, and two parents reported stomach ache, nausea, or vomiting.

What interpretations did the researchers draw from these results?

The researchers concluded that, overall, honey was the most effective treatment for cough caused by upper respiratory tract infection when compared with dextromethorphan or no treatment.

They suggest that further studies should be encouraged, and that “each clinician should consider the findings for honey, the absence of such published findings for DM, and the potential for adverse effects and cumulative costs associated with the use of DM when recommending treatments for families”.

What does the NHS Knowledge Service make of this study?

There are a number of points to bear in mind when interpreting this study:

• Although the questionnaire that the researchers used to assess the children’s cough was reported to have been tested previously and shown to be reliable, it is still difficult to interpret what the improvements seen actually mean in practical terms. For example, it is difficult to say from the figures exactly how much more sleep the parents and children got, or how much less frequent the child’s coughing was.
• The measures of coughing and sleep used in this study were all based on parents’ subjective reports. Although the researchers did try to avoid biasing results by blinding the parents, children, and interviewers as to the treatment received, the parents whose children received empty syringes would have been able to tell that they had not received any treatment, and this may have biased their reporting. However, this should not be the case with the comparison of dextromethorphan and honey.
• The study was relatively small, which means that it may not be able to decide whether or not smaller differences between treatments occurred by chance or not. A larger study would be better able to detect whether the differences between honey and dextromethorphan were significant.
• This study only gave the treatments for one night, it is not known if similar effects would be seen if given on subsequent nights, or whether honey would reduce the overall duration of the cough.
• The authors suggest that the type of honey used may be important, as the buckwheat honey used in this study is a darker honey, and darker honeys tend to contain more antioxidants.
• It is not clear how honey might have an effect on cough, and the authors suggest several possibilities, including its antimicrobial or antioxidant properties, or even that the sweetness of honey may cause an increased salivation and production of airway mucus, thus soothing the throat. It is not possible to tell from these findings whether it is honey in particular that produces the soothing effects, or whether similar results would be seen if a another thick, sweet, liquid had been used instead, e.g. golden syrup.
• This study has only examined honey’s effect of soothing the throat during an upper respiratory tract infection and has not directly investigated any possible antimicrobial properties that honey may or may not have. The authors did not make any claims about its use in treating the infectious cause of coughs and colds.
• The authors point out that honey is not recommended for children under one year because of a small risk of botulism.

Overall, this study does give some indication that honey may at least be as effective as dextromethorphan syrup for soothing children’s coughs. However, larger studies looking at the longer-term use of honey and its effect on how long a cough lasts are needed.

As a final point, it is important that any nocturnal cough that is persistent, in children or adults, should not be suppressed and ignored but should be given medical attention.

Sir Muir Gray adds...

So my mother was right, yet again.