Study confirms link between paracetamol and asthma
An EU-funded study has confirmed the link between regular paracetamol use and asthma in European adults. Over recent years, studies in the UK and US have uncovered evidence of a link between paracetamol and asthma, and research has also revealed that asthma is more common in countries with higher paracetamol sales. However, this latest study, published in the European Respiratory Journal, is the first to draw on data from across Europe. The scientists compared over 500 asthma patients in 12 European centres with the same number of healthy individuals of a similar age who came from the same area as the patients. Study participants underwent tests for allergy and asthma symptoms and were asked how often they took paracetamol and other pain killers such as aspirin and ibuprofen. The results reveal that adults who take paracetamol at least once a week are almost three times more likely to have asthma than people who take the drug less often. The use of other painkillers did not appear to be linked to an asthma diagnosis. 'These data add to the increasing and consistent epidemiological evidence implicating frequent paracetamol use in asthma in diverse populations,' the researchers write. These findings raise the question of how paracetamol might make someone more prone to developing asthma. One possible explanation is that paracetamol reduces levels of an antioxidant substance called glutathione in the lungs. Glutathione plays an important role in protecting the airways from the damaging effects of air pollution and tobacco smoke. 'Considering asthma is a common disease and paracetamol use is infrequent, it is now important to find out whether this association is really a causal one,' commented Dr Sief Shaheen of Imperial College London in the UK, the lead author of the study. 'A clinical trial may be the only way to answer this question conclusively.' EU support for the research came from the GA2LEN ('Global allergy and asthma European network') project, which is financed through the 'Food quality and safety' Thematic area of the Sixth Framework Programme (FP6). Previous research by GA2LEN has demonstrated a link between a Mediterranean diet during pregnancy and low levels of asthma in offspring. It highlighted the importance of breastfeeding and a good early diet in protecting children from allergies. GA2LEN researchers were also present in Beijing during the recent Olympics, studying the prevalence of asthma among European athletes. The findings will also be presented at the forthcoming annual congress of the European Respiratory Society, which will be held in Berlin, Germany, in early October.