Study confirms link between paracetamol use and asthma

A high intake of paracetamol may increase the risk of asthma, especially among women, confirms a study published in the journal "American Journal of Respiratory and Critical Care Medicine."

The increase in asthma rates in industrialized countries is mainly attributed to changes in lifestyle, childhood, remember Graham Barr, of Columbia University in New York, and colleagues. This is what is called the hygiene hypothesis. According to proponents of this theory, improving hygiene and the development of antibiotic consumption in covers protect young children from exposure to infectious agents, alter the development of the immune system and promote the development of type allergic responses, including asthma part.

But the authors also point out that the increase in asthma also coincides with the United States, with the use of acetaminophen in the '70s and '80s, especially in children. After several cases of Reye's syndrome has been described in this country, health authorities recommend use paracetamol aspirin to children under 16 years. Indeed, the onset of this acute illness of the child and young teenager, rare (0.08 cases per 100,000 children) and potentially fatal, characterized by brain and liver damage, is favored by the use of aspirin in viral infections.

The link between asthma and paracetamol consumption is not established with sufficient rigor (simple association rather than genuine relationship of cause and effect), the researchers analyzed data from the Nurses' Health Study, a prospective study of 121 700 adult women. This analysis was to determine whether the number of asthma cases diagnosed (ie newly emerged) was linked to the consumption of paracetamol.

In 1990, participants were asked about the frequency of their use of acetaminophen, aspirin, and the only other non-steroidal anti-inflammatory drugs (NSAIDs). New diagnoses of asthma were then recorded for the next six years.

The analysis of data indicated that the risk of asthma is diagnosed in a woman is significantly associated with more frequent use of paracetamol (regardless of age, ethnicity, socio-economic status, the 'body mass index, smoking, consumption of other analgesics and taking a hormone replacement therapy).

Thus, for women using acetaminophen more than two weeks per month, the risk of newly diagnosed asthma was 1.63 times compared to those who did not take, so that such an association does not appear with the use of aspirin.

The authors explain this observation by the fact that paracetamol, reducing the levels of glutathione in the lungs, predispose to bronchospasm (bronchial spasmodic contraction). Paracetamol also promote oxidative stress, since glutathione, which converts free radicals into stable molecules, acts as an antioxidant.

While these results suggest that the increase in asthma could be partly attributed to an increase in the consumption of paracetamol, it is clear that many asthma patients tolerate this well analgesic, the authors note.

According to them, it would be premature to recommend that asthmatics avoid paracetamol. Further studies are needed, especially in children, to identify the profile of people likely to develop asthma when they consume a lot of paracetamol.