Lice could help prevent asthma
28 April 2009

Research on mice has shown that those carrying the most lice had calmer immune systems than uninfested rodents, which may have implications for studying the causes of asthma.

The study, published in the BioMed Central journal BMC Biology, adds to evidence supporting the so-called hygiene hypothesis, which holds that the rise in asthma and allergies is linked to ‘hyper-clean’ living.

The idea is that if the immune system is not properly primed in childhood, immune cells can react to harmless triggers such as pollen or dust. Bacterial and viral infections do not seem to be the priming factor so researchers have been focusing lately on parasites.

Joseph Jackson and colleagues from the University of Nottingham wanted to test real, wild mice, not hygienic lab mice that had been raised for generations in ultra-clean conditions. After trapping mice and studying their immune systems, they found that mice who were uninfested with the louse Polyplax serrata had much more excitable immune systems than the mice carrying a heavy load of lice.

Dr Elaine Vickers, Research Relations Manager at Asthma UK, said: ‘This research adds to the evidence that parasites and substances we’re exposed to very early on life might affect our risk of asthma later on. And that growing up in an overly-clean environment might increase our asthma risk.
 
‘However, this study was conducted in mice rather than humans, and the hygiene hypothesis is still a controversial idea that is far from proven. The best advice we can currently give to parents is not to smoke around their children and to make sure that the whole family has a balanced diet and gets plenty of exercise.’