The study, led by Brown University in Rhode Island, USA, drew on data from tens of thousands of people who had previously participated in four other broad health studies.

They found that patients whose bloodstreams were filled with immunoglobin E (or IgE), which is the antibody the body produces to fight many allergies, were also statiscally speaking less likely to developing a brain tumour, and if they did, would tend to survive longer.

“In terms of fighting the cancer or preventing it from growing, people who have allergies might be protected. They might be able to better to fight the cancer,” said one of the study co-authors Dominique Michaud, associate professor of epidemiology at Brown University, in a press release.

The results need to be taken with a grain of salt, it seems, with a couple of annomalies appearing in the data.

For instance, while the appearance of tumours lessened significantly for patients with slightly elevated levels of IgE, the same was not true for those patients with much higher levels of the antibody, which means there is either a failure somewhere in the data, or we simply don't understand enough about why IgE appears to have this protective effect.

Also, of the thousands of people included in the data, only 159 went on to develop brain tumours. These people were compared against a control group of over 500.

Still, this study is not without precedent. Earlier this year, a team at Chicago conducted a similar study into the glioma-fighting qualities of allergies, and also found that it had a positive effect on patients.

In any case, while it's not clear how or even whether it's this allergy-produced antibody doing the good things, it seems more and more likely that allergies might actually have an upside

[Brown University]