Allergies Linked To Lower Risk Of Brain Cancer

People with a history of allergies and related diseases have nearly a third lower risk of developing a certain brain cancer than those without the condition.

Atopic diseases, which include asthma, eczema, hay fever, and other allergies, have been linked to a lower risk of glioma, a type of brain cancer that affects glial cells. This association has not been seen with meningioma, a tumor that develops in the membrane that covers the brain.
Eleni Linos of the Harvard School of Public Health in Boston and colleagues analyzed eight studies conducted between 1979 and 2007 that examined the association between a history of atopic diseases and a diagnosis of glioma or meningioma.
The researchers found that patients with a history of allergies had a 40 percent lower relative risk of glioma than those without allergies, and patients with a history of eczema or asthma had a 30 percent lower risk. They found no such association with meningioma.
While there is no evidence that the association is causal, "These results are consistent across many geographic settings, study designs, and different atopic diseases and may reflect a protective effect of the immunologic milieu associated with atopic allergy on tumor growth," the authors write.