While expatriates with allergies may have to access antihistamines or other treatments through international medical insurance policies, they could be at a lower risk of developing brain tumours than the general public.
The investigation, which took place at Ohio State University and was led by associate professor of epidemiology Judith Schwartzbaum, found the protection an allergy causes was more pronounced in women than in men.
It found people with blood samples that had allergy-related antibodies in them were almost 50 per cent less likely to have developed glioma than those without evidence of allergies.
Glioma refers to a broad category of spinal cord and brain tumours that originate from glial cells.
Around 42 per cent of all brain tumours are gliomas, while 77 per cent of all malignant brain tumours are.
This form of cancer can suppress a human's immune system, enabling it to grow, but researchers have never been able to determine if allergies cut cancer risk or if gliomas interfere with the immune response to allergens.
Many previous investigations into the issue by international healthcare experts involved patients with gliomas self-reporting their allergies, with this study the first of its kind to involve the use of blood samples collected two decades before the tumour was diagnosed.
It found females who had high levels of allergen-specific immunoglobulin E (igE) were 54 per cent less likely to develop glioblastoma when compared with women who tested negative for the substance.
Among men, elevated amounts of igE were found to be linked with a 25 per cent smaller chance of glioma than those with normal levels.
"It could be that in allergic people, higher levels of circulating antibodies may stimulate the immune system, and that could lower the risk of glioma," Ms Schwartzbaum argued.
"There is definitely a difference in the effect of allergen-specific igE between men and women – and even results for total igE suggest there still may be a difference between the sexes," she continued.
However, the specialist noted the reason for the discrepancy is not yet known.