People with allergies appear to be less likely to develop glioma, a type of tumor that starts in the brain’s glial cells. This link has shown up so consistently, in studies across several countries, that researchers now say it’s unlikely to be a coincidence. What they don’t know yet is why, and nothing suggests you should change how you treat your allergies.
This guide summarizes the main studies, what they can and can’t tell us, and the questions researchers are still working on. For more, see our living with allergies guides.
Jump to: Quick answer · Key studies · The blood-test evidence · What it doesn’t mean · Possible explanations · FAQ
Quick answer
- A consistent link: a 2007 analysis of eight studies found people with allergies had about 39% lower risk of glioma.
- Confirmed in a large international study: in 2016, respiratory allergies were linked to about 30% lower glioma risk among more than 8,700 people.
- Blood tests point the same way: higher allergy antibody (IgE) levels in blood stored years before diagnosis were linked to lower glioma risk, even 20 or more years beforehand.
- No link was found for meningioma, a different, usually noncancerous brain tumor.
- It’s an association, not a treatment. Keep treating your allergies as your doctor recommends.
What the main studies found
| Study | Who | Findings |
|---|---|---|
| Linos et al., 2007, Journal of the National Cancer Institute (meta-analysis) | 8 studies: 3,450 people with glioma and 1,070 with meningioma | Glioma risk was lower with a history of allergy (relative risk 0.61) and asthma (0.68). No overall link with meningioma. The authors judged the pattern unlikely to be explained by bias alone. |
| Amirian et al., 2016, Cancer Epidemiology, Biomarkers and Prevention (Glioma International Case-Control Study) | 4,533 people with glioma and 4,171 without, from 14 sites in 5 countries | Respiratory allergies were linked to about 30% lower glioma risk (odds ratio 0.72), including for high-grade glioma. Asthma and eczema were also linked to lower risk. |
| Schwartzbaum et al., 2012, Journal of the National Cancer Institute | Stored blood from 594 Norwegians later diagnosed with glioma and 1,177 matched people without | High total IgE was linked to lower glioma risk (odds ratio 0.75), and the link was present 20 or more years before diagnosis. |
The 2016 authors concluded that the accumulated evidence makes the link “unlikely to be coincidental” and that research can now shift toward understanding the biology behind it.
Why the blood-test evidence matters
Most allergy and cancer studies ask people with a brain tumor to remember their allergy history, which can be unreliable, especially for someone who is ill. The Norwegian study avoided that problem. It measured IgE, the antibody involved in allergic reactions, in blood donated years earlier and stored in a serum bank, long before anyone had symptoms.
Because the link was still there 20 or more years before diagnosis, it’s unlikely that an early, undetected tumor was simply lowering allergy levels. That strengthens the case that something about allergic immune activity, or the people who have it, is related to lower glioma risk.
What this research doesn’t mean
- It doesn’t prove allergies prevent brain tumors. These are observational studies that show associations.
- It doesn’t mean you should avoid allergy treatment. No study has shown that treating allergies raises glioma risk in a way that should change your care.
- It doesn’t apply to all brain tumors. The 2007 analysis found no overall link with meningioma.
- It doesn’t tell you your personal risk. The studies report relative differences between groups, not anyone’s individual chance of developing a tumor.
If you have new, persistent headaches, seizures, vision changes or other neurological symptoms, see a doctor, whatever your allergy history. If you’re wondering whether your symptoms are allergies at all, read adult-onset allergies and cold vs allergies.
Possible explanations researchers are exploring
The studies above don’t establish a mechanism. The Norwegian authors discuss a few possibilities:
- Immune surveillance: the lower cancer risk in people with allergies has been attributed to the immune system watching for and clearing potentially cancerous cells, and higher IgE might help remove precancerous cells before a tumor forms.
- A regulatory role for IgE: total IgE helps keep mast cells in balance, and mast cells can dampen immune responses.
- Early tumor effects: a developing tumor could distort immune measurements close to diagnosis. That’s why the finding 20 or more years before diagnosis matters.
The 2016 authors noted that understanding the mechanism could open new paths for immunotherapy or cancer prevention. For more on how the immune system shapes allergies, see parasites, allergies and the hygiene hypothesis.
This guide is general information, not medical advice. Read our medical disclaimer.
Frequently asked questions
Do allergies lower the risk of brain tumors?
People with allergies have a lower risk of glioma in many studies: about 39% lower in a 2007 meta-analysis and about 30% lower for respiratory allergies in a 2016 international study. The link wasn’t seen for meningioma.
Does this mean allergies prevent cancer?
No. The studies show an association, not cause and effect, and they’re specific to glioma.
Should I stop taking allergy medicine?
No. Nothing in this research suggests changing your allergy treatment. Keep following your doctor’s advice.
What is a glioma?
A glioma is a tumor that starts in the brain’s glial cells. Glioblastoma is the most common glioma subtype.
What is IgE?
IgE is the antibody the immune system makes in allergic reactions. Higher levels in stored blood were linked to lower glioma risk years later.
Sources
- Linos E, Raine T, Alonso A, Michaud D. Atopy and risk of brain tumors: a meta-analysis. J Natl Cancer Inst. 2007;99(20):1544-1550.
- Amirian ES, Zhou R, Wrensch MR, et al. Approaching a scientific consensus on the association between allergies and glioma risk: a report from the Glioma International Case-Control Study. Cancer Epidemiol Biomarkers Prev. 2016;25(2):282-290.
- Schwartzbaum J, Ding B, Johannesen TB, et al. Association between prediagnostic IgE levels and risk of glioma. J Natl Cancer Inst. 2012;104(16):1251-1259.
Last reviewed: October 21, 2026.
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