The Largest Study Showing That Mobile Phones Do Not Increase Brain Tumor Risk

The risk of brain tumors with mobile phone use, overall, by subtype or by tumor location, did not increase, Journal of the National Cancer Institute reported in a prospective study. 

The researchers studied a large UK cohort of women over a 14-year follow-up period. The findings showed no increase among mobile phone users in the risk of any brain tumor or the main malignant subtypes (glioma and glioblastoma).

A Study Involving 1.3 Million Participants

Between 1996 and 2001, researchers enrolled women born between 1935 and 1950, totaling 1.3 million participants. They were first asked about mobile phone use in the median year 2001 and again in 2011.

There were 776 thousand women who completed the 2001 questionnaire. At that time, 286 thousand participants had never used a mobile phone, 489,769 had used one, and 66,362 used a mobile phone daily.

In the 2011 questionnaire, 45.8% of participants who had been never-users in 2001 reported talking on a mobile phone for at least 1 minute per week. They said they had used mobile phones for an average of 4.3 years.

Results

During the 14-year follow-up, 3268 brain tumors were identified. The adjusted relative risk for all brain tumors in participants who had used a mobile phone compared with never-users was 0.97 (95% CI, 0.90 to 1.04). 

The relative risk was 1.15 (95% CI, 0.94 to 1.40) for right-sided tumors and 1.05 (95% CI, 0.85 to 1.29) for left-sided tumors.

The relative risks for regular users and never-users by tumor type were as follows:

• Glioma 0.89 (95% CI, 0.80 to 0.99)
• Glioblastoma 0.93 (95% CI, 0.82 to 1.06)
• Meningioma 1.01 (95% CI, 0.87 - 1.17)
• Pituitary tumors 0.94 (95% CI, 0.73 to 1.21)
• Acoustic neuroma 1.19 (95% CI, 0.89 to 1.59)

The researchers wrote, "there was no increase in the risk of brain tumors or any brain tumor subtype in people who had used mobile phones for at least 10 years, or in tumors of the temporal and parietal lobes, the most exposed parts of the brain".

In conclusion, this finding strongly supports the evidence accumulated so far that mobile phone use under normal conditions does not increase brain tumor risk. Future research should target particularly heavy mobile phone users while considering new features of continually evolving technology; therefore, advising mobile phone users on how to reduce unnecessary exposure remains a sound precautionary approach.