As report on our news feed, a new Danish study of over 350,000 people, published in the BMJ , has found no link between using mobile phones and an increased risk of cancers of the brain and central nervous system.
This is the strongest evidence yet to suggest that mobile phone use does not raise the risk of these cancers.
As we posted back in May, although there are still questions to be answered (especially about effects of using a mobile for more than 10 – 13 years), the weight of evidence so far suggests that people who use mobile phones are not at increased risk of cancer.
The new report goes some way towards answering some of the outstanding questions from previous studies.
Here’s a quick summary of its key points:
- This is the best evidence yet – a large prospective cohort study. This means the researchers followed a group of mobile phone subscribers over time, recorded new cases of cancer in this group, and compared this to cancer rates in the general population, rather than, for example, asking people who had already been diagnosed with brain cancers to remember how often they used their mobiles in the past.
- It followed people for around 10 years on average.
- It looked at different types of brain cancer, and found no increased risk for some of the types some previous studies had suggested may be linked to mobiles – such as glioma.
- The big criticism of previous studies – ‘recall bias’, or the fact that they relied on people remembering past events – doesn’t apply to this study.
And yet, as critics will doubtless point out, there are still questions to be answered:
- Mobile phone subscription data isn’t the same as hard data on mobile phone use – we need studies to include this data as well.
- 10 – 13 year follow up would still not be long enough to detect any really long-term effects, especially for slow-growing cancers, so researchers need to keep following up this cohort for longer.
- This study doesn’t tell us about the effects of mobile phone use in children.
So there’s still a need for further studies and analysis. But let’s remember that there is currently no proven way in which electromagnetic radiation from mobile phones can damage DNA or affect cell growth in a way that could plausibly lead to cancer.
- Frei P et al, Use of mobile phones and risk of brain tumours: update of Danish cohort study BMJ 2011;343:d6387 DOI: 10.1136/bmj.d638