It's rare that anyone in Los Angeles can sit through a meal or a meeting - let alone an entire commute - without the chirp of a cell phone or digital device interrupting. In fact, we can hardly imagine how we muddled through without a mobile phone to aid in an emergency, to send word if we're running late, or to get some extra work done between meetings or during drive time.
But these electronic helpers have been in the center of a storm of debate over whether they might contribute to brain tumor risk. Most of the studies have not shown a relationship between cell phone use and the occurrence of benign or malignant brain tumors for 10 or more years of cell phone use. However, concerns have been raised about an increased risk in the highest users. So, what's a cell phone user to do? When it comes to your brain and your health, it's better to be safe than sorry.
Fortunately, being safe is an easy fix: Use a wired earpiece or speaker feature when talking on a cell phone. That advice comes not only from my own conclusions after looking at the data, but from a leading neurosurgeon and brain tumor expert, my colleague Keith Black, M.D., who heads our Department of Neurosurgery at Cedars-Sinai and the Maxine Dunitz Neurosurgical Institute.
Dr. Black uses a wired earpiece himself, and encourages his patients to do the same.
There are a few more simple precautions I would recommend, but first, let's take a look at some of the available facts.
Cell phones emit radio frequency energy, or RF, as they send signals to cell towers. These waves are in the lower frequencies of the electromagnetic spectrum and are not a form of ionizing radiation like X-rays which can alter cellular DNA. However, since cell phones are generally pressed directly against the head - and for many, for hours at a time, there have been concerns that the radiation may penetrate the skull and over time change the molecular structure of brain tissue. (That goes for wireless headsets like Bluetooth, too.)
Studies that have sought to prove this link have generally been negative. In May, the long-awaited results of the INTERPHONE study were published in The International Journal of Epidemiology. INTERPHONE was a 10-year, 13-country study, the largest and longest to date. It examined whether extensive cell phone use increases risk for brain tumors. The study showed no increased risk for the two most common forms of brain cancer - glioma and meningioma.
Although a small proportion of study participants, the highest users of cell phones, demonstrated a slightly increased risk of glioma, the authors call this finding inconclusive and instead say that further study is necessary.
And it is. There are a few problems with the INTERPHONE research. The study was conducted between 2000 and 2004, and defined "heavy" cell phone usage as those who spent about 30 minutes a day on their phones. Use of cell phones -- especially among young people -- has skyrocketed. According to the Cellular Telecommunications and Internet Association, there were more than 285 million cell phone service subscribers in 2009, compared to 110 million users in 2000. Not only are there more people using cell phones, they're talking longer. More and more people have turned off their land lines, and turned to their mobiles, yakking an average of 21 minutes a day -- meaning many people talk much longer than that.
Despite being a relatively new study, INTERPHONE is already outdated, not only in terms of the amount of usage, but in the ways we use our phones. There was no way to account for Bluetooth technology, and the effects of a wireless, RF-emitting device that is kept directly in the ear -- often for lengthy periods of time.
Additionally, the study was based on interviews, which tied accuracy to the recollections of the subjects interviewed. There is a certain "recall bias" in the studies currently available. That is, those who have brain tumors are more likely to exaggerate their use of cell phones and of always holding the phone on the same side, than those who do not have brain tumors. Understandably, people want an explanation of why their tumors may have developed.
But that doesn't necessarily help the cause of science.
The INTERPHONE study also focused on people over the age of 30, in part because it wanted to examine those with a long history of cell phone use. This means there is no information available on how cell phones affect the developing brains of their youngest -- and some of their most frequent -- users.
That's why it's best to limit cell phone use for children until the long-term effects have an opportunity for study. Texting is also a preferable alternative as that helps you hold the device further away from your body.
On a positive note, despite the marked increase in cell phone use, between 1987 and 2007, there was no increase in the age-adjusted incidence of brain and other nervous system cancers, which supports the data suggesting that there is no cause-and-effect association. Nevertheless, in the absence of conclusive scientific evidence that high volume, long-term use of cells phones is safe, protecting your brain is, well, a no-brainer. The wired headpieces might not look slick trailing out of your sleek iPhone, or have the Star Trek appeal of a Bluetooth, but they might help protect your most valuable possession: your brain.