In the midst
of concerns that the ubiquitous cell phone may be linked to brain cancer,
findings from two US studies indicate that cell phone users are at no
increased risk for the disease.
But the
findings are not a green light to gab all day, according to the authors of
both studies. They say their findings do not rule out a risk for brain cancer
with long-term cell phone use.
The fist
study, published in the December 20th issue of The Journal of the American
Medical Association focused on nearly 900 men and women aged 18 to 80, about
half of whom had brain cancer.
The
investigators found the risk was 20% lower among cell phone users compared
with non-users. What's more, the risk was lower for cell phone users who
talked more than 10 hours a month than for those who talked less than one hour
per month. Joshua E. Muscat of the American Health Foundation in Valhalla, New
York, led the study.
In an
interview with Reuters Health, Muscat noted that while the cell phone scare
has garnered much media attention, it has not pushed people to discard their
phones. And these findings suggest there may be little reason to do so.
"Most
people use their cell phones relatively infrequently," Muscat said.
"We found that typical levels of cell phone use are not related to brain
cancer."
However, he
noted, this study looked only at possible short-term effects--subjects had
used their phones for just under 3 years, on average. Long-range studies are
still needed, Muscat said.
In the second
study, a team of researchers led by Dr. Peter D. Inskip of the National Cancer
Institute in Bethesda, Maryland, compared the cell-phone use of nearly 800
patients with brain cancer to that of a similar number of healthy individuals.
They report
finding "no evidence that risks were higher among persons who used
cellular telephones for 60 or more minutes per day regularly for 5 or more
years," versus those who did not. The study was released in advance of
publication in the January 11th issue of The New England Journal of Medicine.
Cell phones
emit low levels of radiation that some animal research suggests may be
powerful enough to damage DNA. But, Muscat said, other evidence suggests the
radiation that may be absorbed from cell phones is not powerful enough to
inflict genetic damage on brain cells.
In addition,
he noted, if cell phone radiation triggers tumors, one would expect to find
them in brain areas near the ear, on the side the phone was typically held. In
this study, there was no such pattern.
Despite these
reassuring results, however, the jury is still out on cell phones and brain
cancer. Earlier this year, Swedish researchers linked cell phone use to an
increased brain cancer risk among more than 600 subjects. Around the same
time, the US Food and Drug Administration announced it would oversee
industry-funded research into the possible link over the next few years.
Muscat said
that while more studies are needed, he doubts long-term cell phone use will be
found to cause brain cancer. "We have little reason to believe it
does," he said, "but for now we simply don't know."
