June 26, 2006 — -- Millions of Americans rely on a morning caffeine jolt to get their day started -- but your cell phone may be having a similar effect.
Exposure to the electromagnetic fields emitted by cell phones excites the brain in a small but measurable way, reveals a new study published in the Annals of Neurology. However, scientists aren't quite sure yet if the temporary excitment is a good or bad thing.
"If you drank a cup of coffee you would probably get a similar or greater effect than what's seen here," said Dr. Alvaro Pascual-Leone, professor of neurology at Harvard Medical School.
Scientists fitted 15 men between the ages of 20 and 36 with a modified helmet that placed a cell phone against their left ear. They turned on the cell phone for 45 minutes and compared the brain activity to when they wore the helmet without the cell phone turned on. They did not know when or if the phones were on.
They found that cell phone exposure increased cortical brain activity on the left side, where the phone was activated. In other words, the brain was more ready to respond to a stimulus. The cortical area of the brain is responsible for many functions including movement and language. In this study, the researchers measured how "ready" a subject's brain was to move his or her thumb.
"It changes how active the cells are or how ready they are to fire," said Pascual-Leone.
Neurons, or brain cells, use charged ions such as sodium and potassium to transmit, or "fire," an electrical signal. Pascual-Leone explains that cells have a baseline firing rate at rest, which reflects how ready they are to perform an action.
At this point, scientists cannot say if this increased activity is good or bad. The results are too preliminary.
"What it means is uncertain. Anytime you can affect brain activity it can be good or bad," said Dr. Michael Macken, assistant professor of neurology at Loyola University Chicago Stritch School of Medicine, who specializes in epilepsy.
For example, doctors have used electromagnetic fields to treat depression and migraines. But certain conditions such as epileptic seizures are caused by increased cortical activity.
"A concern is that this could have potential impact with people with epilepsy, but I certainly wouldn't be running scared at this point," said Macken.
Concerns about cell phone safety have grown as they become more widely used. According to CTIA-The Wireless Association, an international association for the wireless telecommunications industry, the number of cell phone subscribers has jumped from 38 million to 215 million since 1996.
People have filed lawsuits claiming that cell phones caused brain tumors and others complained of symptoms such as rashes, fatigue and digestive problems -- all lumped into the term "electromagnetic hypersensitivity."
CTIA has responded to such health concerns by funding research through the Food and Drug Administration investigating the possible harmful effects from wireless technology.
"We believe this issue needs to be guided by science," said Joe Farren, public affairs director at CTIA.
To date, scientific studies have not shown that wireless technology is harmful, according to the World Health Organization.
Given how many people use cell phones, researchers believe its worth looking into cell phone use and brain activity further, but it is too early to jump to any conclusions.
"The study is interesting, but doesn't tell us if the cell phone is a bad thing." said Dr. S. Claiborne Johnston, associate professor of neurology and epidemiology at University of California, San Francisco. "We shouldn't change any behavior at this point."