"A Wake-Up Call for Caffeine Addicts", Sci-Tech Today, March 8, 2006,
Link: http://www.sci-tech-today.com/story.xhtml?story_id=0200001C4OK4
The findings of a new medical study might be enough to make you spit
out your morning coffee. And that could be a good thing -- at least for
half of you.
A study of 4,000 coffee drinkers has found that two or more cups each
day can increase the risk of heart disease -- but only for those with a
genetic mutation that slows the break-down of caffeine in the body.
In diverse urban areas, the mutation is found in roughly half of all
people. People without the mutation can drink as much coffee as they
like with no added risk of a heart attack, the scientists said.
Unfortunately, there's no commercial test for the mutation, which now
puts coffee die-hards in a bit of a quandary.
"I don't know what to think," said Donna Carmichael, 50, as she waited
for a train at Union Station.
"How do you know if you've got the gene?" she said. She usually drinks
about three cups of coffee a day. "If it's genetic, though, who's going
to go out and get tested?"
The findings, published in the Journal of the American Medical
Association, could explain why previous investigations into caffeine's
effect on the heart have produced conflicting results. Some reports
have tied coffee to an increase in heart disease, while others have
found no effect.
Ahmed El-Sohemy, a University of Toronto scientist involved in the
study, said earlier reports failed to account for the genetic
differences among people.
"One size does not fit all," he said.
People who metabolized caffeine slowly and drank two to three cups of
coffee each day had a 32 percent higher risk of heart attack, according
to the study. Those consuming four cups or more had a 64 percent
greater risk. A single cup of coffee had no effect on heart attack
risk, researchers found.
How this will affect America's addiction to caffeine remains to be
seen. Coffee drinkers in the U.S. -- about half of all adults -- - gulp
an average of three cups of coffee daily and spend more than $17
billion a year keeping themselves fully caffeinated. The findings are
"interesting, plausible and worthy of further study," said Dr. David
Robertson, a professor of medicine and pharmacology at Vanderbilt
University.
But he said the results needed to be confirmed through additional
research and that consumers shouldn't worry about changing their
coffee-drinking habits.