Giving Coffee a Break
False Alarms continued...
Nor does coffee appear to increase the risk of heart disease, according to a
10-year study of more than 85,000 women. In the February 1996 Journal of the
American Medical Association, Harvard researchers reported that women who
drank six or more cups of coffee weren't any more likely to have a heart attack
than women who drank only one or two cups.
Plenty of other alarms have turned out to be false. A few years back,
headlines warned about a possible link between coffee and breast cancer. But in
the February 1998 European Journal of Cancer Prevention, Italian
researchers reported finding no link. The other worry, concerning osteoporosis,
didn't hold much water either. Results of a study published in the June 1997
American Journal of Clinical Nutrition showed that bone thinning wasn't
more likely in women who drank coffee.
Jogging the Brain
The bottom line: Coffee seems to be harmless for most people. And studies
suggest that a cup may actually offer some impressive benefits. In the August
1999 issue of Physiology and Behavior, for instance, English researchers
reported that volunteers who drank caffeinated coffee in the morning performed
better than nondrinkers on tests that involved learning new information. That
holds true for the elderly as well, according to a study in the January 2002
issue of Psychological Science. And a study published in
International Journal of Sports Medicine in August 1999 found that
attention, psychomotor skills, and long-term memory all improved during the few
hours after volunteers drank caffeinated beverages.
Why? Caffeine keeps us alert not by speeding us up but by keeping us from
slowing down, according to Michael Bonnet, PhD, professor of neurology at
Wright State University in Ohio. Each time brain cells fire, they produce a
squirt of a chemical that serves as an "off" switch that keeps neural
activity in check. Caffeine, in effect, blocks the chemical -- jamming the
switch so that it can't be turned down.
Caffeine also may boost levels of brain-cell calcium, a mineral we know is
important in memory. In experiments reported in the October 1999 issue of
Proceedings of the National Academy of Sciences, an Israeli researcher
observed a calcium increase in brain cells exposed to caffeine.