They were so
addicted, they just could not give up their favorite daily
snack--not even in the interest of science.
lovers who flunked out of a Johns Hopkins University study
on aspirin and heart disease helped researchers stumble on
an explanation of why a little chocolate a day can cut
the risk of heart attack.
It turns out
chocolate, like aspirin, affects the platelets that cause
blood to clot, Diane Becker of the Johns Hopkins
University's School of Medicine and her colleagues
chocolate offenders taught us is that the chemical in
cocoa beans has a biochemical effect similar to aspirin in
reducing platelet clumping, which can be fatal if a
clot forms and blocks a blood vessel, causing a heart
attack," Becker said in a telephone interview.
The 139 so-called
chocolate offenders took part in a larger study of
1,200 people with a family history of heart disease. The
study looked at the effects of aspirin on blood
Before they got
the aspirin, the volunteers were asked to stay on a
strict regimen of exercise, refrain from smoking, and avoid
caffeinated drinks, wine, grapefruit juice, and
Chocolate and the
other foods are known to affect platelets.
"We knew they
would offend," Becker said. "Some people said to us,
'I can do anything but I can't stay off my chocolate.' "
"If people said,
'I will try my very best,' we said, 'OK, do your very
best, but it is crucial that you don't eat chocolate for 24
to 48 hours before you come in for testing.'"
Yet some people
failed even this test of self-control.
like, a chocolate chip. If they were going to eat it,
they ate some chocolate," Becker said.
"It went all the
way from a chocolate-chip cookie to someone who ate a
gallon of chocolate ice cream with chocolate chunks and two
chocolate-chip cookies at one sitting."
Becker cut them
out of the aspirin study but looked at their blood
platelet samples from both groups through a mechanical
blood vessel system designed to time how long it takes for
the platelets to clump together in a hair-thin plastic
The blood of the
chocolate eaters was slower to clot than the blood of
the volunteers who resisted chocolate, Becker told a meeting
of heart experts in Chicago.
In a urine test,
the chocolate lovers had lower levels of a platelet
waste product called thromboxane.
"Does it help a
little bit? Yes," Becker said. "But it does not have
anywhere near the magnitude of the effects of a single baby
aspirin a day."
Becker's team wants to study the effects of eating chocolate
on a "free-living" population of volunteers. They will
measure how much chocolate people eat and then watch
them for several years to see if chocolate-eaters have
a different rate of heart attacks, stroke, and heart
have suggested that dark chocolate contains more of the
beneficial compounds linked with heart health, and experts
note that the high sugar and fat content of most
chocolate candy might cancel out some of the benefits.