NEW YORK, Nov 13, 2000 (Reuters Health) - People who enjoy several cups of
filtered coffee each day may be putting themselves at increased risk of heart
disease, preliminary study findings suggest.
Daily consumption of a liter of paper-filtered coffee was associated with a
roughly 20% increase in homocysteine levels after 2 weeks, according to the
report published in the November issue of the American Journal of Clinical
Nutrition. Homocysteine, a compound that is produced when the body metabolizes
protein, is a risk factor for heart disease.
However, the association between coffee and heart disease remains unclear,
the authors stress.
"We conclude that drinking large quantities of coffee raises homocysteine in
(blood)," Dr. Rob Urgert from the Wageningen Centre for Food Sciences in the
Netherlands, and colleagues write. "Whether this raises the risk of
cardiovascular disease is not yet certain," they add.
Previous studies have found that heavy consumption of unfiltered, boiled
coffee might raise homocysteine levels.
To investigate whether filtered coffee had a similar effect, researchers
measured homocysteine levels in a group of people aged 18 to 53 who drank a
liter of coffee each day for 4 weeks, and in a group of people who did not drink
coffee.
Then, individuals in the coffee-drinking group abstained from coffee and
those who did not drink coffee consumed a liter a day for the next 4 weeks. The
researchers again measured homocysteine in their blood.
Levels of homocysteine rose in all 26 individuals after the weeks of
drinking coffee, but the researchers point out that most people do not drink the
10 to 15 daily cups of coffee consumed by study volunteers.
"Both unfiltered and filtered coffee appear to contain a factor that raises
plasma homocysteine," Urgert and colleagues write. "This factor is potentially
also present in soluble (instant) coffee, espresso, and other types of coffee,
but this will remain uncertain until the responsible compound is identified."
