Researchers look at caffeine-processing gene, effects of coffee

Those with the genetic defect process caffeine up to four times more slowly.
LOS ANGELES TIMES
An extra cup of coffee increased the risk of a first heart attack in people with a defect in the gene responsible for breaking down caffeine, researchers reported Tuesday.
But people with a normal caffeine-processing gene could drink as much coffee as they liked with no added heart attack risk, scientists said.
Coffee is among the most widely consumed beverages in the world, and Americans spend more than $17 billion a year on lattes, cappuccinos and just plain joe.
The report in the Journal of the American Medical Association helped explain why earlier studies on the health effects of coffee produced conflicting results. None of the other studies looked at genetic differences among coffee drinkers.
Comparison
The study compared 2,000 people who had suffered a first heart attack to an equal number of healthy people. Participants in the study were asked about their coffee consumption and tested for a mutation in the caffeine-processing gene, the CYP1A2 gene.
People with the genetic defect process caffeine up to four times more slowly than people with a normal gene, said Ahmed El-Sohemy, a University of Toronto researcher involved in the study.
Caffeine causes blood vessels to constrict, which can trigger an increase in blood pressure.
The study was conducted in Costa Rica, where a member of his team had been performing other research.
Researchers found that people with the defect who drank two to three cups of coffee daily faced a 36 percent increased risk of a first heart attack. Those consuming four or more cups of coffee had a 64 percent higher risk.