MONDAY, Dec. 9, 2002 (HealthDayNews) -- American and German researchers say they've found the genetic basis for the jitters that come with your java.
People with two linked genetic variations are far more likely to suffer caffeine-induced anxiety than other people, says the study, which was presented yesterday at the American College of Neuropsychopharmacology's annual meeting in San Juan, Puerto Rico.
It's the first study to identify why people have different behavioral reactions to the same drug. Not only does it provide new insight into why caffeine affects people in different ways, the study also validates a testing method that may help identify individual differences in how people respond to a number of major drugs, the researchers say.
The study was done by researchers from the University of Chicago and two German universities. They studied 94 healthy, infrequent caffeine users. The subjects were given either oral doses of caffeine or a placebo, and the researchers recorded the subjects' physiological reactions and their mood states.
Blood samples were also collected from the study participants and checked for the genes that code for two proteins, called adenosine receptors, that are known to interact with caffeine.
The researchers found four genetic variations of the adenosine receptors in the study group. After analyzing their results, they found that people with two specific variants in the A2a receptor gene had much higher levels of anxiety after consuming caffeine than other people in the study.
Previous studies found that people who suffer from panic disorder are likely to have one of the same variants. Caffeine is a common trigger of panic attacks in people with panic disorder.
The researchers plan to use the same testing method to study how people react differently to amphetamines.
More information
Here's where you can find more information about the health effects of coffee.
