Buzzing About Caffeine – Researchers Find New Genetic Variants Linked To Coffee Consumption

Chuck Bednar for – Your Universe Online
If you’re the type of person who drinks several cups of coffee, it may not just be because you’re feeling tired or because you enjoy the taste – your habit may be linked to one of the six newly-identified genetic variants found to be associated with habitual consumption of the caffeinated beverage.
A new large-scale study published online Tuesday in the journal Molecular Psychiatry by researchers from Harvard School of Public Health and Brigham and Women’s Hospital and colleagues from the Coffee and Caffeine Genetics Consortium, found that the variants could also help explain why specific amounts of coffee or caffeine have different effects on different people.
According to Associated Press (AP) writer Malcolm Ritter, scientists had long known that a person’s DNA influenced how much coffee they consumed, but the new study is the first to pinpoint some of the specific genes responsible. They analyzed data from over 120,000 individuals looking for tiny variations in DNA which correlated with coffee consumption amounts.
Arielle Duhaime-Ross of The Verge said the findings “help explain why some coffee lovers bounce off the walls after a single cup, whereas others feel the need to invent alarm clocks that wake you up with a shot of espresso,” though Ritter noted the authors found no link between the genes and the intensity of a person’s taste for coffee.
Lead investigator Marilyn Cornelis, a research associate at the Harvard T.H. Chan School of Public Health, and her colleagues identified a total of eight genes linked to coffee consumption, although two of them had been previously identified by Cornelis and others in earlier studies. Two of the new genes were linked to metabolism of caffeine, two were associated to its psychoactive effects, and two were related to lipid and glucose metabolism.
The role of those last two genes in coffee consumption is currently unknown, and Cornelis said that they could warrant further investigation. In all, however, the newly-discovered variants explain roughly 1.3 percent of coffee-drinking behavior, and while that might not seem like a large amount, the researchers said that it is roughly equal to the percentage reported for smoking, alcohol consumption and other types of habitual behaviors.
“Coffee and caffeine have been linked to beneficial and adverse health effects. Our findings may allow us to identify subgroups of people most likely to benefit from increasing or decreasing coffee consumption for optimal health,” Cornelis said in a statement Tuesday. “The new candidate genes are not the ones we have focused on in the past, so this is an important step forward in coffee research.”
“The next question is who is benefiting most from coffee,” she told Harvard Gazette Staff Writer Alvin Powell. “If, for example, caffeine is protective, individuals might have very similar physiological exposure to caffeine, once you balance the metabolism. But if coffee has other potentially protective constituents, those levels are going to be higher if you consume more cups, so they might actually be benefitting from non-caffeine components of coffee. So it’s a little bit complex.”
While the researchers told Duhaime-Ross that they do not believe that their findings will change anyone’s current coffee consumption habits, the do feel that it will help doctors and nutritionists develop individualized caffeine consumption guidelines that have been optimized to a person’s specific genetic makeup.
Furthermore, Cornelis said that it will make it easier to study the health effects of coffee and solve some of the confusion about whether or not consuming the caffeinated beverage is good or bad for a person’s health. As The Verge reporter pointed out, even though drinking coffee is often viewed as a bad habit, it has been found to decrease a person’s risk of developing Type 2 diabetes, prostate cancer, and oral cancer.
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