If your favorite order at Starbucks is the “red-eye,” you can thank genetics for your ability to slog down all that caffeine without the shakes.
In a new study, scientists identified eight genetic variants that could partly explain why some people drink coffee by the pot, while others avoid the stimulating beverage altogether. By outlining the genetic foundation for coffee consumption, scientists believe they can find firmer evidence to support the positive — and negative — health effects of the popular beverage.
Researchers from the Harvard School of Public Health and Brigham and Women’s Hospital investigated the genomes of 120,000 European and African American coffee drinkers along with data on how many cups a day they consumed, using findings from dozens of previous studies. Their statistical analysis revealed six new gene variants that governed coffee consumption, and reaffirmed the presence of two others previously discovered by the same group of researchers.
The team identified variants in or near genes that play roles in learning, caffeine metabolism, blood pressure regulation and addiction. Two newly discovered variants, near the genes BDNF and SLC6A4, reinforce the positive effects of coffee’s molecular properties. For example, BDNF is involved in the release of pleasure-inducing neurotransmitters like serotonin and dopamine.
Researchers published their findings Tuesday in the journal Molecular Psychiatry.
Participants in the study that inherited five or six of the gene variations were more likely to be heavy coffee drinkers — four or more cups a day — than those who inherited just one or two, the Boston Globe reports. People with more coffee gene variants may drink more because they metabolize it quickly; thus, they enjoy coffee’s stimulating effects for a shorter period of time.
Some of the same gene variations seen in heavy coffee drinkers are risk factors for smoking initiation and obesity. Both obesity and smoking may be fueled by addiction, which could explain why some people can’t stop at just one cup. Researchers plan to dig deeper into the genetics of coffee drinking to see how variants may be positively and negatively affecting coffee fanatics’ health.
In the debate about whether coffee is good or bad for your health, genetics could cut through the noise and someday offer more definitive answers.
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