If you're reading this while sipping your second — or more — cup of coffee today, blame it on your genes.

Scientists say they've identified a genetic variation believed to curb people's appetite for coffee. The gene variant — known to scientists as PDSS2 — controls the production of proteins that helps caffeine get metabolized in the body.

Bottom line: your coffee addiction may be hard-wired.

Led by researchers at the University of Edinburgh, scientists asked more than 1,200 Italians and 1,700 people in the Netherlands how much coffee they consume. Then they compared the responses and genetic results for both groups.

People who had the gene variant drank about one cup less of coffee a day than those without it. Researchers suggest PDSS2 could slow down the body's metabolism of caffeine, allowing those coffee drinkers to need fewer cups to stay wired.

"Our results highlight a novel gene which regulates coffee consumption by regulating the expression of the genes linked to caffeine metabolism," the researchers reported in the journal Scientific Reports. "Further studies will be needed to clarify the biological mechanism which links PDSS2 and coffee consumption."

Coffee has been enjoying a bit of a healthy buzz lately, with other studies finding a link between drinking coffee and a reduction in the incidence of heart disease, Alzheimer's disease and type 2 diabetes. But other research shows it is linked to sleep problems and other health concerns.

Coffee ranks among the most widely-consumed drinks in the world — second only to water and tea, the researchers noted.

"Given its important health and economic impact, the underlying genetics of its consumption has been widely studied," they wrote in their report. "Despite these efforts, much has still to be uncovered."

"To Your Health" offers quick doses of health news several times a week.

Allie Shah • 612-673-4488

@allieshah