Is decaf coffee more healthy than normal coffee? A study by University of Florida researchers in 2006 documents that almost all decaffeinated coffee contains some measure of caffeine.

Caffeine is the most widely consumed drug in the world. UF researchers report in Journal of Analytical Toxicology said “If someone drinks five to 10 cups of decaffeinated coffee, the dose of caffeine could easily reach the level present in a cup or two of caffeinated coffee,” said co-author Bruce Goldberger, Ph.D., a professor and director of UF’s William R. Maples Center for Forensic Medicine. “This could be a concern for people who are advised to cut their caffeine intake, such as those with kidney disease or anxiety disorders.”

Scientists analyzed 12 samples of Starbucks decaffeinated espresso and brewed decaffeinated coffee taken from a single store. The espresso drinks contained 3 milligrams to 15.8 milligrams of caffeine per shot, while the brewed coffees had caffeine concentrations ranging from 12 milligrams to 13.4 milligrams per 16-ounce serving.

“One has to wonder if decaf coffee has enough, just enough, caffeine to stimulate its own taking,” Gold said. “Certainly, large cups and frequent cups of decaf would be expected to promote dependence and should be contraindicated in those whose doctors suggested caffeine-free diets.”

And even moderate caffeine levels can increase agitation, anxiety, heart rate and blood pressure in some susceptible individuals, Goldberger said. “The important point is that decaffeinated is not the same as caffeine-free,” Griffiths added. “People who are trying to eliminate caffeine from their diet should be aware that popular espresso drinks such as lattes (which contain two shots of espresso) can deliver as much caffeine as a can of Coca-Cola – about 31 milligrams.”