Dr. Alberto Ascherio of Harvard told CNN that while there have been plenty of recent smaller studies on the benefits of coffee, there are so many variables in consumption that it is unlikely there will be any controlled trials involving large numbers of people in the near future.
The cost, Ascherio added, would also be prohibitive because the pharmaceutical industry doesn't sell coffee and would be unlikely to foot the cost for a major research project.
The medical community is somewhat split on the benefits of coffee. While it is rich in antioxidants, for example, it also carries a jolt of caffeine that doesn't agree with many people and can become fattening if laced with too much cream and sugar.
As it stands now, doctors are inclined to leave coffee consumption up to the individual. "If you consume coffee, enjoy it," Dr. Donald Hensrud of the Mayo Clinic said. "I wouldn't necessarily recommend taking it up if you don't like it."