There is an important role for research that sets up further research. Without these exploratory studies, it is difficult to determine where to make a larger investment in a more rigorous study.

You'll note that most papers are rather explicit about this, though this is often underplayed by journalists. The article does say this:

> Further research is still warranted to explore the underlying mechanisms and active compounds in coffee.

> If the association is further proved to be a causal effect, men might be encouraged to increase their coffee consumption to potentially decrease the risk of prostate cancer.”