I'm not a doctor or a medical researcher so I'm not qualified to give medical advice.
I will say: Coffee is one of the oldest and most consumed beverages on Earth. It's also one of the most studied. As someone who consumes quite a bit of coffee and is pretty health conscious, I've researched the topic quite a bit (see WebMD for a medical perspective on the studies). The research I've read points to the benefits of coffee on everything from cancer prevention to elevated fitness performance. However, everything in moderation.
IANADB... there's an increasing raft of medical research pointing to the benefits of consuming coffee. Unfortunately, while there's some material comparing dark roasted to light roasted coffee, or instant to whole bean coffee, there isn't a ton of work done about coffee freshness. From where we sit, if you grant the cluster of purported benefits and their drivers, it's a rational stretch to think that the fresher the coffee, the greater then benefit. For example, if you're keen on the role of antioxidants in human health, you'd agree that as coffee loses its freshness, its essential compounds literally oxidize, thereby limiting the benefit. My personal suggestion to folks is that as new research comes out all the time, a good Google alert will keep you on top of the latest thinking!