I've posted in the past about the many health benefits of drinking coffee. Whenever I do, readers ask if they can get the same health benefits from decaf. And some insist that decaf is better for you because, well..., no caffeine.
Caffeine, it turns out, does pose a slight health risk for some people. As I pointed out earlier, pregnant women should avoid it. In addition, too much caffeine can over-accelerate your heart rate or make it irregular, both no bueno if you've got heart disease.
Fortunately, many of the benefits of drinking coffee come from its hundreds of other natural compounds, especially antioxidants. All coffee, even decaf, has antioxidants which, for example, help prevent liver disease and reduce the risk of type 2 diabetes.
However, there are several health benefits of coffee that appear to be caused by the caffeine specifically, including: 1) improved cognitive function in older adults, 2) sharper memory, and 3) increased athletic endurance.
So the answer is: if you really want the FULL benefit of coffee, drink the real thing.
If you really want to maximize the benefits of drinking coffee, you should consider making your coffee with a dark roast rather than a medium or light roast. Dark roasts are less acidic than light roasts and therefore less likely to contribute to the formation of kidney stones. That's not a huge risk, but it is a risk.
Another advantage of dark roasts is that they contain less caffeine, which means you can drink your full allowance of four to six 8 oz cups a day without worrying about getting the jitters.
Personally, I've developed a taste for dark roasts because I think they make it easier to taste some of the naturally "nutty" flavor. They're bitter in the same way that walnuts are bitter.
If you're concerned about bitterness, consider getting a dark roast of a normally "smooth" variety, like Kona. It's expensive but worth it. What you do NOT want to do is try to bury the bitterness with sugar, creamer and additives, which more than negate any health benefit you'd otherwise be receiving.
Bottom line: as long as you're drinking it black, you get plenty of health benefits from either regular or decaf, but slightly fewer with decaf. If you're worried about too much acidity, choose a dark roast.