The reference that you provide in the Journal of Inorganic Biochemistry does in fact support the benefits of green coffee based ingredients such as caffeine, chlorogenic acid, and a group of polyphenols and fiber type compounds with health benefits that includes cell health benefits. In general, this type of research shows up positive health benefits including, as you say, blood sugar management, energy and metabolism, focus and cognition.
That's right, my dear @lmo; this natural product offers us many benefits, however it is traditionally taken after roasting coffee and many of us love to enjoy it.
Very grateful for your valuable support and your excellent commentary.