Technical Abstract: Renewed interest in the health functionality of blueberry (i.e., Vaccinium species with blue surface color) has led to research in several areas including neuroscience, cardiovascular health, cancer chemoprevention and aging. This article reviews these new directions in blueberry research, with emphasis on in vivo studies, and will be of interest to those involved in horticulture, food science, and biomedical sciences. The antioxidant activity and polyphenolic constituents of blueberry, and polyphenolic bioavailability and response to processing, are also summarized.