When scientists analyze fruits and vegetables for their antioxidant capability, blueberries rank among the highest in their capacity to destroy free radicals. Rich in antioxidants that combat oxidative stress and inflammation, blueberry extracts not only help preserve youthful cognitive function, but also help maintain healthy blood flow via several mechanisms, including maintaining already normal LDL levels and blood pressure within normal limits and preserving endothelial and vascular function. The two most active constituents found in blueberries are anthocyanins and pterostilbene. Blueberry anthocyanins are considered one of nature's most potent antioxidants. Pterostilbene is the other blueberry constituent that helps maintain healthy lipid and glucose levels that are already within healthy ranges. Through its unique biological effects and antioxidative potential, pterostilbene helps maintain healthy DNA structure.