Blue berries and other berries such as blackberries, strawberries, raspberries and cranberries are packed with antioxidants. Antioxidants help neutralize harmful by-products of metabolism called "free radicals" that can lead to cancer and other age related diseases. Researchers at the USDA Human Nutrition Center have found that blueberries rank #1 in antioxidant activity when compared to 40 other fresh fruits and vegetables.