Blueberries, native to North America, are also known as whortleberries, bilberries and hurtleberries. They owe their deep blue color to flavonoids — natural compounds that protect the brain’s memory-carrying cells (neurons) from decay. Long used by Native Americans for medicinal purposes, antioxidant-rich blueberries are packed with B complex vitamins, vitamin C and vitamin A. During World War II, British pilots reported improved night vision after eating bilberry jam. Though this claim may have seemed bizarre at the time, it turns out that blueberries are full of anthocyanosides, a potent antioxidant that improves eyesight.