Elderberries have long been used as an immune-system booster and studied for flu-fighting properties. Loaded with antioxidants, the dark purple berries have been prized as a natural health promoting food since ancient times. Hippocrates, known as "the father of medicine," described elderberries as a "medicine chest" for the variety of illnesses he believed it treated. A great way to enjoy the benefits of elderberries, especially during flu season, is in hot elderberry tea. Find the recipe here.