Prunes are a super-food star! First of all, one single prune contains more than half a gram of fiber. Prunes also contain a natural laxative, diphenylisatin, which is why prune juice is often used for constipation. Prunes also help to lower cholesterol. They are great for lowering blood pressure, since they contain both potassium and magnesium.They are also a great source of iron, and can help to prevent Iron-deficiency anemia. Half a cup of prunes contains 3g of fiber, 320 mg Potassium, 19 mg Calcium, 16 mg Magnesium, 0.5mg Iron, 2mcg Folate, and 340IU of vitamin A. Also prunes contain Chlorogenic Acid which has been shown to reduce body weight. Plus, they are just great for snacking.