Eating watermelons may help reduce high blood pressure, say researchers. A new study in Florida has found that natural compounds in the fruit appear to dilate blood vessels so the heart does not have to work so hard pumping blood around the body, the Daily Express reported. Study's volunteers who took a pill containing the chemicals every day for six weeks saw significant improvements compared to others who took a dummy pill. High blood pressure is blamed for half of all heart attacks and strokes in the UK.