DescriptionA new report singles out two fruits that could help prevent heart attacks and strokes. Researchers from the University of Alabama at Birmingham praised potassium in a study. Avocados and bananas contain high amounts of potassium. The researchers found mice who had more potassium had more flexible arteries. When people get older, their heart arteries tend to stiffen, causing heart attacks and strokes. As with all studies, this finding is not absolute and more research is needed.