Polyunsaturated fats are a type of dietary fat that contain multiple double bonds in their chemical structure. They are considered essential fats, meaning the body cannot produce them on its own and must obtain them from food. Common sources of polyunsaturated fats include fish, nuts, seeds, and vegetable oils like canola and sunflower oil. These fats are beneficial for heart health as they can help lower bad cholesterol levels and reduce the risk of heart disease. There are two main types of polyunsaturated fats: omega-3 and omega-6 fatty acids. Foods rich in omega-3 include salmon and flaxseeds, while omega-6 can be found in corn oil and soybean oil.