A form of polyunsaturated fat. Polyunsaturated fats are one of four basic types of fat (the others are cholesterol, saturated fat, and monounsaturated fat) that the body derives from food. While diets rich in some fats increase the risk of heart disease and other health problems, the omega 3-fatty acids are recognised as important for good health, reducing the risk of heat attack and stoke, slowing the progression of atherosclerosis and reducing inflammation is diseases such as rheumatoid arthritis and lupus. They are found primarily in coldwater fish.