Both monounsaturated and polyunsaturated fats come from vegetables and plants They are easier for your body to digest than saturated fats. Besides being heart-healthier than saturated fats, they are thought to reduce our risk of heart disease, enhance memory, and other mental functions.

Monounsaturated fats are one type of unsaturated fat. These are liquid at room temperature, but solidify at cold temps. Some studies have shown that these kinds of fats can actually lower LDL (bad) cholesterol and maintain HDL (good) cholesterol.

Foods that contain monounsaturated fat are: avocado, olives and olive oil, almonds and almond butter, cashews and cashew butter, peanuts, peanut butter and peanut oil, sesame seeds.

Polyunsaturated Fats are the second type of unsaturated fat. They are also liquid at room temperature. This type of fat has also been shown to reduce levels of LDL (bad) holesterol, but too much can also lower your HDL (good) cholesterol.

Foods that contain polyunsaturated fat are: walnuts, corn oil, some tub margarines, sunflower oil, pumpkin and sunflower seeds, some salad dressings.

Additional Resources:

http://www.americanheart.org/presenter.jhtml?identifier=3046644#as_long_as_i_eat
http://www.americanheart.org/presenter.jhtml?identifier=3046644