University of Illinois Extension

What are polyunsaturated and monounsaturated fats?

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Polyunsaturated and monounsaturated fat are both unsaturated fats. “Poly” means many unsaturated chemical bonds and “mono” means one unsaturated chemical bond. These unsaturated fats are often found in liquid vegetable oils.

  • Polyunsaturated oils are liquid at room temperature and in the refrigerator. Common sources of polyunsaturated fat are safflower, sesame and sunflower seeds, corn and soybeans, many nuts and seeds, and their oils.
  • Monounsaturated oils are liquid at room temperature but start to solidify at refrigerator temperatures. Canola, olive, and peanut oils, and avocados are sources of monounsaturated fat.
  • Both types of unsaturated fats may help lower your blood cholesterol level when used in place of saturated fat in your diet. Remember to be moderate in your intake of all types of fat.
  • Poly- or monounsaturated oils — and margarines and spreads made from these oils — should be used in limited amounts in place of fats with a high saturated fat content, such as butter, lard, or hydrogenated shortenings.
  • By substituting monounsaturated fat in your diet for saturated and polyunsaturated fats you may be able to keep HDL cholesterol levels high and LDL cholesterol levels low. Overall the highest intake of fat should be from the monounsaturated type (12 – 20 percent of total calories).

Tips for replacing saturated fats with unsaturated fats

  • Use oils containing monounsaturated fat like olive oil, canola oil, peanut oil, and sesame oil, instead of oils high in saturated fat like coconut oil and palm oil.
  • Use oils high in polyunsaturated fats like corn, soybean, safflower, sunflower, and cottonseed oils instead of coconut oil, palm oil, or hydrogenated vegetable fats.
  • Use liquid oils instead of butter, lard, or hardened vegetable shortening.
  • Eat foods high in unsaturated fats like fatty fish (salmon, mackerel, tuna) instead of meats high in saturated fat.
  • Incorporate foods high in polyunsaturated and monounsaturated fats like avocados, nuts, and olive oil into your salads instead of using products high in saturated fats like mayonnaise based dressings.
  • Try the new plant-sterol margarine products.

Trans Fat - Foods high in trans fat also raise blood cholesterol. “Trans” is also a word that refers to the chemical structure of certain unsaturated fats when they have had hydrogen added to them to make them firm. Foods with the words “partially hydrogenated vegetable oils” in their ingredient list are likely to be high in trans fat. Baked goods, snack foods, fried foods, margarines, and shortenings often contain trans fats. The best way to find out if a food contains trans fat is to look on the Nutrition Facts label or look for partially hydrogenated fat in the ingredients list.

Tips for Reducing Trans Fat Intake

  • Look for processed foods made with unhydrogenated oil rather than hydrogenated oil or saturated fat. If it doesn’t say “hydrogenated” or “partially hydrogenated,” it is unhydrogenated fat.
  • Use margarine as a substitute for butter, and choose soft (liquid or tub) margarines over harder, stick forms. Use margarine and other products that contain liquid vegetable oil as the first ingredient and no more than two grams of saturated fat per tablespoon.
  • Look for trans fat information on the Nutrition Facts label and choose products with no trans fat added.

Consuming Excess Calories – Eating too many calories leads to weight gain. Weight gain can raise your LDL cholesterol levels, triglyceride levels, and blood glucose levels.

Back to: Eating for Cardiovascular Health

This document is a source of information only, and is not medical advice.