The Differences Between Monounsaturated and Polyunsaturated Fats

Saturated fats have been shown to adversely affect certain aspects of your lipid profile and increase your risk of cardiovascular disease, which is why unsaturated fats—which have the opposite, positive effect—are preferred.

Unsaturated fats come in two types:

  • Monounsaturated fat
  • Polyunsaturated fat

Although they differ slightly, including both types in your diet can help improve your heart health and lipids.

Various cooking oils in glass bottles
cerealfoods / Getty Images

Monounsaturated Fats

Monounsaturated fats have only one double bond in their molecular structure. They may help in maintaining the overall health of cells. Further, they can lower bad cholesterol, which reduces the risk for heart disease and stroke in the long run.

Several healthy foods contain monounsaturated fats, including:

  • Cooking oils, such as olive oil, sesame oil, and canola oil
  • Peanut butter
  • Nuts, including peanuts and cashews
  • Avocados
  • Olives
  • Sesame seeds
  • Healthy spreads labeled “high oleic”

Polyunsaturated Fats

Polyunsaturated fats have more than one double bond in their structure. Much like monounsaturated fats, polyunsaturated fats can help lower "unhealthy" cholesterol. 

Polyunsaturated fats also contain omega-3 and omega-6 fatty acids, which your body needs for brain function and cell growth.

Foods high in polyunsaturated fats include:

  • Seeds, including sunflower seeds and pumpkin seeds
  • Cooking oils, including corn oil, safflower oil, and soybean oil
  • Nuts, such as pine nuts and walnuts

Omega-3 Fats

A certain type of polyunsaturated fat, omega-3 fats, have specifically been studied regarding their effects on heart health and ability to lower lipid levels.

Research shows omega-3 fats can lower triglyceride levels and slightly increase HDL (good cholesterol) levels. A 2016 study found eating fish high in omega-3 fatty acids at least twice a week significantly decreases blood triglyceride levels.

The following foods contain this specific type of polyunsaturated fat:

  • Fatty fish, including salmon, mackerel, herring, sardines, and tuna
  • Seeds, including flax seeds and chia seeds
  • Walnuts
  • Algae (e.g., seaweed, spirulina, nori)

A Word From Verywell

Despite the slight differences in their chemical structure, both types of unsaturated fat have been linked to promoting heart health by:

  • Improving lipid profiles
  • Modestly increasing HDL cholesterol
  • Helping lower LDL cholesterol and triglyceride levels

Studies have shown that replacing saturated fats and trans fats with foods containing mainly monounsaturated and polyunsaturated fats can help protect you against heart disease. The American Heart Association recommends this dietary approach.

Unsaturated fats are collectively referred to as “healthy fats” because they do not appear to promote the formation of atherosclerosis, a waxy plaque that may build up in the arteries.

Was this page helpful?
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Jenkins DJ, Chiavaroli L, Wong JM, et al. Adding monounsaturated fatty acids to a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia. CMAJ. 2010;182(18):1961-1967. doi:10.1503/cmaj.092128

  2. Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. Saturated fatty acids and risk of coronary heart disease: modulation by replacement nutrients. Curr Atheroscler Rep. 2010;12(6):384-390. doi:10.1007/s11883-010-0131-6

  3. MedlinePlus. Facts about polyunsaturated fats. Updated April 23, 2018.

  4. Raatz SK, Johnson LK, Rosenberger TA, Picklo MJ. Twice weekly intake of farmed Atlantic salmon (Salmo salar) positively influences lipoprotein concentration and particle size in overweight men and women. Nutr Res. 2016;36(9):899-906. doi:10.1016/j.nutres.2016.06.011

  5. American Heart Association. Saturated Fat.

Additional Reading