Polyunsaturated fat is a type of dietary fat. It is one of the healthy fats, along with monounsaturated fat.
Polyunsaturated fat is found in plant and animal foods, such as salmon, vegetable oils, and some nuts and seeds. Eating moderate amounts of polyunsaturated (and monounsaturated) fat in place of saturated and trans fats can benefit your health.
Polyunsaturated fat is different than saturated fat and trans fat. These unhealthy fats can increase your risk for heart disease and other health problems.
How Polyunsaturated Fats Affect Your Health
Polyunsaturated fats can help lower your LDL (bad) cholesterol. Cholesterol is a soft, waxy substance that can cause clogged or blocked arteries (blood vessels). Having low LDL cholesterol reduces your risk for heart disease.
Polyunsaturated fats include omega-3 and omega-6 fats. These are essential fatty acids that the body needs for brain function and cell growth. Our bodies DO NOT make essential fatty acids, so you can only get them from food.
Omega-3 fatty acids are good for your heart in several ways. They help:
- Reduce triglycerides, a type of fat in your blood
- Reduce the risk of an irregular heartbeat (arrhythmia)
- Slow the build-up of plaque in your arteries
- Slightly lower your blood pressure
Omega-6 fatty acids may help:
- Control your blood sugar
- Reduce your risk of diabetes
- Lower your blood pressure
How Much Should you eat?
Your body needs some fat for energy and other functions. Polyunsaturated fats are a healthy choice. The 2010 Dietary Guidelines for Americans makes the following recommendations on how much fat you should get every day:
- Get no more than 25% to 30% of your daily calories from fats. Make sure most of those fats are monounsaturated or polyunsaturated.
- Limit saturated fat (found in red meat, butter, cheese, and whole-fat dairy products) to less than 6% of your daily calories. For a 2,000 calorie diet, that's no more than 120 calories, or 13 grams of saturated fat a day.
Eating healthier fats can lead to certain health benefits. But eating too much fat can lead to weight gain. All fats contain 9 calories per gram. This is more than twice the amount of calories found in carbohydrates and protein.
It is not enough to add foods high in unsaturated fats to a diet filled with unhealthy foods and fats. Instead, replace saturated or trans fats with healthier fats. Overall, eliminating saturated fats is twice as effective in lowering blood cholesterol levels as increasing polyunsaturated fats.
Reading Nutrition Labels
All packaged foods have nutrition labels on them that include fat content. Reading food labels can help you keep track of how much fat you eat a day.
- Check the total fat in one serving. Be sure to add up the number of servings you eat in one sitting.
- Look at the amount of saturated fat and trans fat in a serving -- the rest is healthy, unsaturated fat. Some labels will note the monounsaturated and polyunsaturated fat contents. Some will not.
- Make sure most of your daily fats are from monounsaturated and polyunsaturated sources.
- Many fast food restaurants also provide nutrition information on their menus. If you DO NOT see it posted, ask your server. You also may be able to find it on the restaurant's website.
Making Healthy Food Choices
Most foods have a combination of all types of fats. Some have higher amounts of healthy fats than others. Foods and oils with higher amounts of polyunsaturated fats include:
- Sunflower seeds
- Flax seeds or flax oil
- Fish, such as salmon, mackerel, herring, albacore tuna, and trout
- Corn oil
- Soybean oil
- Safflower oil
To get the health benefits, you need to replace unhealthy fats with healthy fats.
- Eat walnuts instead of cookies for a snack. But be sure to keep your portion small, as nuts are high in calories.
- Replace some meats with fish. Try eating at least 2 meals with fish per week.
- Sprinkle ground flax seed on your meal.
- Add walnuts or sunflower seeds to salads.
- Cook with corn or safflower oil instead of butter and solid fats.
Polyunsaturated fatty acid; PUFA; Cholesterol - polyunsaturated fat; Atherosclerosis - polyunsaturated fat; Hardening of the arteries - polyunsaturated fat; Hyperlipidemia - polyunsaturated fat; Hypercholesterolemia - polyunsaturated fat; Coronary artery disease - polyunsaturated fat; Heart disease - polyunsaturated fat; Peripheral artery disease - polyunsaturated fat; PAD - polyunsaturated fat; Stroke - polyunsaturated fat; CAD - polyunsaturated fat; Heart healthy diet - polyunsaturated fat
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U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 - 2020 Dietary Guidelines for Americans. 8th Edition. Updated December 2015. health.gov/dietaryguidelines/2015/resources/2015-2020_Dietary_Guidelines.pdf. Accessed May 5, 2016.
Review Date 4/24/2016
Updated by: Emily Wax, RD, The Brooklyn Hospital Center, Brooklyn, NY. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.