Polyunsaturated fats are healthy fats found in plant foods and fish. Chemically, polyunsaturated fats are unique because they contain more than one double bond between carbon atoms. Eat foods rich in both polyunsaturated and monounsaturated fats. These types of fat have beneficial effects on your cholesterol levels. Check with your doctor before making any changes to your diet.
Low-density lipoprotein, or LDL, cholesterol can be harmful in your body. Your body uses LDL to carry cholesterol from the liver to the rest of your body. The cells throughout your body utilize the cholesterol to make new cells and repair damage. If you have too much LDL in the blood, it can attach to the walls in your arteries and cause plaque buildup. This can lead to atherosclerosis, heart attack or stroke. LDL is commonly referred to as the "bad" cholesterol. Your LDL cholesterol level is directly related to your diet. Unhealthy fats, such as trans fats and saturated fats, may actually increase the LDL in your body. Your doctor will check your cholesterol levels every five years if you are generally healthy. Ideally, your LDL cholesterol should be below 100 mg/dL, according to the American Heart Association.
High-density lipoprotein, or HDL, cholesterol is the beneficial "good" cholesterol that travels through your bloodstream. HDL roams through your body, picks up the excess LDL cholesterol and transports it to the liver. From there it is broken down and discarded. HDL cholesterol protects your body from chronic diseases and may lower your risk of heart disease. Your HDL level should be above 60 mg/dL.
Effects of Polyunsaturated Fat
Polyunsaturated fats do not raise the "bad" LDL cholesterol in your body and may actually help raise your HDL cholesterol. One type of polyunsaturated fat known as omega-3 fatty acid, is especially beneficial for your cholesterol levels. The Harvard School of Public Health reports that consuming polyunsaturated and monounsaturated fats, instead of a high amount of carbohydrates, may lower your blood pressure, improve cholesterol levels and reduce your risk of cardiovascular disease. For optimal heart health, 8 to 10 percent of your total calories should come from polyunsaturated fat.
Polyunsaturated fats are found in vegetable oils, such as corn and olive oil, as well as walnuts, sunflower seeds, pistachios and flaxseeds. According to a study published by the American College of Nutrition in 2007, consuming 2 to 3 oz. of pistachio nuts each day can improve your cholesterol and decrease your risk of coronary disease. Fatty fish, such as salmon, herring and tuna, contains omega-3 fatty acids.
While polyunsaturated fats have beneficial effects on your cholesterol, they are still high in calories. Each gram of fat provides 9 calories. The American Heart Association recommends limiting your fat intake to 25 to 35 percent of your total calories. Based on an 1,800 calorie diet, you should have 50 to 70 g of fat each day. Most of the fat you eat should be monounsaturated or polyunsaturated fat.
- Harvard School of Public Health: Fats and Cholesterol
- American Heart Association: Know Your Fats
- American College of Nutrition: Pistachio Nut Consumption and Serum Lipid Levels. Sheridan, Michael J, et al.; 2007