Manage cholesterol levels through dietary fats
February 26, 2013
FORT LEE, Va. (Feb. 26, 2013) -- Improving your cholesterol levels is an important way to increase your heart's health as it reduces the chance for developing plaques in your cardiovascular system.
Plaques comprised of oxidized LDL cholesterol and macrophages (a type of white blood cell) can build within your arteries and block the passage of oxygen-rich blood, leading to damage of the tissue beyond the occlusion.
Additionally, surfaces lining the arteries are more prone to damage at those places where plaques are built up and can rupture, leading to particles breaking off and moving through the arterial system to the point where they are too large to pass. This also causes damage to tissues beyond the blockage.
It is important for you to know your cholesterol levels, determined by a blood test that your medical provider would order, and whether the results show any need for change.
Lifestyle changes -- improvements to diet and physical activity -- are usually recommended as first-line treatment for elevated cholesterol and/or triglyceride levels.
One of the most important things to change in your diet if you find that your cholesterol levels are not in the healthy range (green in the accompanying) is to improve the quality of fats in your diet.
Fat has a number of important roles in the body, which is why it is recommended that a portion of your daily calories come from fat. However, saturated and trans fats are what contribute to the formation of LDL cholesterol, the "bad" kind that is responsible for the formation of plaques in the cardiovascular system. It is important to know how to substitute healthier fats for those that contribute to risk for disease.
The Therapeutic Lifestyle Changes Diet, which was developed by the National Cholesterol Education Program of the National Institutes of Health, recommends that 25-35 percent of your daily calories come from fat and that less than 7 percent of your daily calories come from saturated fat. Saturated fats are solid at room temperature, and come largely from animal foods (though there are a few saturated fats that are from plant sources, such as coconut and palm kernel oils).
Marbling in beef, the fat between muscles in pork, the fat under the skin in poultry as well as the fat in dairy products are all sources of saturated fat. Generally, you can improve the leanness of your meat choices by selecting cuts with "loin" or "round" in the cut name.
Trans fats are solid, plant-based fats that occur through hydrogenation of oils, and should be minimized in the diet as much as possible because they not only raise LDL cholesterol but also lower HDL cholesterol (the good kind, which if above 60 mg/dl, has a cardioprotective effect). Trans fats are found in solid shortenings and some margarine products, as well as commercially prepared foods made with these products. You can identify trans fats in your packaged food choices when you see "hydrogenated" or "partially hydrogenated" in the ingredient list that is usually found just below the Nutrition Facts label.
Lowering the amount of saturated and trans fats consumed daily should be accompanied by an increase in intake of unsaturated fats. There are two kinds, monounsaturated and polyunsaturated, and both can help to lower LDL cholesterol levels when fat calories in the diet come from these sources rather than saturated and trans fats. Particularly good sources of monounsaturated fats are olives/olive oil, canola oil, peanuts/peanut oil, sunflower oil, avocado, and many nuts and seeds.
Polyunsaturated fats are important in the diet also, since they are the source for essential fatty acids (the body needs them but cannot formulate them from other constituents within the body). Polyunsaturated fats are found in many common cooking oils, as well as nuts and seeds.
Omega 3 fatty acids are one type of polyunsaturated fat and are important to heart health due to their anti-inflammatory effect as well as helping to manage blood pressure and prevent clotting. You can find omega 3 fatty acids in fatty fish such as salmon, mackerel, halibut, tuna (white albacore has more than chunk light), sardines and herring. Plant-based omega 3 fatty acid sources include walnuts, flax seed, broccoli and leafy greens among others.
While dietary cholesterol's influence on blood cholesterol levels has been debated in recent years, it is still important to remain conscious of how much you are regularly consuming. Current recommendations are for healthy individuals to limit their daily intake to 300 mg, while those with or at risk for heart disease should limit intake to 200 mg daily.
Dietary cholesterol is found in animal foods, and usually in sources high in saturated fat, so paying attention to foods high in saturated fat also helps in paying attention to cholesterol intake. However, eggs and shellfish are the exception, being relatively low in saturated fat content but high in cholesterol.
Now you know the importance of the kinds of fats in your diet and how to optimize them for your heart's health. Next week, we will look at soy, soluble fiber and plant stanols/sterols and their beneficial effects on your cholesterol level.