Hydrogenated oils are often used in frying and processed food products as a cheap replacement for butter. In these oils, which are sold as margarine and shortening, the essential fatty acids have been chemically converted to an oil that has both a higher melting point and a longer shelf-life. Though originally promoted as a healthier alternative to conventional oils, research since the 1990s has indicated that consumption of hydrogenated oils increases the risk of coronary heart disease, heart attack, and stroke.
Structure of Hydrogenated Oils
The hydrogenation process adds hydrogen atoms to fatty acids. Trans-fatty acids occur when hydrogen atoms are located on opposite sides of two double-bonded carbon atoms. Cis-fatty acids occur when hydrogen atoms are on the same sides. Trans-fatty acids are solid at room temperature. Cis-fatty acids are liquid at room temperature. Natural foods have more cis-fatty acids than trans-fatty acids, although a small amount of trans-fatty acids are found in some animal products.
Trans-Fats Effects on Blood Lipid Levels
As reported in the New England Journal of Medicine in 1999, consumption of trans-fats has adverse effects on blood lipid levels. Hydrogenated fats raise cholesterol levels. Trans-fatty acids, similar to saturated fats, increase low-density lipoprotein or LDL cholesterol, the "bad" cholesterol, to a significant degree. However, unlike saturated fats, trans-fatty acids also decrease the levels of high-density lipoprotein, HDL, or "good" cholesterol levels. The net effect of trans-fatty acids on increasing the ratio of LDL to HDL is approximately double that of saturated fatty acids. In addition, trans-fatty acids increase Lp(a) lipoprotein levels, another risk factor for increased risk of heart disease and stroke.
Increased Risk of Heart Attack and Stroke
Low-density lipoprotein (LDL) transports cholesterol throughout your body. When LDL levels are elevated, cholesterol builds up in arterial walls, making them hard and narrow. When this occurs in coronary arteries, the arteries that supply the heart with blood, coronary artery disease develops. Furthermore, when the build-up of fatty deposits, or plaques, tear or rupture, a blood clot can form. Blood clots can block the flow of blood to the heart, causing a heart attack. If the clot stops blood flow to the brain, it will cause a stroke.
Increased Risk of Heart Disease
The New England Journal of Medicine reported in 1999 that an absolute increase of only two percent in the intake of trans fatty acids results in a 53 percent increase in the risk of coronary heart disease. In addition, the increase in Lp(a) lipoprotein levels caused by trans-fatty acids are also associated with increased risk of coronary heart disease.
Increased Triglyceride Levels
Trans-fatty acids raise triglyceride levels to a small degree. Triglycerides come from fats eaten in foods and, if not immediately used for energy, are stored by the body in fat cells. Although small, the effect of the increase in triglyceride levels with the consumption of fatty acids could further increase your risk of cardiovascular disease.
Member Comments