Fats: Value and Danger of Various Food Components
Government guidelines say that we should consume no more than 30 percent of total daily calories as fat. Actually, optimal fat intake may be much lower, perhaps 15 to 20 percent, or even less. To reverse coronary heart disease, Dr. Dean Ornish cuts fat to a mere 10 percent of total calories, and cholesterol to 5 mg. Most recently, concern has been raised from research that such an extremely low-fat diet may increase triglycerides and lower HDL, which would actually have the effect of increasing heart disease risk for some individuals. This contrasts with the American Heart Association's recommendation of 30 percent of total calories as fat and 300 mg of cholesterol.
Besides increasing the risk of cardiovascular disease, a high-fat diet also increases the risk of cancer, obesity, and diverticulitis, which is an inflammation of the colon due to pockets of stagnant digested matter.
There are three kinds of dietary fats: saturated, polyunsaturated, and monounsaturated.
Saturated fats are primarily found in animal foods and in tropical oils, such as coconut and palm oil, which are solid at room temperature. These fats can be the most harmful, because they easily clog arteries.
Polyunsaturated fats are found in safflower, sunflower, corn, and fish oils. They contain both omega-6 and omega-3 essential fatty acids (EFAs). Theoretically, humans evolved on a diet that consisted of small and approximately equal amounts of omega-6 and omega-3 fatty acids, but now most people eat about twenty times more omega-6 than omega-3.
Omega-6 is useful in repairing injuries and causing blood to clot and blood vessels to constrict. Omega-3, however, inhibits blood clotting, relaxes smooth muscles in blood vessel walls, and protects against heart arrhythmias, thereby reducing the risk of heart disease. Many foods are rich in omega-3 EFAs, including cold-water fish, such as salmon and mackerel, and flax and flaxseed oil. Smaller amounts of omega-3 fatty acids are contained in great northern, navy, kidney, and soybeans. Among oils, flaxseed oil and canola oil are high in omega-3 EFAs, and so are soy, pumpkin seed, evening primrose, borage seed, walnut, and black currant oils. Actually, the best source of omega-3 fatty acids is flaxseed oil. It contains 50 percent omega-3, compared to the 10 percent found in canola oil.
With the discovery of the relationship between cholesterol and heart disease, Americans were encouraged to switch from animal fats, such as butter, to polyunsaturated fats, including the oils we just discussed. Unfortunately, this solution presented another set of problems. When these oils undergo metabolism, they are highly susceptible to lipid peroxidation, or rancidity, which gives rise to harmful free radicals. Most researchers now believe that it is better to use monounsaturated fats, which not only reduce the risk of lipid peroxidation but also reduce LDL, or bad cholesterol, while maintaining high levels of HDL, or good cholesterol. Olive oil and canola oil are high in monounsaturated fats.
Margarine is a polyunsaturated oil that has undergone hydrogenation to make it solid at room temperature. However, hydrogenation creates man-made molecules called trans-fatty acids, which may interfere with metabolic functions. Thus, in the rush away from butter, many people may have ended up compromising their health.
Nonetheless, very recently, some researchers concluded that monounsaturated fats may not be any better than polyunsaturated fats, because monounsaturated fats may be only slightly less susceptible to oxidation than polyunsaturated fats.
Therefore, when all these complexities are weighed and sorted, the bottom-line recommendation: Cut back on all forms of fats, except omega-3!
BEST ALTERNATIVE MEDICINE: WHAT WORKS? WHAT DOES NOT? by Dr. Kenneth R.
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Dr. Kenneth R. Pelletier. All Rights Reserved.