Thursday, January 19, 2006

Margarine

Margarine is a golden yellow solid spread that has been touted for many decades as a healthier alternative to butter. It is manufactured of polyunsaturated vegetable oils that are altered chemically by saturating their carbon bonds with hydrogen. Hydrogenation changes the liquid vegetable oils to a solid. As a result, it can be used like butter on toast, rolls, and other foods. Hydrogenation also renders the oils more stable, so they are less perishable and have a longer shelf life.

The "margarine is healthy" campaign has been very effective in terms of sales. People who were concerned about their cholesterol levels and risk of heart attack abandoned butter and dramatically increased margarine use. In fact, by 1980, margarine consumption was almost triple that of butter. Hydrogenated and partially hydrogenated oils are ubiquitous, used in all types of fast food products and processed foods. These include crackers, snack foods, salad oils, cooking oils, bread , and pretty much everything else you eat.

Are the health claims made for margarine actually true? A number of studies have turned up troubling data on this subject. While it is true that margarine contains no cholesterol, the process of hydrogenation changes not only the physical form of the oils but alters the way they are metabolized by the body. Once vegetable oils are hydrogenated, they are no longer polyunsaturated. In fact, with hydrogenation, the beneficial structure of the essential fatty acids is altered or destroyed. As a result, the final margarine product is much lower in essential fatty acids. Most of the beneficial oils have been changed to a form called transfatty acids. These transfatty acids tend to predominate in margarine, with some samples containing as much as 60 percent of their oils in this altered form.

Transfatty acids behave differently than the natural oils from which they were derived. They burn more slowly than natural oils and interfere with their function. Transfatty acids also tend to concentrate in the heart. Ominously, recent studies show that people eating four or more teaspoons per day of margarine actually have a significantly increased risk of cardiovascular disease. In one study reported in the New England Journal of Medicine, the trans-fatty acids in margarine were found to increase LDL cholesterol. This is the type of cholesterol associated with an increased risk of heart attacks. Transfatty acids were also found to lower the beneficial and protective HDL cholesterol levels. Other studies have shown that transfatty acids also increase the level of triglycerides, another risk factor for cardiovascular disease.

Another drawback of margarine is that its high water content continues to alter its chemical structure while it is on the supermarket shelf. This degrades the product further. What is the solution? Ideally, people in our society should decrease their intake, both margarine and butter. With 40 percent of the average American diet composed of fats, intake of margarine should be sharply curtailed. For those who want to continue to use fats in food preparation, the amount should be decreased significantly. Steaming, roasting, broiling, and other preparation techniques that are fat free should be favored over frying and sautéing in large quantities of oil. When cooking with oil, often a small amount will work just as well. Instead of using margarine as a spread for toast, rolls, or other grain products, use fresh fruit preserves or raw seed and nut butters that have their natural oils intact. Try olive oil as a topping instead of margarine; it is delicious on bread and toast. Avoid fast food outlets since they tend to use partially hydrogenated oils in much of their food preparation. Also, read labels carefully when you buy convenience foods and processed foods in the supermarket. If they contain hydrogenated oil, you are better off buying a safer substitute that contains natural oil, or no oils.

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