TRANS FAT IS A MAJOR HEALTH HAZARD IN THE USA AND EVERYWHERE ELSE

Your Health: Trans Fat a Major Health Hazard in American Diet Rallie McAllister, M.D., M.P.H.

Like it or not, New York City restaurant patrons soon will be eating less trans fat when they dine out. On Dec. 5, 2006, New York City's Board of Health adopted a resolution to restrict the service of food products containing artificial trans fat at New York City restaurants. While the political and economic implications of the resolution have been hotly debated, there's little doubt that consumption of trans fat has negative health consequences. In clinical studies, trans fats have been shown to elevate total blood cholesterol and levels of low-density lipoprotein (LDL) cholesterol. Even worse, they tend to reduce levels of heart-healthy high-density lipoprotein (HDL) cholesterol. No other known dietary component has both of these adverse effects, each of which contributes to the development of heart disease, a condition shared by more than 12 million Americans. Each year, heart disease claims the lives of more than 500,000 people in the United States. There's also evidence to suggest that consumption of trans fat can trigger insulin resistance, boosting the risk of developing type 2 diabetes. In the body, trans fat may interfere with the normal metabolism of essential fatty acids, leading to disruptions in the production of various hormones and blood clotting factors. Most of the trans fat in the typical American diet is artificially created in a process known as hydrogenation, in which plant oils are exposed to hydrogen in the presence of a catalyst at high temperatures. The process changes the structure of the chemical bonds in fat, transforming them from a liquid to solid state. With their revised chemical structure, hydrogenated oils don't break down or become rancid as quickly as naturally occurring oils and fats. This property comes in handy in the preparation of fried foods, including chicken, donuts, and French fries. It also helps retard spoilage and prolong the shelf-life of commercially prepared baked goods, including cakes, pies, cookies, and crackers. Not all trans fat in the U.S. diet is artificially engineered: Small amounts occur naturally in grazing animals used in food production. While trans fat may contribute as much as half of the total fat content in commercially prepared foods, it typically comprises just 2 to 6 percent of the total fat content of beef and dairy products. The chemical structure of trans fat in animal products is different than the structure of artificially produced trans fat. At this point, it isn't entirely clear if this difference makes them less of a hazard to human health. Regardless of the source, health and nutrition experts agree that Americans consume too much of the bad fat. According to data published by the U.S. Food and Drug Administration, the average daily intake among adults is about 5.8 grams. Guidelines issued by the American Heart Association recommend that trans fat consumption be kept below one percent of total energy intake. The Institutes of Medicine concluded that because trans fat confers no known health benefit and contributes to heart disease, intake should be as low as possible. One way to reduce your consumption of trans fat is to avoid eating commercially prepared fried foods. Choosing a bagel instead of a donut for breakfast will eliminate about 5 grams of trans fat from your diet, and foregoing the French fries at lunch will cut out another 8 grams. While you're reducing your consumption of fried fare, you can also choose pre-packaged foods that are free of trans fat. Since January 2006, the FDA has required food manufacturers to list trans fat content on the Nutrition Facts panels of all food items and many nutritional supplements. When you're preparing food at home, it's a good idea to use ingredients that contain monounsaturated and polyunsaturated fats. Unlike trans fat, monounsaturated and polyunsaturated fats do not elevate blood cholesterol levels, and both offer a number of health benefits when consumed in moderation. Polyunsaturated fats are found in plant oils, including sunflower, safflower, and sesame seed oil, as well as in some varieties of fish, including tuna and salmon. Canola oil and olive oil contain monounsaturated fats. To reduce your consumption of trans fat in animal products, choose fat-free or low-fat dairy products, and lean meats, including baked poultry without the skin, and the leanest cuts of beef and pork. It's not practical to completely eliminate all trans fat from your diet, but lowering your intake will go a long way toward reducing your risk of heart disease and improving your overall health.

Rallie McAllister, M.D., M.P.H., is a family physician in Kingsport, Tenn., and author of "Healthy Lunchbox: The Working Mom's Guide to Keeping You and Your Kids Trim." Her Web site is http://www.rallieonhealth.com. To find out more about Rallie McAllister, M.D., and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.

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