Dr. Clif CleavelandEarlier this month, the Food and Drug Administration took timid, preliminary steps to eliminate most trans-fatty acids (TFAs) from the nation’s food supply. Abundant medical evidence points to TFAs as a significant factor in coronary heart disease. While the FDA dithers, consumers should avoid TFAs.
Some occur naturally in very small amounts in dairy products and meat, but the majority in the American diet result from the use of hydrogenated vegetable oils.
In the early 1900s, chemists perfected a technique to convert liquid vegetable oils, composed of what’s known as cis-fatty acids, into a semi-solid form that was easier to store and transport. Technically known as partially hydrogenated fat, or trans fats, it significantly increased shelf life and, by mid-century, partially hydrogenated vegetable oils had become popular as margarines and in products such as Crisco and other semi-solid cooking oils. Incorporation of TFAs in baked goods assured a tasty product with a longer expiration date.
Trans fats replaced lard and beef tallow in frying as concerns rose that consumption of saturated animal fats contributed to America’s increasing incidence of heart disease. Trans fats showed up increasingly in packaged snack foods, baked goods, cookies, crackers, chips and doughnuts. At peak usage in the 1990s, trans fat contributed up 2 to 3 percent of the average daily caloric intake of adults.
Increasing evidence accumulated in the scientific literature that that TFAs were harmful to human health. They led an increase in low density lipoproteins (“bad cholesterol”) and a decrease in high density lipoproteins (“good cholesterol”). Levels of triglycerides, another fat carried in the blood, increased.