Earlier 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.
These adverse changes were proportionate to TFA intake. Fortunately, the changes were reversed as trans fats were eliminated from diets.
But studies also suggest that TFAs interfere with the normal function of the endothelial cells, which line our arteries and veins, and can cause inflammation.
In 2003, the FDA required that TFAs be included on the nutritional labels of most commercially prepared foods. The Department of Agriculture advised limiting TFA consumption in its food pyramid. These moves led to widespread, voluntary reduction in TFAs in many foods shipped across state boundaries.
In a 2006 review in the New England Journal of Medicine, the authors concluded, "On a per calorie basis, trans fats appear to increase the risk of (coronary heart disease) more than any other macronutrient." That same year, New York City Board of Health passed a law banning TFAs in restaurants and bakeries.
In 2007, the American Public Health Association urged that all governments - federal, state, and local - ban the use of TFAs in restaurants. The Dietary Guidelines for Americans 2010 and the Institute of Medicine also advise reducing TFAs as low as possible.
An estimated 20,000 heart attacks could be prevented annually by strict limiting of TFA consumption.
Despite extensive medical evidence, some argue that medical recommendations and FDA regulations are intrusive on personal choices. We accept bans on dangerous pesticides such as DDT and heptachlor; we recognize the poisonous aspects of dioxin.
TFAs represent similar, silent threats to our health. When poisons in our food chain are recognized, our government has an obligation to identify them and to legislate for their removal.
Contact Clif Cleaveland at email@example.com.