In a new study, the Centers for Disease Control (CDC) reports that trans fat blood levels among Americans declined 58 percent between 2000 and 2008 after the Food and Drug Administration (FDA) required food manufacturers to label their products with how much of the unhealthy ingredient they contain.
The decline was evident in blood drawn from a sample of Americans as part of the CDC’s once-every-decade National Health and Nutrition Examination Survey. The drop was unusually large and abrupt.
Our findings provide information about the effectiveness of these interventions,” said Hubert W. Vesper, the CDC chemist who conducted the analysis, in a comment to the Washington Post. “This reduction is substantial progress that should lower the risk of cardiovascular disease in the people.”
Trans fats increase the risk of heart disease by raising LDL cholesterol while lowering HDL levels. A 2009 study in the Annals of Internal Medicine points out, “Trans fat intake has a large effect on cardiovascular health: A mere 2 percent increase in energy intake from trans fat may increase the risk of a coronary event by up to 23 percent.” The CDC study, published in the Journal of the American Medical Association, shows population-wide levels of LDL have declined and HDL levels have increased since the FDA regulation took effect. While the labeling regulation is certainly part of this improvement, other dietary changes, increases in exercise and wider use of cholesterol-lowering statin drugs probably contributed as well.
In addition, after the FDA established its labeling rule, a number of states and local jurisdictions took their own regulatory initiatives. The most prominent was New York City’s 2006 decision to bar restaurant use of food containing “artificial” trans fats (those created in the manufacturing process, not those that occur naturally in some foods). California also banned trans fat in restaurant food (in 2010) and retail baked goods (2011). Many communities have adopted local bans as well.
Before the NYC ban, 50 percent of the city’s restaurants used trans fat oil. Two years later, 98 percent were using no trans fat.
Trans fat is the result of hydrogenation, a process through which hydrogen is added to liquid oils – peanut butter and margarine are common examples – to make them solid at room temperature. Invented in the early 20th century, hydrogenation allowed soy bean processors to convert the otherwise wasted soy oil by-product into margarine which, with the addition of food coloring, provided an attractive substitute for butter that was scarce and relatively expensive. In peanut butter, hydrogenation eliminated the necessity to remix the oil and solids prior to each use.
As early as the 1940s, research revealed a likely connection between trans fat and cancer but manufacturers resisted regulation by emphasizing margarine’s low cost and asserting that its lack of saturated fat made it healthier than butter (an assertion that turned out to be incorrect). Margarine use increased until the mid-1960s. Crisco (hydrogenated cottonseed oil) was also widely used in that era and is still in use today.
The connection between trans fat and heart disease was suggested by research in the late 1950s but was not strongly pursued. Only in the 1990s was the link fully confirmed, opening the door to the successful regulatory initiatives of the past decade.