Dietary levels of trans-fatty acids: basis for health concerns and industry efforts to limit use

Dietary trans-fatty acids at sufficiently high levels have been found to increase low-density lipoprotein cholesterol and decrease high-density lipoprotein cholesterol compared with diets high in cis monounsaturated or polyunsaturated fatty acids. The dietary levels of trans-fatty acids necessary to do this appear to be approximately 4% of energy or higher to increase low-density lipoprotein cholesterol and approximately 5% to 6% of energy or higher to decrease high-density lipoprotein cholesterol, compared with control diets essentially trans-free. In response, the food industry is working on ways to eliminate or greatly reduce trans-fatty acids in food products. Current efforts focus on 4 technological options: (1) modification of the hydrogenation process, (2) use of interesterification, (3) use of fractions high in solids from natural oils, and (4) use of trait-enhanced oils. Challenges to the food industry in replacing trans-fatty acids in foods are to develop formulation options that provide equivalent functionality, are economically feasible, do not greatly increase saturated fatty acid content, and meet the regulatory deadline of January 1, 2006.