title: Current issues surrounding the definition of trans-fatty acids: implications for health, industry and food labels.
abstract: The definition of trans-fatty acids (TFA) was established by the Codex Alimentarius to guide nutritional and legislative regulations to reduce TFA consumption. Currently, conjugated linoleic acid (CLA) is excluded from the TFA definition based on evidence (primarily preclinical studies) implying health benefits on weight management and cancer prevention. While the efficacy of CLA supplements remains inconsistent in randomised clinical trials, evidence has emerged to associate supplemental CLA with negative health outcomes, including increased subclinical inflammation and oxidative stress (particularly at high doses). This has resulted in concerns regarding the correctness of excluding CLA from the TFA definition. Here we review recent clinical and preclinical literature on health implications of CLA and ruminant TFA, and highlight several issues surrounding the current Codex definition of TFA and how it may influence interpretation for public health. We find that CLA derived from ruminant foods differ from commercial CLA supplements in their isomer composition/distribution, consumption level and bioactivity. We conclude that health concerns associated with the use of supplemental CLA do not repudiate the exclusion of all forms of CLA from the Codex TFA definition, particularly when using the definition for food-related purposes. Given the emerging differential bioactivity of TFA from industrial v. ruminant sources, we advocate that regional nutrition guidelines/policies should focus on eliminating industrial forms of trans-fat from processed foods as opposed to all TFA per se.
authors.affiliation: Metabolic and Cardiovascular Diseases Laboratory, Molecular Cell Biology of Lipids Group, Alberta Diabetes and Mazankowski Alberta Heart Institutes, 4-002J Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, AB, Canada T6G 2E1.
authors.forename: Ye
authors.initials: Y
authors.lastname: Wang
authors.forename: Spencer D
authors.initials: SD
authors.lastname: Proctor
mesh_terms: D000818:Animals; D002318:Cardiovascular Diseases / Q000517:prevention & control; D002986:Clinical Trials as Topic; D004041:Dietary Fats; D019587:Dietary Supplements; D019649:Food Industry / Q000592:standards*; D005515:Food Labeling / Q000592:standards*; D006304:Health Status; D006801:Humans; D044243:Linoleic Acids, Conjugated / Q000032:analysis; D009369:Neoplasms / Q000517:prevention & control; D018673:Nutrition Policy; D009765:Obesity / Q000517:prevention & control; D012418:Ruminants; D044242:Trans Fatty Acids / Q000009:adverse effects* / Q000032:analysis*
chemical_list: D004041:Dietary Fats; D044243:Linoleic Acids, Conjugated; D044242:Trans Fatty Acids