title: Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial.
abstract: BACKGROUND
  Adverse effects of industrially produced trans fatty acids (iTFAs) on the risk of coronary artery disease are well documented in the scientific literature; however, effects of naturally occurring trans fatty acids (TFAs) from ruminant animals (rTFA), such as vaccenic acid (VA) and cis-9,trans-11 conjugated linoleic acid (c9,t11-CLA), are less clear. Although animal and cell studies suggest that VA and c9,t11-CLA may be hypocholesterolemic and antiatherogenic, epidemiologic data comparing rTFAs and iTFAs are inconsistent, and human intervention studies have been limited, underpowered, and not well controlled.
  
  
  OBJECTIVE
  We determined the effects of VA, c9,t11-CLA, and iTFA, in the context of highly controlled diets (24 d each), on lipoprotein risk factors compared with a control diet.
  
  
  RESULTS
  We conducted a double-blind, randomized, crossover feeding trial in 106 healthy adults [mean ± SD age: 47 ± 10.8 y; body mass index (in kg/m(2)): 28.5 ± 4.0; low-density lipoprotein (LDL) cholesterol: 3.24 ± 0.63 mmol/L]. Diets were designed to have stearic acid replaced with the following TFA isomers (percentage of energy): 0.1% mixed isomers of TFA (control), ∼3% VA, ∼3% iTFA, or 1% c9,t11-CLA. Total dietary fat (34% of energy) and other macronutrients were matched. Total cholesterol (TC), LDL cholesterol, triacylglycerol, lipoprotein(a), and apolipoprotein B were higher after VA than after iTFA; high-density lipoprotein (HDL) cholesterol and apolipoprotein AI also were higher after VA. Compared with control, VA and iTFA both increased TC, LDL cholesterol, ratio of TC to HDL cholesterol, and apolipoprotein B (2-6% change; P < 0.05); VA also increased HDL cholesterol, apolipoprotein AI, apolipoprotein B, and lipoprotein(a) (2-6% change; P < 0.05), whereas iTFA did not. c9,t11-CLA lowered triacylglycerol (P ≤ 0.01) and had no effect on other lipoprotein risk factors.
  
  
  CONCLUSIONS
  With respect to risk of cardiovascular disease, these results are consistent with current nutrition labeling guidelines, with the requirement of VA, but not c9,t11-CLA, to be listed under TFA on the Nutrition Facts Panel. This trial was registered at clinicaltrials.gov as NCT00942656.
authors.affiliation: USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD;
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Gebauer
authors.affiliation: Nestlé Research Center, Lausanne, Switzerland; and.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Destaillats
authors.affiliation: Nestlé Research Center, Lausanne, Switzerland; and.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Dionisi
authors.affiliation: Children's Hospital Oakland Research Institute, Oakland, CA.
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Krauss
authors.affiliation: USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD; david.baer@ars.usda.gov.
authors.forename: David J
authors.initials: DJ
authors.lastname: Baer
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology; D002784:Cholesterol / Q000819:agonists / Q000097:blood; D008078:Cholesterol, LDL / Q000819:agonists* / Q000097:blood; D018592:Cross-Over Studies; D004042:Dietary Fats, Unsaturated / Q000009:adverse effects*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006865:Hydrogenation; D006937:Hypercholesterolemia / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D015228:Hypertriglyceridemia / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D044243:Linoleic Acids, Conjugated / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009829:Oleic Acids / Q000009:adverse effects*; D010938:Plant Oils / Q000009:adverse effects* / Q000737:chemistry; D012307:Risk Factors; D044242:Trans Fatty Acids / Q000009:adverse effects*; D014280:Triglycerides / Q000819:agonists / Q000097:blood
chemical_list: D008078:Cholesterol, LDL; D004042:Dietary Fats, Unsaturated; D044243:Linoleic Acids, Conjugated; D009829:Oleic Acids; D010938:Plant Oils; D044242:Trans Fatty Acids; D014280:Triglycerides; C503589:cis-9, trans-11-conjugated linoleic acid; D002784:Cholesterol; C050413:11-octadecenoic acid
keywords: cardiovascular disease risk; industrial trans fatty acids; partially hydrogenated vegetable oil; ruminant trans fatty acids; vaccenic acid