Effect of Animal and Industrial Trans Fatty Acids on HDL and LDL Cholesterol Levels in Humans - A Quantitative Review

• Published in: PloS one Vol. 5; no. 3; p. e9434
• Main Authors: Brouwer, I.A, Wanders, A.J, Katan, M.B
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 02.03.2010; Public Library of Science (PLoS)
• Subjects: Animals; biohydrogenation; blood; Blood cholesterol; Cardiovascular disease; Cardiovascular diseases; Chemical properties; Cholesterol; Cholesterol, HDL - metabolism; Cholesterol, LDL - metabolism; Comparative analysis; conjugated linoleic acid; Coronary artery disease; coronary disease; Coronary Disease - metabolism; Coronary heart disease; cows; Diet; energy; Fatty acids; Feeds; Health risks; healthy-human subjects; Heart; Heart diseases; High density lipoprotein; high density lipoprotein cholesterol; Humans; hydrogenated soybean oil; Hydrogenation; insulin sensitivity; linear models; Linoleic acid; Linoleic Acids, Conjugated - metabolism; Lipoproteins; Lipoproteins (high density); Lipoproteins (low density); Lipoproteins - blood; Lists; Low density lipoprotein; low density lipoprotein cholesterol; Low density lipoproteins; middle-aged men; moderately hyperlipidemic subjects; Monounsaturated fatty acids; Nutrition; plasma-lipids; Public Health and Epidemiology; Public Health and Epidemiology/Social and Behavioral Determinants of Health; Randomized Controlled Trials as Topic; Regression Analysis; Reviews; Risk; Rumen; serum-lipoproteins; Sheep; Trans fatty acids; Trans Fatty Acids - metabolism; Vegetable oils; United States > US; Netherlands
• DOI: 10.1371/journal.pone.0009434
• ISSN: 1932-6203

Trans fatty acids are produced either by industrial hydrogenation or by biohydrogenation in the rumens of cows and sheep. Industrial trans fatty acids lower HDL cholesterol, raise LDL cholesterol, and increase the risk of coronary heart disease. The effects of conjugated linoleic acid and trans fatty acids from ruminant animals are less clear. We reviewed the literature, estimated the effects trans fatty acids from ruminant sources and of conjugated trans linoleic acid (CLA) on blood lipoproteins, and compared these with industrial trans fatty acids. We searched Medline and scanned reference lists for intervention trials that reported effects of industrial trans fatty acids, ruminant trans fatty acids or conjugated linoleic acid on LDL and HDL cholesterol in humans. The 39 studies that met our criteria provided results of 29 treatments with industrial trans fatty acids, 6 with ruminant trans fatty acids and 17 with CLA. Control treatments differed between studies; to enable comparison between studies we recalculated for each study what the effect of trans fatty acids on lipoprotein would be if they isocalorically replaced cis mono unsaturated fatty acids. In linear regression analysis the plasma LDL to HDL cholesterol ratio increased by 0.055 (95%CI 0.044-0.066) for each % of dietary energy from industrial trans fatty acids replacing cis monounsaturated fatty acids The increase in the LDL to HDL ratio for each % of energy was 0.038 (95%CI 0.012-0.065) for ruminant trans fatty acids, and 0.043 (95% CI 0.012-0.074) for conjugated linoleic acid (p = 0.99 for difference between CLA and industrial trans fatty acids; p = 0.37 for ruminant versus industrial trans fatty acids). Published data suggest that all fatty acids with a double bond in the trans configuration raise the ratio of plasma LDL to HDL cholesterol.