Dietary supplementation with trans-11- and trans-12-18 : 1 increases cis-9, trans-11-conjugated linoleic acid in human immune cells, but without effects on biomarkers of immune function and inflammation.
Trans-fatty acid intake is associated with an increased risk of CHD and diabetes. The effects of single trans-fatty acid isomers are largely unexplored. The present study examined the effects of a 6-week supplementation with two trans-18 : 1 isomers (trans-11 and trans-12) in human subjects on immune cells, several inflammatory and immunological biomarkers (for example, IL, TNFalpha, C-reactive protein, adiponectin, intercellular adhesion molecule-1, prostacyclin, phagocytic process). Following a 2-week adaptation period without supplements, the test group (n 12) received vaccenic acid (trans-11-18:1) and trans-12-18 : 1 in equal amounts (6.0 g/d) for 6 weeks. The control group (n 12) consumed an oil without trans-fatty acids and conjugated linoleic acids (CLA). Samples were collected at the end of both periods. Trans-11- and trans-12-18 : 1 were significantly increased in cellular lipids. The endogenous synthesis of cis-9, trans-11-CLA from trans-11-18 : 1 was demonstrated via increased CLA in cellular lipids of the test group. Generally, trans-isomer supplementation did not affect either inflammatory biomarkers (for example, IL-6, IL-8, TNFalpha) or immune function (for example, phagocytosis) during the present study. The dietary supplementation of trans-11- and trans-12-18 : 1 (6 g/d) and their accumulation in leucocytes had no effects on biomarkers of inflammation and immune function. However, because of the limited data on the safety of trans-fatty acid intake and effects of individual trans isomers on human health (for example, trans-9-18 : 1, trans-10-18 : 1) at present, it is prudent to reduce trans-fat intake in general.
Kuhnt
Katrin
K
Institute of Nutrition, Friedrich Schiller University, Dornburger Strasse 24, D-07743 Jena, Germany.
Kraft
Jana
J
Vogelsang
Heinz
H
Eder
Klaus
K
Kratzsch
Jürgen
J
Jahreis
Gerhard
G
D015121:6-Ketoprostaglandin F1 alpha / Q000097:blood; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001824:Body Constitution; D002097:C-Reactive Protein / Q000378:metabolism; D016207:Cytokines / Q000097:blood; D019587:Dietary Supplements / Q000009:adverse effects; D005260:Female; D006098:Granulocytes / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D007249:Inflammation / Q000097:blood* / Q000139:chemically induced; D007962:Leukocytes / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000096:biosynthesis / Q000097:blood*; D008055:Lipids / Q000097:blood; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects; D044242:Trans Fatty Acids / Q000009:adverse effects / Q000097:blood / Q000494:pharmacology*; D014166:Transferases / Q000097:blood
D015415:Biomarkers; D016207:Cytokines; D044243:Linoleic Acids, Conjugated; D008055:Lipids; D044242:Trans Fatty Acids; C503589:cis-9, trans-11-conjugated linoleic acid; D015121:6-Ketoprostaglandin F1 alpha; D002097:C-Reactive Protein; D014166:Transferases; D009584:Nitrogen