Kinetics of the incorporation of dietary fatty acids into serum cholesteryl esters, erythrocyte membranes, and adipose tissue: an 18-month controlled study

Abstract

Tissue levels of 11-3 Fatty acids reflect dietar) intake, but quantitative data ahout rate of incorporation and levels as a function of intake are scarce.We fed 58 men 0, 3, 6, or 9 g / d of fish oil for 12 months arid monitored fatty acids i l l serum cholesteryl esters, erythrocytes, and siibciitaneoiis Fat during and after supplementation.Eicosapentaenoic acid (EPA) in cholesteryl esters plateaued after 4-8 weeks; the incorporation half-life was 4.8 days.Steady-state levels increased by 3.9 i 0.3 mass % points (i SE) for each extra gram of EPA eaten per day.Incorporation of docosahexaenoic acid (DHA) was erratic; plateau valiies were 1.1 i 0.1 mass 'ib higher for evety g / d ingested.Incorporation of EPA into erythrocyte membranes showed a half-life of28 days; a steady state was reached after 180 days.Each g/d increased levels by 2.1 i 0.1 inass %.C22:5n-3 levels increased niarkedly.(:hanges in DHA were erratic and smaller.EPA levels in adipose tissue rose also; the change after 6 months was 67% of that after 12 months in gluteal and 75% in abdominal Lit.After 12 months each grarn per day caused an 0.11 +-0.01 mass % rise in gluteal fat for EPA, 0.53 2 0.07 for C22:5n-3, and 0.14 2 0.03 for DH.4.uThus, different (11-3) fatty acids were incorporated with different efficiencies, possihly because of interconversions or different affinities of the eniymatic pathways involved.EPA levels in cholesteryl esters reflect intake over the past week or two, erythrocytes over the past month or two, and adipose tissue over ;I period of years.These findings may help in assessing the intake of (n-3) fatty acids in epidemiological studies.-Katan,M. B., J. P. Deslypere, A. P. J. M. van Birgelen, M. Penders, and M. Z e p w d .Kinetics of the incorporation of dietar?, 11-3 fatty acids into serum cholesteryl esters, erythrocyte menibranes, and adipose Abhrc\iatioiis: I.(A'l., Iecithit~:rtiolesterol a( hutylatetl hydroxytoluene (:!,ti-di-tert-hutyl-p-c pentaenoic acid; DHA, docosahexaenoic acid; ; i i i i i r i r tetraacetate; LDL, low density lipoprotein.\Joint lirst authors.(;en t.Belgi ti in.