Abstract
Although the reduction of serum triacylglycerol concentrations by dietary fish oil is a well-known effect, the exact mechanism of this effect has not been previously studied in human subjects. Therefore, the aim of this study was (i) to examine the effect of short-term fish oil supplementation on blood concentrations of ketone bodies, free fatty acids and triacylglycerol in healthy humans and (ii) to verify whether the observed relationships between these variables would be consistent with reduced lipolysis and/or enhanced hepatic fatty acid oxidation after fish oil supplementation. Twenty subjects (21–23 years, normal liver function tests) were randomly divided into two groups to supplement their usual diet with either 30 g/d of fish oil (n=11) or olive oil (n=9). Venous blood samples were drawn after an overnight fast, before and after 1, 3 and 7 d of fish oil/olive oil supplementation. Blood concentrations of triacylglycerol and free fatty acids decreased consistently after fish oil supplementation; the reduction was already significant after one day of fish oil (P<0.001 for triacylglycerol andP=0.01 for free fatty acids). In contrast, neither of these blood values changed after olive oil supplementation (P>0.10). No significant changes in glucose, insulin or ketone body levels were observed in either group after supplementation. After fish oil, but not after olive oil supplementation, the ratio of blood ketone body levels to free fatty acid levels increased significantly (P<0.05). Furthermore, after fish oil supplementation only, free fatty acid levels were significantly correlated with levels of ketone bodies (day 7 of supplementation: r=0.90,P<0.001) and triacylglycerol (maximum value on day 3: r=0.77,P<0.01). These findings suggest that reduced lipolysis and increased hepatic β-oxidation/ketogenesis may contribute to reduced triacylglycerol levels after ω3 fatty acid supplementation in humans. Turnover studies are needed in order to further quantitate these processes.
Similar content being viewed by others
Abbreviations
- CPT:
-
carnitine palmitoyl transferase
- DHA:
-
docosahexaenoic acid
- EPA:
-
eicosapentaenoic acid
- VLDL:
-
very low density lipoprotein(s)
References
Simopoulos, A.P. (1991)Am. J. Clin. Nutr. 54, 438–463.
Harris, W.S. (1989)J. Lipid Res. 30, 785–807.
Harris, W.S., Rothrock, D.W., Fanning, A., Inkeles, S.B., Goodnight, S.H., Illingworth, D.R., and Connor, W.E. (1990)Am. J. Clin. Nutr. 51, 399–406.
Stacpoole, P.W., Alig, J., Ammon, L., and Crockett, S.E. (1989)Metabolism 38, 946–956.
DeLany, J.P., Vivian, V.M., Snook, J.T., and Anderson, P.A. (1990)Am. J. Clin. Nutr. 52, 477–485.
Nozaki, S., Garg, A., Lena Vega, G., and Grundy, S.M. (1991)Am. J. Clin. Nutr. 53, 638–642.
Annuzzi, G., Rivellese, A., Capaldo, B., Di Marino, L., Iovine, C., Marotta, G., and Riccardi, G. (1991)Atherosclerosis 87, 65–73.
Nestel, P.J., Conner, W.E., Reardon, M.F., Connor, S., Wong, S., and Boston, R. (1984)J. Clin. Invest. 74, 82–89.
Lang, C.A., and Davis, R.A. (1990)J. Lipid Res. 31, 2079–2086.
Wong, S.-H., and Marsh, J.B. (1987)Metabolism 37, 1171–1181.
Halminski, M.A., Marsh, J.B., and Harrison, E.H. (1991)J. Nutr. 121, 1554–1561.
Rustan, A.C., Nossen, J.O., Christiansen, E.N., and Drevon, C.A., (1988)J. Lipid Res. 29, 1417–1426.
Benner, K.G., Sasaki, A., Gowen, D.R., Weaver, A., and Connor, W.E. (1990)Lipids 25, 534–540.
Parks, J.S., Johnson, F.L., Wilson, M.D., and Rudel, L.L. (1990)J. Lipid Res. 31, 455–466.
Yeo, Y.K., and Holub, B.J. (1990)Lipids 25, 811–814.
Lottenberg, A.M.P., Oliveira, H.C.F., Nakandakare, E.R., and Quintao, E.C.R. (1992)Lipids 27, 326–330.
Singer, P., Wirth, M., and Berger, I. (1990)Atherosclerosis 83, 167–175.
Otto, D.A., Baltzell, J.K., and Wooten, J.T. (1992)Lipids 27, 1013–1017.
Mellanby, T., and Williamson, D.H. (1974) inMethods of Enzymatic Analysis (Bergmeyer, H.O., ed.) Vol. 4, 2nd edn., pp. 1840–1843. Verlag Chemie, Weinheim/Academic Press, New York.
Williamson, D.H., and Mellanby, T. (1974) inMethods of Enzymatic Analysis (Bergmeyer, H.O., ed.) Vol. 4, 2nd edn., pp. 1836–1839. Verlag Chemie, Weinheim/Academic Press, New York.
Armitage, P., and Berry, G. (1987)Statistical Methods in Medical Research, 2nd edn., Blackwell, Oxford.
Schluchter, M.D. (1990) inBMDP Statistical Software Manual, Vol. 2, (Dixon, W.J., ed.) pp. 1207–1244, University of California Press, Berkeley.
Rustan, A.C., and Drevon, C.A. (1989)J. Internal Med. 225 (Suppl. 1), 31–38.
Zhang, Z.J., Wilcox, H.G., Elam, M.B., Castellani, L.W., and Heimberg, M. (1991)Lipids 26, 504–511.
Wong, S.H., Nestel, P.J., Trimble, R.P., Storer, G.B., Illman, R.J., and Topping, D.L. (1984)Biochim. Biophys. Acta 729, 103–109.
Bergseth, S., Christiansen, E.N., and Bremer, J. (1986)Lipids 21, 508–514.
Illman, R.J., Trimble, R.P., Storer, G.B., Topping, D.L., and Oliver, J.R. (1986)Atherosclerosis 59, 313–321.
Marsh, J.B., Topping, D.L., and Nestel, P.J. (1987)Biochim. Biophys. Acta 922, 239–243.
Topping, D.L., Trimble, R.P., and Storer, G.B. (1987)Biochim. Biophys. Acta 927, 423–428.
Brady, P.S., Marine, K.A., Brady, L.J., and Ramsay, R.R. (1989)Biochem. J. 260, 93–100.
Surette, M.E., Whelan, J., Broughton, K.S., and Kinsella, J.E. (1992)Biochim. Biophys. Acta 1126, 199–205.
Drevon, C.A., Hustvedt, B.-E., and Rustan, A.C. (1992) Program and Abstracts of theThird International Congress on Essential Fatty Acids and Eicosanoids. Adelaide, Australia, p. 46.
Rich, A.J. (1990)Proc. Nutr. Soc. 49, 361–373.
Williamson, D.H. (1971)Postgrad. Med. J. 47, (Suppl.) 371–375.
Havel, R.J., Kane, J.P., Balasse, E.O., Segel, N., and Basso, L.V. (1970)J. Clin. Invest. 49, 2017–2035.
McGarry, J.D., and Foster, D.W. (1977)Arch. Intern. Med. 137, 495–501.
Author information
Authors and Affiliations
About this article
Cite this article
Dagnelie, P.C., Rietveld, T., Swart, G.R. et al. Effect of dietary fish oil on blood levels of free fatty acids, ketone bodies and triacylglycerol in humans. Lipids 29, 41–45 (1994). https://doi.org/10.1007/BF02537089
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02537089