getpdf

Changes in Tissue Fatty Acid Composition Due to a Fat Free Diet

Ivančica Delaš1*, Milivoj Popović1 and Frane Delaš2


1
School of Medicine, University of Zagreb, Department of Chemistry and Biochemistry, Šalata 3, HR – 10 000 Zagreb, Croatia

2Faculty of Food Technology and Biotechnology, University of Zagreb, Laboratory of Microbiology, Pierottijeva 6, HR – 10 000 Zagreb, Croatia

Article history:

Received March 17, 1999
Accepted June 14, 1999

Key words:

fat free diet, essential fatty acid, brain, heart, liver, erythrocyte, rat

Summary:

Linoleic (C18:2, n-6) and linolenic (C18:3, n-3) acids cannot be synthesized in the organism and are therefore essential components of the diet. Fat free diets (FFD), which contain less than 1 % of total energy content as fats, are used as therapy in some gastrointestinal diseases and lipid metabolism disorders. Because of the lack of the essential fatty acids (EFA), fat free diets can induce symptoms of essential fatty acids deficiency. In this study, we have investigated changes in fatty acid composition of total lipids of brain, heart and liver, as well as of erythrocyte membranes, induced by FFD fed to rats for two weeks. Control and FFD were isoenergetic, with the lipid portion substituted by carbohydrates. The most pronounced differences were found in liver tissue, while in other tissues modifications were of a lesser degree, but still evident. As a consequence of a FFD, total lipids contained less linoleic acid, as well as other long chain polyunsaturated fatty acids (arachidonic, C20:4,n-6; eicosapentaenoic, C20:5,n-3; docosahexaenoic, C22:6,n-3), with the consecutive increase of endogenously synthesized monoenoic acids (palmitoleic, C16:1,n-9 and oleic, C18:1,n-9). In this way, requested ratio of saturated to unsaturated fatty acids is preserved, what is of special importance for the composition of phospholipids, responsible for the structure and function of cell membranes. The results express the ability of cells to compensate the lack of EFA in the diet by endogenous synthesis, »tendering« the effect of insufficient ingestion of fats and EFA, respectively.



*Corresponding author:          This email address is being protected from spambots. You need JavaScript enabled to view it.
                                               ++385 1 45 66 753
                                               ++385 1 45 90 206