The grapeseed oil was enriched in conjugated 10t,12c C18:2 linoleic and lit C18:1 vaccenic acids by alk. hydrolysis and acidification with following cryst. from urea. The sheep milk fat was enriched in 9c,11t C18:2 linoleic and lit C18:1 oleic acids and the fish (mackerel) oil was enriched in C20:5 eicosapentaneoic and C22:6 docosahexaneoic acids by similar methods. All 3 prepns. were combined to produce a bioactive lipid complex (BKL). The supplementation of feeding dose for rats fed with a diet rich in saturated fatty acids (pork lard) with BKL resulted in a significant decrease in all atherogenic indices of blood (triglycerides by 32%, total cholesterol by 27% and lipoprotein by 28%). The decrease was significantly higher as compared to those for particular lipid BKL components because of their synergistic activity.