Effect of high doses of shark liver oil supplementation on T cell polarization and peripheral blood polymorphonuclear cell function

Fish oils supplementation has been recently widely used in prevention and treatment of the diseases in humans. Fish oil beneficial effects have been investigated in a number of animal disease models as well as human studies. Here, we examined clinical, immunological and biochemical effects of shark liver oil supplementation in high doses in 13 volunteers. The experiment was based on the consumption of 3.6 g of squalene, 3.6 g of alkylglycerols and 750 mg of n-3 polyunsaturated fatty acids (PUFA) per day for 4 weeks. We have shown the increased response of neutrophils towards bacteria, the increased level of C4 component of complement in blood, the rise of total antioxidant status of serum, and the predominance of Type I cytokine IFN-gamma, TNF-alpha and IL-2 production by peripheral blood mononuclear cells after shark liver oil intake. Moreover, shark liver oil supplementation markedly affect lipid metabolism and cholesterol balance. The increase of total cholesterol level from 182.92 +/- 29.290 mg/dl before oil consumption to 224.46 +/- 62.198 mg/dl after diet rich in oil, and the decrease of HDL fraction were noted. However, metabolism of lipids normalised spontaneously after the end of the experiment in all the individuals. The results of the present study have shown, that the main effects of shark liver oil are the result of the biological activity of squalene and 1-O-alkylglycerols, which dominate in the composition of the oil quantitatively. On the contrary, anti-inflammatory effects of n-3 PUFA do not manifest, when taking together with high doses of squalene and alkylglycerols. On the bases of these observations, we propose that shark liver oil supplementation in high doses is beneficial in bacterial, viral and fungal infections, whereas patients with atherosclerosis or autoimmune diseases should avoid the consumption of high amounts of shark liver oil.