VITAMIN-E SUPPLEMENTATION COUNTERACTS THE FISH OIL-INDUCED INCREASE OF BLOOD-GLUCOSE IN HUMANS

The objective of the study was to examine the effect of extra vitamin E in fish oil. on some variables of glucose and lipid metabolism and o n fibrinolysis in mildly hypertriglyceridemic men. Twelve subjects wer e given 30 mL/d of an ordinary fish oil (5.4 g eicosapentaenoic acid a nd 3.2 g docosahexaenoic acid) stabilized with vitamin E (1.5 IU/g, FO ) and the same fish oil supplemented with extra vitamin E (4.5 IU/g, F O+E) for 4 wk in a randomized double-blind cross-over study. Fasting b lood glucose concentration was increased after the period on FO (by 10 %, P < 0.05), but was not changed after FO+E. Serum insulin was not si gnificantly changed after the period on FO, but it tended to increase after FO+E. Fasting insulin/glucose ratio was not changed after FO, bu t was significantly increased after FO+E (P < 0.05), indicating a more adequate pancreatic insulin response to glucose after FO+E. Serum tri glycerides decreased during the period on FO and FO+E (by 43%, P < 0.0 01, and 41%, P < 0.001, respectively) and plasma lipoprotein (a) [Lp(a )] concentrations in five individuals with high Lp(a) levels (>270 mg/ L) also decreased (by 22%, P < 0.05, and 16%, NS, respectively), with no significant differences between treatments. Plasminogen activator i nhibitor-1 activity and antigen were significantly increased after bot h treatments. It is concluded that extra vitamin E counteracts the blo od glucose increase that is often seen after fish oil intake.