Influence of a cod liver oil diet in healthy and insulin-dependent diabetic volunteers on fatty acid pattern, inhibition of prostacyclin formation by low density lipoprotein (LDL) and platelet thromboxane

Abstract

Ten healthy and twenty diabetic volunteers (type 1) received 15 capsules (à 450 mg) cod liver oil for 2 weeks daily in addition to a "normal" diet. The levels of eicosapentaenoic acid in the plasma phospholipids of both groups were increased after the treatment. The inhibition of the prostacyclin formation by LDL was diminished when the LDL was isolated after the treatment in comparison to LDL taken in the same concentration and from the same donors before it. The thromboxane B2 (TXB2) synthesis capacity of clotting whole blood, thrombin-induced TXB2 formation by platelets as well as the 15(S)-hydroxy-11 alpha,9 alpha-epoxymethano-5Z, 13E-prostadienoic acid-induced platelet aggregation were not altered by the treatment in healthy volunteers, whereas in diabetics the TXB2 formation capacity of clotting whole blood was decreased after the treatment in comparison with before it.

Fish Oil–Induced Changes in Apolipoproteins in IDDM Subjects

“…This is despite numerous studies in which fish oil supplementation has been examined in both non-insulin-dependent diabetic (NIDDM; [10][11][12][13] and IDDM subjects (14)(15)(16)(17). The most consistent Serum lipids in patients without retinopathy (A; n = 10) and with retinopathy (B; n = 6) during baseline, after 3 wk treatment with Max EPA, and 6 wk after ceasing Max EPA.…”

“…However, when a greater quantity of w3FA was used, there was a decrease in total cholesterol (12). Small quantities of co3FA (<1 g EPA/day) had no effect on cholesterol and lipoproteins in both NIDDM and IDDM subjects (13)(14)(15).…”

“…Changes in apolipoproteins have not, with the exception of apoB, been described (4,11,18,20). Results from studies in which fish oils have been given to diabetic subjects are somewhat varied (10)(11)(12)(13)(14)(15)(16)(17). In patients with NIDDM consuming 12 g/day Max EPA for 4 wk, the levels of total cholesterol and LDL-chol were unaffected, although apoB was increased (11).…”

n-3 Fatty Acids in the Treatment of Diabetic Patients

“…Blood pressure and vascular compliance Blood pressure was unaltered in several studies of type 1 diabetic patients (83,84,86) and only decreased in one controlled study (90). Also in patients with type 2 diabetes, blood pressure was largely unaltered by supplementation with n-3 fatty acids (104).…”

“…In patients with type 1 diabetes, dietary n-3 fatty acids decrease platelet reactivity (83)(84)(85)(86)(87)(88), without changing plasma fibrinogen levels (89 -92) or other coagulation parameters (84,92,93). One study in type 1 diabetic subjects showed increased levels of type 1 plasminogen activator inhibitor (PAI-1) (an endogenous inhibitor of fibrinolysis) after supplementation with n-3 fatty acids (92).…”