Effects of omega-3 fatty acids and vitamin C administration on lipoproteins, apo A-I and apo B in hyperlipidemia

Introducation: The control of hyperlipidemia is vital in CVD patients. Omega-3 fatty acids (O3FAs) have desirable effects on serum triglycerides (TG), thrombosis and arrhytharrythmia but lead to an increase in serum LDL and apo B as well. Vitamin C can induce LDL receptor activity of the liver and catabolize LDL particles. To determine the effects of adminstration of O3FAs, Vitamin C, and O3FAs+ vitamin C on serum levels of LDL, apo B, other serum lipids and compare these effects, the present study was performed at the Tehran University of Medical Sciences from 2000 to 2001. In a double-blind, placebo controlled trial with parallel design, 68 hyperlipidemic patients [total cholestrol (TC) and triglycerides (TG) greater than 200 mg/dL] were randomly assigned to receive daily 500 mg vitamin C, 1g O3FAs, 500 mg vitamin C + 1 g O3FAs or placebo (control) for 10 weeks. Fasting blood samples were collected at the beginning and at the end of this period. TG, TC, LDL, HDL were enzymatically, vitamin C calorimetrically, apo B and apo A-I immunoturbidometrically measured. For statistical analysis, ANOVA, paired t test, Chi square and repeated measurement ANOVA were used. There were no significant changes during the study in pattern of food consumption, socioeconomic and anthropometric indices. There was a significant increase in the blood vitamin C level at the end of the study, in comparison to the initial value in vitamin C (p=0.001) and vitamin C + O3FAs (p=0.02) groups. There was a significant difference in the serum TC (p=0.004), apo B (p=0.005) and decrease in apo A-I/apo B (p=0.05) at the end of the study in comparion to the initial values as well as a significant increase in blood vitamin C compared to the control group (p=0.01). At the end of the study in O3FAs group, the TG/HDL and apo B respectively had significant decreases as compared to the beginning (p=0.04, p=0.05, respectively) and TG/HDL of this group at the end of the study significant decereased compared to the control group (p=0.04). There was no significant difference in HDL, LDL, apo A-I and LDL/HDL during the study in each group. Simultaneous administration of O3FAs and vitamin C had no beneficial effect on the lipid profile of hyperlipidemic patients, but 1 g purified O3FAs daily for 10 weeks is a beneficial supplement for decreasing TG and TG/HDL without any increase in LDL and apo B. 500 mg vitamin C for more than 10 weeks possibly decreases TC and apo B significantly in hyperlipidemic patients as compared to the control group.