Flaxseed lignan lowers blood cholesterol and decreases liver disease risk factors in moderately hypercholesterolemic men

The effects of flaxseed lignan (secoisolariciresinol diglucoside [SDG]) intake on hypercholesterolemia and liver disease risk factors in moderately hypercholesterolemic men were investigated. In a previous study, we reported that SDG attenuates high-fat, diet-induced hypercholesterolemia in mice. Here, we report a double-blinded, randomized, and placebo-controlled study in moderately hypercholesterolemic men in which we investigated the hypothesis that oral administration of SDG (20 or 100 mg) would decrease the level of blood cholesterol and liver disease risk factors induced by hypercholesterolemia in humans. Thirty men with total cholesterol levels of 4.65 to 6.21 mmol/L (180-240 mg/dL) were randomly assigned to 3 groups; 2 groups received flaxseed lignan capsules (SDG, 20 or 100 mg/d) and the other received placebo capsules for 12 weeks. We found that, compared to the subjects who received placebo, those who received 100 mg of SDG exhibited a significant reduction in the ratio of low-density lipoprotein/high-density lipoprotein cholesterol at baseline (P < .05) and at week 12 (P < .05). In addition, in SDG-treated subjects, we also observed a significant percentage decrease in the levels of glutamic pyruvic transaminase and γ–glutamyl transpeptidase relative to the levels at baseline (P < .01) and a significant percentage decrease in the level of γ–glutamyl transpeptidase relative to the placebo-treated group (P < .05). These results suggest that daily administration of 100 mg SDG can be effective at reducing blood level of cholesterol and hepatic diseases risk in moderately hypercholesterolemic men.