Objective: The omega-3 polyunsaturated fatty acid (n-3 PUFA) as well as lignan components of flaxseed (FLX) can have beneficial effects. In this 6-week-long, randomized, double-blinded, placebo-controlled study, we investigated the effects of FLX lignans on cardiovascular risk factors.
Methods: Thirty-seven subjects (13 men and 24 women, age: 54±7 years, body mass index [BMI]: 29.7±1 kg/m2) consumed nutrition bars with similar macronutrient contents. The fatty acid composition and the lignan contents of the bars differed significantly. Two FLX bars both contained 3.0 g of alpha linolenic acid (ALA: 18:3 n-3) but different amount of lignans (0.15 g vs. 0.41 g).
Results: High-lignan FLX decreased total cholesterol (C) by 12% (p=0.044), LDL-C by 15% (p=0.022), and oxidized (Ox)-LDL by 25% (p=0.035). Regular FLX tended to increase Ox-LDL by 13% (p=0.051). The difference between the effects of high-lignan vs. regular lignan FLX on Ox-LDL was highly significant (p=0.004).
Conclusion: High-lignan FLX has the unique property of decreasing Ox-LDL, which is an independent risk factor for cardiovascular disease.