Lignan Content of the Flaxseed Influences Its Biological Effects in Healthy Men and Women

Abstract

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.