Key Findings:
Secoisolariciresinol diglucoside (SDG) is an antioxidant that can prevent DNA scissions and lipid peroxidation as well as decrease radical oxidation species (ROS). On this research, flaxseed supplementation reduced insulin resistance. The HOMA-IR index significantly decreased, suggesting a decrease in insulin resistance or decreased glucose concentration following flaxseed supplementation. TBARS concentrations were also reduced and signal a decline in lipid peroxidation. TNF-a, IL-6, and CRP remained within normal ranges which indicates that the obese participants did not have low grade systemic inflammation. CRP in contrast was elevated following the heat bran (control) diet. Since these participants did not have an identified inflammatory condition, flaxseed supplementation may have not affected these inflammation biomarkers.
ABSTRACT:
Obesity leads to an increase in inflammation and insulin resistance. This study determined antioxidant activity of flaxseed and its role in inflammation and insulin resistance in obese glucose intolerant people. Using a randomized crossover design, nine obese glucose intolerant people consumed 40 g ground flaxseed or 40 g wheat bran daily for 12 weeks with a 4-week washout period. Plasma inflammation biomarkers (CRP, TNF-a, and IL-6), glucose, insulin, and thiobaribituric acid reactive substance (TBARS) were measured before and after of each supplementation. Flaxseed supplementation decreased TBARS (p = 0.0215) and HOMA-IR (p = 0.0382). Flaxseed or wheat bran supplementation did not change plasma inflammatory biomarkers. A positive relationship was found between TBARS and HOMA-IR (r = 0.62, p = 0.0003). The results of the study weakly support that decreased insulin resistance might have been secondary to antioxidant activity of flaxseed. However, the mechanism(s) of decreased insulin resistance by flaxseed should be further determined using flaxseed lignan. (Author’s abstract)