Flaxseed supplementation improved insulin resistance in obese glucose intolerant people: a randomized crossover design

Yeong Rhee,Ardith Brunt

doi:10.1186/1475-2891-10-44

Abstract

BackgroundObesity 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.MethodsUsing 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-α, and IL-6), glucose, insulin, and thiobaribituric acid reactive substance (TBARS) were measured before and after of each supplementation.ResultsFlaxseed 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).ConclusionsThe 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.

Highlights

IntroductionThis study determined antioxidant activity of flaxseed and its role in inflammation and insulin resistance in obese glucose intolerant people
Obesity leads to an increase in inflammation and insulin resistance
In conclusion, it was hypothesized that an antioxidant in flaxseed would decrease reactive oxygen species (ROS) generation which downregulates tumor necrosis factor (TNF)-a and IL-6 production

Summary

Introduction

This study determined antioxidant activity of flaxseed and its role in inflammation and insulin resistance in obese glucose intolerant people. Studies have reported that pro-inflammatory cytokines, tumor necrosis factor (TNF)-a and interleukin (IL)-6, are associated with an increased hepatic C-reactive protein (CRP) synthesis, inflammation, and insulin resistance in humans and animals [5,6,7,8,9,10,11,12,13,14]. The active ingredient of flaxseed (lignan, secoisolariciresinol diglucoside (SDG)) has significant antioxidant effects by inhibiting DNA scissions and lipid peroxidation and decreaseing ROS [18,19,20,21]. Dietary flaxseed, flaxseed oil, or flaxseed lignan decreased inflammation, oxidative lung damages, lipid peroxidation, or hyperinsulinemia in animals [24,31,32,33]

Methods

Results

Discussion

Conclusion