Clinical and metabolic response to flaxseed oil omega-3 fatty acids supplementation in patients with diabetic foot ulcer: A randomized, double-blind, placebo-controlled trial.

BACKGROUND

Data on the effects of flaxseed oil omega-3 fatty acids supplementation on wound healing and metabolic status in subjects with diabetic foot ulcer (DFU) are scarce.

OBJECTIVE

This study was conducted to evaluate the effects of flaxseed oil omega-3 fatty acids supplementation on wound healing and metabolic status in subjects with DFU.

METHODS

The current randomized, double-blind, placebo-controlled trial was conducted among 60 subjects (aged 40-85years old) with grade 3 DFU. Subjects were randomly allocated into two groups (30 subjects each group) to receive either 1000mg omega-3 fatty acids from flaxseed oil supplements or placebo twice a day for 12weeks.

RESULTS

After the 12-week intervention, compared with the placebo, omega-3 fatty acids supplementation resulted in significant decreases in ulcer length (-2.0±2.3 vs. -1.0±1.1cm, P=0.03), width (-1.8±1.7 vs. -1.0±1.0cm, P=0.02) and depth (-0.8±0.6 vs. -0.5±0.5cm, P=0.01). Additionally, significant reductions in serum insulin concentrations (-4.4±5.5 vs. +1.4±8.3 μIU/mL, P=0.002), homeostasis model of assessment-estimated insulin resistance (-2.1±3.0 vs. +1.0±5.0, P=0.005) and HbA1c (-0.9±1.5 vs. -0.1±0.4%, P=0.01), and a significant rise in the quantitative insulin sensitivity check index (+0.01±0.01 vs. -0.005±0.02, P=0.002) were seen following supplementation with omega-3 fatty acids compared with the placebo. In addition, omega-3 fatty acids supplementation significantly decreased serum high sensitivity C-reactive protein (hs-CRP) (-25.5±31.5 vs. -8.2±18.9μg/mL, P=0.01), and significantly increased plasma total antioxidant capacity (TAC) (+83.5±111.7 vs. -73.4±195.5mmol/L, P<0.001) and glutathione (GSH) concentrations (+60.7±140.2 vs. -15.5±129.7μmol/L, P=0.03) compared with the placebo.

CONCLUSIONS

Overall, omega-3 fatty acids supplementation for 12weeks among subjects with DFU had beneficial effects on parameters of ulcer size, markers of insulin metabolism, serum hs-CRP, plasma TAC and GSH levels. In addition, flaxseed oil omega-3 fatty acids may have played an indirect role in wound healing due to its effects on improved metabolic profiles.