Licorice flavonoid oil reduces oxidative stress and total body fat in overweight subjects: a randomized, double-blind, placebo-controlled study

In this study with 30 nurses as study subjects, we examined how 12 weeks of a study treatment affected body measurements, blood biochemistry, and the oxidative stress regulatory system. Subjects were randomly divided into two groups: one that received licorice flavonoid oil (LFO) capsules and L-carnitine capsules (supplement group n = 15), and another that received placebo capsules (placebo group n = 15), for 12 consecutive weeks. Measurements of oxidative stresses and other tests were performed at baseline and after 4, 8, and 12 weeks of treatment. Results showed that only the supplement group showed a significant decrease in waist circumference at 8 weeks when compared to baseline, while neither group showed a change in body mass index. No changes in blood biochemistry were observed in either group. Only the supplement group showed a significant decrease in oxidative stresses at 8 weeks when compared to baseline, while the placebo group did not show any change. Both groups showed a significant decrease in anti-oxidant potential, but at 12 weeks the supplement group showed a significantly higher level than the placebo group. While the supplement group showed a stable BAP to d-ROM ratio (representing latent anti-oxidant potential), the placebo group had a significant decrease. These results demonstrate that 12 weeks of LFO and L-carnitine consumption decreases waist circumference and oxidative stresses and maintains latent anti-oxidant potential.