The effects of licorice flavonoid oil with respect to increasing muscle mass: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: The present study evaluated the effects of licorice flavonoid oil (LFO) with respect to increasing the muscle mass of elderly populations using a randomized, double-blind, placebo-controlled study. Fifty participants aged 54-90 years (seven men, 43 women), who underwent rehabilitation treatment for osteoarthritis of the knee, were examined and assigned to either the LFO group (n = 26) or the placebo group (n = 24). The LFO group consumed 300 mg LFO day-1 , whereas the placebo group consumed one placebo capsule every day for 16 weeks. We measured muscle mass, body fat percentage and the Japanese Knee Osteoarthritis Measure score at baseline and every 4 weeks thereafter.

RESULTS: In the LFO group, muscle mass in the body trunk increased significantly after 16 weeks of LFO intake (+0.38 kg, P = 0.02). The trunk muscle mass weight of the LFO group increased significantly compared to that of the placebo group (P < 0.01). Furthermore, the body fat percentage and body trunk fat percentage of the LFO group were significantly suppressed compared to that of the placebo group (P = 0.03 and P < 0.01, respectively).

CONCLUSION: The results of the present trial indicate that LFO supplementation has effects with respect to increasing muscle mass and suppressing the body fat percentage of elderly populations, especially in the body trunk. © 2016 Society of Chemical Industry.