, Volume 13, Issue 1, pp 35–43 | Cite as

Effect of licorice flavonoid oil on visceral fat in obese subjects in the United States

A randomized, double-blind, placebo-controlled study
  • Yuji Tominaga
  • Mitsuaki Kitano
  • Tatsumasa Mae
  • Sachie Kakimoto
  • Kaku NakagawaEmail author
Original Research


Abdominal obesity, or accumulation of visceral fat, is mainly associated with the onset of metabolic syndrome. Licorice flavonoid oil (LFO) consisting of licorice hydrophobic polyphenols in mediumchain triglycerides (MCT) is a new functional food ingredient effective in preventing metabolic syndrome. We have demonstrated significant effects of LFO on reduction of total body fat and visceral fat together with body weight in overweight Japanese subjects. Obesity is a more serious problem in Western countries such as Europe and the United States compared to Japan. We hypothesized that LFO could also work for abdominally obese people in Western countries. We therefore tested the effects of 300 mg LFO concentrate solution taken once daily with evening meals for up to 12 weeks in obese adult male and female subjects in the United States. Results showed that visceral fat, as measured by an abdominal CT scan, waist circumference measurements and waist-to-hip ratio significantly decreased in subjects in the LFO group compared to the placebo group at Week 12. The side-effect profile of LFO was indistinguishable from placebo. Moreover, no adverse trends or toxicologically meaningful differences in haematology and chemistry test results, vital signs or physical examinations were observed that were attributable to LFO. These results indicate that LFO is a safe food ingredient for preventing metabolic syndrome not only in Japan but also in Western countries such as Europe and the United States.


licorice flavonoid Glycyrrhiza glabra L. metabolic syndrome visceral fat, total body fat abdominal fat 



licorice flavonoid oil


medium-chain triglycerides


adverse event


body mass index


basal metabolic rate


computed tomography


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Copyright information

© CEC editore - Springer-Verlag Italia 2014

Authors and Affiliations

  • Yuji Tominaga
    • 1
  • Mitsuaki Kitano
    • 1
  • Tatsumasa Mae
    • 2
  • Sachie Kakimoto
    • 2
  • Kaku Nakagawa
    • 2
    Email author
  1. 1.Pharmacology & Toxicology Laboratory Frontier Biochemical and Medical Research LaboratoriesKaneka CorporationHyogoJapan
  2. 2.QOL DivisionKaneka CorporationOsakaJapan

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