Efficacy and safety of Citrus sudachi peel in obese adults: A randomized, double-blind, pilot study

Authors

  • Masashi Akaike Department of Medical Education, The University of Tokushima, Graduate School of Medical Sciences, Kuramoto-cho, Tokushima 770-8503
  • Ken-ichi Aihara Department of Medicine and Bioregulatroy Sciences, The University of Tokushima, Graduate School of Medical Sciences, Kuramoto-cho, Tokushima 770-8503
  • Hiroaki Yanagawa Clinical Trial Center for Developmental Therapeutics, Tokushima University Hospital, Kuramoto-cho, Tokushima 770-8503
  • Takashi Iwase Department of Cardiovascular Medicine, Tokushima University Hospital, Kuramoto-cho, Tokushima 770-8503
  • Sumiko Yoshida Department of Medicine and Bioregulatroy Sciences, Tokushima University Hospital, Kuramoto-cho, Tokushima 770-8503
  • Chiho Sato Clinical Trial Center for Developmental Therapeutics, Tokushima University Hospital, Kuramoto-cho, Tokushima 770-8503
  • Tomoka Saijo Clinical Trial Center for Developmental Therapeutics, Tokushima University Hospital, 3-18-15, Kuramoto-cho, Tokushima 770-8503
  • Hiroaki Mikasa Support Center for Medical Education, School of Medicine, The University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima 770-8503
  • Yoshizaki Kashiwada Department of Natural Medicines, The University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima 770-8503
  • Yoshihisa Takaishi Department of Natural Medicines, The University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima 770-8503
  • Koichiro Tsuchiya Department of Medical Pharmacology, The University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima 770-8503
  • Toshiaki Tamaki Department of Pharmacology, The University of Tokushima, Graduate School of Medical Sciences, 3-18-15, Kuramoto-cho, Tokushima 770-8503
  • Toshio Matsumoto Department of Medicine and Bioregulatroy Sciences, The University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima 770-8503
  • Masataka Sata Department of Cardiovascular Medicine, The University of Tokushima, Graduate School of Medical Sciences, 3-18-15, Kuramoto-cho, Tokushima 770-8503

DOI:

https://doi.org/10.31989/ffhd.v4i7.5

Abstract

Objective: This study was undertaken to explore the efficacy and safety of Citrus sudachi peel for metabolic risk factors in obese male and female adults.

Background: Citrus sudachi Hort. ex Shirai (Rutaceae), called “sudachi”, is a small, round, green citrus fruit that is mainly cultivated in Tokushima Prefecture in Japan. Our group reported that Citrus sudachi peel powder improved glucose tolerance and dyslipidemia in Zucher-fatty rats and reduced hyperglycemia and hypertriglyceridemia in GK diabetic rats.

Materials and Methods: We conducted a randomized, double-blind, placebo-controlled trial in 40 participants with abdominal obesity and metabolic risk factors including hypertension, impaired glucose tolerance and elevated triglyceride levels. Participants were randomized to receive either tablets that contained 1.3 g dried Citrus sudachi peel powder or placebo tablets for 12 weeks. The sudachi peel group included 14 males and 5 females with a mean age of 54.5 years, and the placebo group included 18 males and 2 females with a mean age of 51.9 years. 

Results: Physical status including body weight, waist circumference and blood pressure and laboratory markers including metabolic parameters were not different at any observation point between the two groups. However, among participants with serum triglyceride levels of more than 120 mg/dl, body weight, waist circumference and serum triglyceride levels were significantly decreased at several observation points after the start of treatment in the sudachi peel group but not in the placebo group. No serious adverse events were observed in the sudachi peel group. 

Conclusions: Citrus sudachi peel has the potential effect to safely improve abdominal obesity and lower serum levels of TG in obese individuals with hypertriglyceridemia. A large-scale randomized, double-blind clinical study targeting subjects with both abdominal obesity and high TG levels is needed to confirm the metabolic effects of Citrus sudachi peel.

Trial registration: UMIN Clinical Trials Registry (UMIN-CTR) UMIN000002682.  Accession number of the Ethics Committee for Clinical Trials of Food in Tokushima University Hospital is F5.

Key words: health functional food, anti-obesity, triglyceride

Published

2014-07-24

Issue

Section

Research Articles