Daily intake of Citrus jabara fruit peel powder (Japanese Patent No. 5,323,127) improves allergy-like symptoms: A randomized double-blind parallel-group comparative study

Abstract

Citrus jabara (CJ) is a rare citrus fruit that used to grow naturally only in the southern part of the Kii Peninsula in Japan. Human intervention studies with oral intake of CJ fruit have shown its anti-allergic effects, but the testing method was a pre-post comparison study. In this study, we conducted a randomized, double-blind, parallel-group interventional study to evaluate the volume-dependent effects of oral intake of CJ fruit peel powder (Japanese Patent No. 5,323,127) on nasal and eye allergy-like symptoms. Ninety healthy adults were allocated to three groups and given test foods containing 1,000, 500, and 0 mg of CJ peel powder, with one packet per day for 4 weeks. After excluding those who dropped out or deviated from the study protocol, 73 were included in the efficacy analysis and 86 in the safety analysis. The high-dose group (1,000 mg/day) was significantly lower than the placebo group in the scores of “nasal and eye symptoms” at week 4, and “blocked nose” at weeks 2 and 4 in the evaluation of question I of Japanese Rhino-conjunctivitis Quality of Life Questionnaire (JRQLQ No. 1). The changes in scores (difference from the pre-observation period) on the Nasal and Eye Symptom Questionnaire showed a dose-dependent reduction in rhinorrhea. In the safety evaluation, there were no significant differences in examinations of physiology, hematology, and blood biochemistry between the groups, and no adverse events attributable to the test foods were observed. These results suggest that intake of CJ peel powder can alleviate allergy-like symptoms.