title: Effect of royal jelly ingestion for six months on healthy volunteers.
abstract: BACKGROUND
  Royal jelly is a widely ingested supplement for health, but its effects on humans are not well known. The objective was to evaluate the effects of long-term royal jelly ingestion on humans.
  
  
  METHODS
  We conducted a randomized placebo-controlled, double-blind trial. A total of 61 healthy volunteers aged 42-83 years were enrolled and were randomly divided into a royal jelly group (n = 31) and a control group (n = 30). Three thousand mg of royal jelly (RJ) or a placebo in 100 ml liquid/day were ingested for 6 months. The primary outcomes were changes in anthropometric measurements and biochemical indexes from baseline to 6 months after intervention.
  
  
  RESULTS
  Thirty subjects in the RJ group and 26 in the control group were included in the analysis of endpoints. In an adjusted mean change of the variables from the baseline, significant differences between the two groups could be found in red blood cell counts (+0.16x10⁶/μL for the RJ group vs. -0.01x10⁶/μL for the control group, P = 0.0134), hematocrit (+0.9% vs. -0.8%, P = 0.0251), log (fasting plasma glucose) (+0.01 ± 0.01 log mg/dL vs. +0.05 ± 0.01 log mg/dL, P = 0.0297), log (insulinogenic index) (+0.25 vs. -0.13, P = 0.0319), log dehydroepiandrosterone sulfate (DHEA-S) (+0.08 log μg/dL vs. +0.20 log μg/dL, P = 0.0483), log testosterone (T) (+0.12 ± 0.04 log ng/mL vs. -0.02 ± 0.05 log ng/mL, P = 0.0416), log T/DHEA-S ratio (+0.05 ± 0.05 vs. -0.23 ± 0.59, P = 0.0015), and in one of the SF-36 subscale scores, mental health (MH) (+4 vs. -7, P = 0.0276).
  
  
  CONCLUSIONS
  Six-month ingestion of RJ in humans improved erythropoiesis, glucose tolerance and mental health. Acceleration of conversion from DHEA-S to T by RJ may have been observed among these favorable effects.
authors.affiliation: Department of General Internal Medicine, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan. hmorita@gifu-u.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Morita
authors.forename: Takahide
authors.initials: T
authors.lastname: Ikeda
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kajita
authors.forename: Kei
authors.initials: K
authors.lastname: Fujioka
authors.forename: Ichiro
authors.initials: I
authors.lastname: Mori
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Okada
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Uno
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Ishizuka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000735:Androstenedione / Q000097:blood / Q000378:metabolism; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood / Q000378:metabolism; D019587:Dietary Supplements; D004311:Double-Blind Method; D004920:Erythropoiesis; D005227:Fatty Acids / Q000008:administration & dosage*; D005260:Female; D006397:Hematinics / Q000008:administration & dosage*; D006801:Humans; D007333:Insulin Resistance; D057194:Intention to Treat Analysis; D007564:Japan; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D013997:Time Factors; D000099219:Royal Jelly
chemical_list: D000735:Androstenedione; D019314:Dehydroepiandrosterone Sulfate; D005227:Fatty Acids; D006397:Hematinics; D000099219:Royal Jelly