Yeast Strain GNL24/497 Safety Evaluation and Efficacy Validation on the Discomfort of Knee in Healthy Adults - Placebo-controlled Double-blind Randomized Clinical Trial -

Noriko Zamoto, Fumi Nihei, Akira Kubo, Yoshiyuki Saito, Kazunaga Yazawa

Research output: Contribution to journalArticle


Objectives: The primary aim of this study was to analyze in detail the safety of the yeast strain GNL24/497. This was achieved by evaluating biochemical and physiological assay testing of the blood and urine after ingestion of 2500 mg/day (i.e. fivefold the daily dosage in healthy adults experiencing discomfort in the knee). To validate the effect on this discomfort after a 500 mg dose as previously reported for 4 weeks, our second aim was to evaluate whether the effect was altered when ingestion was maintained for 12 weeks. Methods: A placebo-controlled double-blind randomized clinical trial was conducted. Forty five healthy Japanese volunteers (range: 50-74 years old) were separated into three groups and each subjected to blood and urine testing once a month. To compare the yeast strain (500 mg per day) with the placebo for 12 weeks, Japanese Knee Osteoarthritis Measure (JKOM) and a 5 point scale questionnaire were used to evaluate 17 healthy Japanese adults once a month. Results The blood test and urinalysis results did not indicate any health hazard from ingestion of the yeast. The amount of change in VAS scores and the 5 point scale scores were significantly lower in the yeast group compared with the placebo group after 12 weeks ingestion (P<0.05). Conclusion It is suggested that oral intake of the yeast strain GNL24/497 is probably safe and effective in reducing discomfort in the knee in healthy adults. Specifically, it is indicated that the reported effects were maintained in the case of ingestion for a period of 12 weeks.

Original languageEnglish
Pages (from-to)1037-1052
Number of pages16
JournalJapanese Pharmacology and Therapeutics
Issue number7
Publication statusPublished - 2016



  • Discomfort
  • Japanese Knee Osteoarthritis Measure (JKOM)
  • Knee
  • Safety
  • Yeast

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)

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