Capparis spinosa L. (Caper) fruit extract in treatment of type 2 diabetic patients: a randomized double-blind placebo-controlled clinical trial

Complement Ther Med. 2013 Oct;21(5):447-52. doi: 10.1016/j.ctim.2013.07.003. Epub 2013 Aug 7.


Objectives: Capparis spinosa L. (Caper) fruit is traditionally used as an anti-hyperglycemic food by Iranian diabetic patients. But yet, no controlled human study has determined its efficacy in treatment of hyperglycemia in type 2 diabetic patients.

Design: The present study was undertaken to explore the possible anti-hyperglycemic effects of the caper fruit extract in type 2 diabetic patients. A randomized clinical trial was conducted in 54 type 2 diabetic patients. Two groups 28 and 26 patients on standard anti-diabetic therapy, received 400mg caper fruit extract and placebo capsules three times a day respectively for two months.

Main outcome measures: The patients fasting blood glucose, glycosylated hemoglobin, lipids levels, liver and renal function tests were determined at baseline and endpoint.

Results: Results showed significant decrease in fasting blood glucose levels (p=0.037) and glycosylated hemoglobin (p=0.043) in caper treated patients compared to control group at the end of the study. Triglyceride level also decreased significantly (p=0.29) in caper treated group at the end of the study compared to baseline. No liver, kidney and other side effects were observed in these two groups.

Conclusions: Caper fruit extract may be a safe anti-hyperglycemic and anti-hypertriglyceridemic agent for type 2 diabetic patients.

Keywords: Capparis spinosa; Clinical trial; Diabetes; Medicinal plants.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Glucose / drug effects
  • Capparis / chemistry*
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Diabetes Mellitus, Type 2 / physiopathology
  • Double-Blind Method
  • Female
  • Fruit / chemistry*
  • Glycated Hemoglobin / metabolism
  • Humans
  • Iran
  • Kidney Function Tests
  • Lipids / blood
  • Liver Function Tests
  • Male
  • Middle Aged
  • Placebos
  • Plant Extracts / chemistry
  • Plant Extracts / therapeutic use*
  • Treatment Outcome


  • Blood Glucose
  • Glycated Hemoglobin A
  • Lipids
  • Placebos
  • Plant Extracts
  • hemoglobin A1c protein, human