Efficacy of Spearmint Tea in Relieving Osteoarthritis of the Knee

Human Clinical Trial to Investigate the Effects of High Rosmarinic Acid Spearmint Tea on Markers of Pain, Physical Function and Disease Activity in Osteoarthritis of the Knee

The purpose of this study is to investigate the benefits of daily consumption of a high rosmarinic acid spearmint tea, developed by the University of Guelph, on measures of pain, physical function and disease activity in osteoarthritis of the knee.

The investigators hypothesize that a spearmint tea high in rosmarinic acid is efficacious in mitigating the symptoms of osteoarthritis of the knee through its actions in reducing cartilage degradation, oxidative stress and inflammation.

Study Overview

• Status: Completed
• Conditions: Osteoarthritis of the Knee
• Intervention / Treatment: Other: Commercially spearmint tea; Other: High Rosmarinic Acid Spearmint Tea

Detailed Description

Healthy adults with a clinical diagnosis of osteoarthritis of the knee will be recruited and will undergo a brief phone screening interview, followed by a detailed in-person screening process, to determine study eligibility.

Eligible participants will be matched according to sex, baseline pain according to the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and duration of osteoarthritis. Participants will then be randomly assigned to receive either the investigative high rosmarinic acid spearmint tea or a comparable placebo mint tea.

During the 4-month treatment period, participants will consume two cups (300 mL in the morning and 300 mL in the evening) of either the high rosmarinic acid spearmint tea (approximately 300 mg rosmarinic acid per day) or the commercial spearmint tea (approximately 20 mg of rosmarinic acid per day) daily.

Data collection will occur at baseline (week 0), mid-treatment (week 8), post-treatment (week 16), and follow-up (week 20). Outcome measures include WOMAC and SF-36 scores, physical function (6-minute walk, stair climb task), inflammatory markers (serum C-reactive protein), and self-reported changes in pain medication use. In a sub-set of consenting participants deemed eligible by the study physician, a synovial fluid sample will be drawn from the knee for the analyses of cartilage degradation biomarkers (GAG, COMP, PGE2, NO) at baseline (week 0) and post-treatment (week 16).

• Study Type: Interventional
• Enrollment (Actual): 49
• Phase: Phase 4

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Guelph, Ontario, Canada, N1G 2W1
      • University of Guelph
    • Guelph, Ontario, Canada, N1G2W1
      • Human Nutraceutical Research Unit, University of Guelph

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Is at least 18 years or older
• Have been diagnosed by a health care professional with osteoarthritis of the knee
• Demonstrates a WOMAC pain score greater then 125 at time of study screening

Exclusion Criteria:

• Has any other systemic or rheumatic arthritis
• Has completed or is planning to undergo knee replacement surgery
• Has had a chemical, radiologic, or surgical synovectomy in any large joint within the previous 3 months
• Has any concomitant inflammatory processes such as infectious or rheumatic disease
• Has any gastrointestinal ulcers
• Has any clinically significant, uncontrolled cardiovascular, hepatic, renal, or any other medical condition that may interfere with the study
• Has any serious medication conditions such as recent (within the previous 6 months) heart attack, stroke, cancer and/or diabetes
• Has a recent history (within the previous 6 months) of a clinically significant psychiatric disorder other than mild depression
• Has a known allergy or hypersensitivity to mint or any other food allergies
• Smokes, drinks alcohol (>14 drinks per week) or participates in recreational drug use
• Has participated in a clinical trial involving an investigational or marketed drug within the previous 6 months
• Women who are pregnant or plan to become pregnant during the study period, women who have recently (within the previous 6 months) given birth, women who are currently lactating or have only recently (within the previous 6 months) stopped lactating.

Study Plan

How is the study designed?

Design Details

• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo Control; Participants will consume two cups of commercial spearmint tea per day (300 mL in the morning and 300 mL in the evening, providing a total of approximately 20 mg of rosmarinic acid per day) for a total of 4 months.	Other: Commercially spearmint tea; Commercially available, non-selectively bred spearmint tea.
Experimental: Experimental; Participants will consume two cups of a high rosmarinic acid spearmint tea per day (300 mL in the morning and 300 mL in the evening, providing a total of approximately 300 mg of rosmarinic acid per day) for a total of 4 months.	Other: High Rosmarinic Acid Spearmint Tea; The investigational product will be a high rosmarinic acid spearmint tea (700B) developed by the Department of Plant Agriculture, University of Guelph. Clone 700B has been selectively bred to contain a rosmarinic acid content 15-20 times greater than that of typical mint.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Self-reported ratings of pain and physical function	Data collection of self-reported ratings of pain and physical function (WOMAC), self-reported ratings of overall physical and mental health (SF-36), and self-reported changes in the use of concomitant pain and inflammation medications (study diary) will occur at baseline (week 0), mid-treatment (week 8), post-treatment (week 16), and follow-up (week 20).	Four months
Use of concomitant pain/inflammatory medications for the management of osteoarthritis symptoms		Four months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Performance-based measures of physical function	Data for performance-based assessment of physical function (6-minute walk, stair climb task) will be collected at baseline (week 0), mid-treatment (week 8), post-treatment (week 16), and follow-up (week 20).	Four months
Change in synovial fluid biomarkers of cartilage degradation	In a sub-set of participants, a synovial fluid sample will be drawn (i.e. arthocentesis) for the analyses of cartilage degradation biomarkers (GAG, COMP, PGE2, NO) at baseline (week 0) and post-treatment (week 16).	Four months

Collaborators and Investigators

• Sponsor: University of Guelph
• Collaborators: Ontario Ministry of Agriculture, Food and Rural Affairs
• Investigators: Principal Investigator: Amanda J Wright, Ph.D., Human Nutraceutical Research Unit; Principal Investigator: Alison M Duncan, Ph.D., R.D., Human Nutraceutical Research Unit

Publications and helpful links

General Publications

• Connelly AE, Tucker AJ, Tulk H, Catapang M, Chapman L, Sheikh N, Yurchenko S, Fletcher R, Kott LS, Duncan AM, Wright AJ. High-rosmarinic acid spearmint tea in the management of knee osteoarthritis symptoms. J Med Food. 2014 Dec;17(12):1361-7. doi: 10.1089/jmf.2013.0189.

Study record dates

Study Major Dates

• Study Start: July 1, 2011
• Primary Completion (Actual): November 1, 2012
• Study Completion (Actual): December 1, 2012

Study Registration Dates

• First Submitted: June 21, 2011
• First Submitted That Met QC Criteria: June 23, 2011
• First Posted (Estimate): June 27, 2011

Study Record Updates

• Last Update Posted (Estimate): January 23, 2013
• Last Update Submitted That Met QC Criteria: January 21, 2013
• Last Verified: January 1, 2013

More Information

Terms related to this study

• Keywords: osteoarthritis; spearmint; rosmarinic acid
• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Osteoarthritis, Knee; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Peripheral Nervous System Agents; Enzyme Inhibitors; Analgesics; Sensory System Agents; Anti-Inflammatory Agents, Non-Steroidal; Analgesics, Non-Narcotic; Anti-Inflammatory Agents; Antirheumatic Agents; Platelet Aggregation Inhibitors; Protease Inhibitors; Protective Agents; Serine Proteinase Inhibitors; Antioxidants; Rosmarinic acid
• Other Study ID Numbers: 11JA040