New Zealand Blackcurrant and Recovery in Elite Taekwondo

NCT07828444 | Completed

• 1 other identifier: Hacettepe1234
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized, double-blind, placebo-controlled trial evaluated the effects of short-term supplementation with anthocyanin-rich New Zealand blackcurrant (NZBC) extract on exercise-induced muscle damage, oxidative stress, antioxidant status, inflammatory responses, and perceived muscle soreness in elite male taekwondo athletes. Thirty national-level male taekwondo athletes were enrolled and randomly assigned in a 1:1 ratio to receive either NZBC extract (CurraNZ®, UK; 600 mg/day providing approximately 210 mg anthocyanins) or a matched placebo for 7 days. Blood samples and muscle soreness ratings were collected at baseline, immediately after exercise, 24 hours after exercise, and after 7 days. The primary outcome was plasma creatine kinase (CK). Secondary outcomes included reactive oxygen species (ROS), total antioxidant capacity (TOAC), protein carbonyls, inflammatory cytokines (IL-6, TNF-α, and IL-10), and perceived muscle soreness assessed using a visual analog scale (VAS). The study was approved by the Biruni University Clinical Research Ethics Committee (No. 2015-KAEK-80-23-33; December 22, 2023). Written informed consent was obtained from all participants.

Conditions

Oxidative Stress; Inflammation; Recovery After Exercise; Exercise-induced Muscle Damage

Keywords

New Zealand blackcurrant; Ribes nigrum; anthocyanins; polyphenols; dietary supplement; taekwondo; combat sports; elite athletes; high-intensity training; visual analog scale (VAS); inflammation biomarkers

Outcome Measures

Primary Outcomes (1)

• Change in plasma Creatine Kinase (CK) concentration

  Plasma creatine kinase (CK) activity measured via ELISA assay as a biomarker of exercise-induced muscle damage. The outcome represents the change in CK levels from baseline to 24 h and 7 d after repeated high-intensity training sessions.

  Baseline, immediately post-exercise, 24 hours, and 7 days after training

Secondary Outcomes (4)

• Change in Reactive Oxygen Species (ROS) levels

  Baseline, immediately post-exercise, 24 hours, and 7 days

• Change in Total Antioxidant Capacity (TOAC)

  Baseline, 24 hours, and 7 days

• Change in Inflammatory Cytokines (IL-6, TNF-α, IL-10)

  Baseline, 24 hours, and 7 days

• Perceived Muscle Soreness (Visual Analog Scale, VAS)

  Baseline, 12 hours, 24 hours after each training day, and 7 days

Study Arms (2)

New Zealand Blackcurrant Extract (NZBC)

EXPERIMENTAL

Participants received New Zealand blackcurrant extract capsules (CurraNZ®, Healthspan Elite, UK) for 7 days. The daily dose was 600 mg (two 300 mg capsules, morning and evening), providing approximately 210 mg anthocyanins per day.

Dietary Supplement: New Zealand Blackcurrant Extract (CurraNZ®)

Placebo

PLACEBO COMPARATOR

Participants received placebo capsules identical in appearance to the NZBC capsules, containing maltodextrin. The placebo was administered orally twice daily for 7 days.

Dietary Supplement: Placebo (Maltodextrin)

Interventions

New Zealand Blackcurrant Extract (CurraNZ®) DIETARY_SUPPLEMENT

Standardized anthocyanin-rich blackcurrant extract administered orally at 600 mg/day (two 300 mg capsules) for 7 consecutive days. Each capsule contained natural polyphenolic compounds standardized to \~35% anthocyanins.

New Zealand Blackcurrant Extract (NZBC)

Placebo (Maltodextrin) DIETARY_SUPPLEMENT

Two identical capsules containing maltodextrin, taken daily for 7 days (morning and evening), matching the NZBC supplementation schedule.

Placebo

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male national-level taekwondo athletes actively training and competing
• Age between 18 and 35 years
• Free from any chronic disease, metabolic disorder, or recent musculoskeletal injury
• Not using antioxidant, anti-inflammatory, or ergogenic supplements within the last 4 weeks
• Willing to maintain regular diet and training schedule during the study period
• Provided written informed consent

You may not qualify if:

• Female athletes
• Presence of chronic illness, injury, or infection
• Use of antioxidant or anti-inflammatory supplements in the 4 weeks prior to enrollment
• Dietary habits incompatible with the intervention (e.g., high anthocyanin intake from other sources)
• Failure to complete all study visits or provide required blood samples
• Withdrawal of consent at any time

Sponsors & Collaborators

• Hacettepe University: lead

Study Sites (1)

Okan university

Istanbul, Tuzla, 34000, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Inflammation

Interventions

maltodextrin

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Double-blind study: both participants and investigators were unaware of group allocation. Capsules were identical in appearance and coded by an independent researcher.
• Purpose: SUPPORTIVE CARE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Prof.

Model Details: A parallel two-arm design with random assignment to New Zealand blackcurrant extract or placebo for 7 days.

Study Record Dates

• First Submitted: September 14, 2026
• First Posted: September 18, 2026
• Study Start: December 1, 2023
• Primary Completion: June 1, 2024
• Study Completion: June 30, 2024
• Last Updated: September 18, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, ANALYTIC CODE
• Time Frame: Deidentified IPD and supporting documents will be available beginning 1 month after publication of the primary results and for 36 months thereafter. If publication is delayed, access will begin 12 months after database lock. Extensions may be granted upon justified request.
• Access Criteria: Qualified researchers with a methodologically sound proposal may request access by emailing the corresponding author (Assoc. Prof. Sedat Arslan; sarslan@bandirma.edu.tr). Requests must include a brief protocol, objectives, analysis plan, and IRB/ethics determination (if applicable). A data use agreement is required. Only deidentified IPD (baseline characteristics and prespecified outcomes) and documentation (protocol, SAP, ICF templates, analytic code) will be shared. Data will be provided via a secure institutional repository link; re-identification and commercial use are prohibited.

Locations

TU (1)