Effects of New Zealand Blackcurrant Supplementation on Exercise and Cognitive Performance in Resistance-Trained Adults

Part of paid clinical trials in Jacksonville, Alabama.

Sponsor
Jacksonville State University
Study ID
NCT07619976
Status
Completed

Conditions

  • Anaerobic Performance
  • Cognitive Function
  • Dietary Supplementation Athletic Performance
  • Resistance Exercise Performance

Eligibility Criteria

Sex
ALL
Age
18 Years - 40 Years
Healthy Volunteers
Accepted

Interventions

  • Low-dose Blackcurrant Supplement — DIETARY_SUPPLEMENT
    A low-dose blackcurrant (250 mg) supplement was administered to examine its effects on anaerobic exercise performance and cognitive function.
  • High-dose Blackcurrant Supplement — DIETARY_SUPPLEMENT
    A high-dose blackcurrant (600 mg) supplement was administered to examine its effects on anaerobic exercise performance and cognitive function.
  • Maltodextrin (Placebo) — DIETARY_SUPPLEMENT
    Maltodextrin capsules matched in appearance to the blackcurrant supplement capsules, serving as an inert placebo control.

Study Details

New Zealand blackcurrant (NZBC) is a supplement made from a berry naturally rich in plant compounds called anthocyanins. Researchers have studied these compounds for years and found that they may help the body by improving blood flow, reducing post-exercise stress on the body, and supporting energy production. Most of that research, however, has focused on endurance athletes like runners and cyclists. Almost nothing was known about whether NZBC could benefit people who do strength training. That is what this study was designed to find out. Twenty healthy, resistance-trained men and women between the ages of 18 and 40 were recruited. Each participant completed four different conditions over the course of the study: taking no supplement at all, taking a placebo (a dummy capsule with no active ingredient), taking a low dose of NZBC (250 mg per day for seven days), and taking a higher dose of NZBC (600 mg per day for seven days). Neither the participants nor the researchers evaluating them knew which capsule was being taken at any given time, a design that helps ensure the results are as reliable as possible. At the end of each seven-day period, participants came into the lab and completed a full battery of tests. Measurements included how much weight could be lifted for one maximum effort on the bench press and leg press, how much total volume could be completed across multiple sets, and how fast and powerfully the bar could be moved. Participants also completed a 30-second all-out cycling sprint to test anaerobic fitness, and a paper-and-pencil color-word test to measure focus and mental sharpness. Strength increased noticeably. After taking either dose of NZBC, participants were able to lift more weight on both the bench press and leg press than when taking the placebo or no supplement. The lower dose had a particularly striking effect on leg training: participants pushed through roughly 38% more total volume in their leg press sets. For bar speed and explosive power on the bench press, the higher dose had the edge. Cognitive performance followed a similar pattern. The lower dose sharpened mental performance across several parts of the color-word test, while the higher dose made a more modest but still meaningful difference on one section. The sprint cycling test showed no differences between conditions. Importantly, both doses were safe and well-tolerated, with no meaningful side effects reported throughout the study. One week of supplementation was sufficient to produce real differences in strength, power, and mental sharpness, and neither dose raised any safety concerns.

Key Dates

Start date
Jan 21, 2023
Status verified
May 2026
Primary completion
Apr 25, 2023
Completion
Jul 10, 2023

Study Design

Enrollment
20 participants (actual)
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE

Arms

  • No Intervention: No-Capsule Control
    No supplement administered. Participants completed all testing procedures without receiving any substance.
  • Placebo Comparator: Placebo
    Participants received maltodextrin capsules matched in appearance to the blackcurrant supplement capsules.
  • Experimental: Low-Dose Blackcurrant
    Participants received 250 mg of blackcurrant supplement per day.
  • Experimental: High-Dose Blackcurrant
    Participants received 600 mg of blackcurrant supplement per day.

Primary Outcome Measure

Resistance Exercise Performance [ Time Frame: Baseline, end of Week 1 (post-supplementation), end of Week 2 (post-washout), and end of Week 3 (post-crossover supplementation); total study duration approximately 3 weeks. ]

Locations (1)

FacilityCityStateZIPSite coordinators
Exercise Physiology and Nutrition Laboratory (EPNL) at Jacksonville State UniversityJacksonvilleAlabama36265-1724-

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By research site
Exercise Physiology and Nutrition Laboratory (EPNL) at Jacksonville State University· Jacksonville, AL

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