The Kyolic Garlic & Aerobic Fitness Trial

Update June 2025: 

Abstract:

Background

Arterial stiffness is a cardiovascular risk factor that increases with age. Kyolic aged garlic extract has been shown to reduce arterial stiffness, while normalizing blood pressure, cholesterol and blood thickness. The present study hypothesized that increased flexibility of arteries could lead to slower blood flow and increased oxygen uptake and overall aerobic fitness. The present 12 week trial aimed to assess the effect of Kyolic aged garlic extract (AGE) on arterial stiffness, aerobic fitness, lactate threshold, recovery from muscle soreness and cardiovascular proteomic biomarkers in middle‑aged (40‑65 years) endurance athletes with elevated arterial stiffness.

Methods

A total of 75 middle‑aged recreational endurance athletes completed the trial, after being randomly allocated for 12 weeks to either the placebo or Kyolic aged garlic extract groups: low‑dose cohort 1 (n=37), 2 capsules/day containing 1.2 g AGE powder and 1.2 mg S‑allylcysteine (SAC); and the high‑dose cohort 2 (n=38), 4 capsules/day of 2.4 g AGE powder and 2.4 mg SAC. Arterial stiffness was assessed through pulse wave velocity measurements and aerobic fitness was measured by volume‑maximal‑oxygen‑consumption (VO₂max) and lactate thresholds during high‑intensity exercise using a cycle‑ergometer‑test‑station, as well as measuring the levels of muscle fatigue and recovery time at 12 weeks compared with the baseline results. Urinary proteomic analysis was performed in a subgroup of participants and measured the levels of certain relevant proteins used as biomarkers for risk of cardiovascular events, at 12 weeks compared with baseline results.

Results

The Kyolic aged garlic extract group significantly improved their aerobic fitness, as was evidenced by increased VO2max, increased aerobic power, higher lactate threshold‑to‑oxygen uptake, higher lactate threshold‑to‑power output and quicker recovery times compared with the placebo group. Pulse wave velocity, a measure for arterial flexibility, was improved in the Kyolic aged garlic extract group compared with the placebo. The proteomics analysis demonstrated that a subset of polypeptides associated with cardiovascular risk, such as heart attacks and stroke, decreased in the Kyolic aged garlic extract group at 12 weeks compared with the baseline, which was contrary to the effects observed in the placebo group.

Conclusions

The study results suggest Kyolic aged garlic extract significantly improved aerobic fitness, lactate threshold, recovery and cardiovascular proteomic biomarkers in middle‑aged endurance athletes within 12 weeks.

 

Update Oct 2023: Recruitment for the trial is now closed.  Thank you for your interest.

Any questions? Contact:  research@niim.com.au

Effect of Kyolic aged garlic extract on arterial stiffness and aerobic fitness in 40-65 year old active adults: a dose-response trial

Arterial stiffness is a cardiovascular risk factor, which increases naturally with age. Kyolic garlic has been shown to improve the flexibility of arteries, and slows down blood flow, which may improve oxygen uptake, associated with aerobic fitness.

In this randomised double-blind placebo-controlled 12-week trial we aim to assess the effect and dose-response of Kyolic garlic on arterial stiffness and aerobic fitness in 40-65 year old active adults with elevated arterial stiffness.

In this study, we aim to assess the effect of Kyolic aged garlic extract on:

 

1. Arterial stiffness, assessed by measuring how fast your blood travels through your blood vessels (pulse wave analysis)
2. Aerobic fitness, assessed by high intensity exercise VO₂max test on a cycle ergometer
3. Lactate threshold, assessed by lactate levels during VO₂max testing
4. Muscular soreness and recovery, assessed by questionnaire
5. Cardiovascular proteomic biomarkers, assessed by urine spot test (subgroup)
6. Microcirculation, assessed by video microcapillary microscopy

Update Oct 2023:  Recruitment for the trial is now closed. 

Participants:

• 40-65 year old active adults with elevated arterial stiffness*

 

• who regularly undertake a minimum of 3x30min/week moderate to high intensity exercise (e.g. triathlon, cycling, running, swimming)

*To assess eligibility, you will need to attend a 30 min screening visit at NIIM, where we will test your arterial stiffness with a hand-held gold-standard blood pressure tonometer.

Eligible participants will 

 

1. Attend 4 appointments at NIIM over a 3 months period, at baseline, 4 weeks, 8 weeks, and 12 weeks.
2. Attend 2 appointments at METS Performance Consulting in Mulgrave, VIC at baseline and after 12 weeks, to undertake the VO₂max testing on a cycle ergometer. Please allow at least 1 hour for testing.
3. Take 2-4 trial capsules a day for 3 months.

In this randomised placebo-controlled double-blind dose-response trial, half of the participants will be randomly allocated to the active capsules which contain the odourless aged garlic extract (Kyolic®), and half of the participants will receive placebo capsules.  

The study will be conducted at NIIM, 21 Burwood Road, Hawthorn VIC 3122.

Please note – Participants need to be located in Victoria, and need to be able to come to the NIIM clinic in Melbourne.