Aged Garlic Extract:
Research Overview
This page provides a curated overview of selected peer-reviewed scientific studies examining aged garlic extract (AGE), a standardized garlic preparation. The summaries below describe findings reported in published human clinical studies and are presented for educational purposes as part of a clinician-led review of the scientific literature. This page does not contain product recommendations or affiliate links.
Important Context for Readers
Scientific studies examine outcomes in defined populations under specific research conditions. Results reported in individual studies may not apply to all individuals and should not be interpreted as guaranteed outcomes.
This page summarizes selected research examining cardiovascular and blood pressure support, vascular function, immune function, and metabolic biomarkers in relation to aged garlic extract. It is not intended to provide medical advice, diagnosis, or treatment recommendations. This page is provided for educational purposes and does not include product recommendations or affiliate links.
Summary of Evidence
Across human clinical studies and meta-analyses, aged garlic extract has been studied for its potential influence on cardiovascular, metabolic, and inflammatory biomarkers.
In selected study populations, reported findings have included:
• Some studies and meta-analyses have reported modest changes in blood pressure, including reductions in systolic blood pressure in the range of approximately 5–10 mmHg and diastolic blood pressure in the range of approximately 3-6 mmHg in selected hypertensive populations
• Changes in vascular function and arterial stiffness have been evaluated in clinical studies
• Changes in lipid-related biomarkers have been reported in some studies
• Changes in immune and oxidative stress–related biomarkers have been observed in clinical research
The magnitude of changes varies depending on study design, formulation, dose, and population characteristics. Some meta-analyses include multiple garlic preparations and are presented for broader context.
Key Areas of Research
Blood Pressure Support
Evidence strength: Moderate–Strong.
1) Ried K, Frank OR, Stocks NP, et al. Effect of garlic on blood pressure: a systematic review and meta-analysis. BMC Cardiovasc Disord. 2008.
PMID: 18554422
DOI: https://doi.org/10.1186/1471-2261-8-13
Design: Meta-analysis of randomized controlled trials
Key findings:
• Reductions in systolic (~8–10 mmHg) and diastolic (~5–6 mmHg) blood pressure were reported in hypertensive populations across pooled analyses
2) Ried K, Frank OR, Stocks NP, et al. Aged garlic extract lowers blood pressure in patients with treated but uncontrolled hypertension: a randomised controlled trial. Maturitas. 2010.
PMID: 20594781
DOI: https://doi.org/10.1016/j.maturitas.2010.06.001
Design: Randomized controlled trial
Key findings:
• Reductions in systolic blood pressure were reported in the aged garlic extract group compared with placebo
• Changes in diastolic blood pressure were also reported
• A proportion of participants were reported to achieve reductions in blood pressure during the intervention period
• Inter-individual variability in response was observed across the study population
3) Ried K, Frank OR, Stocks NP. Aged garlic extract reduces blood pressure in hypertensives: a dose-response trial. Eur J Clin Nutr. 2013.
PMID: 23169470
DOI: https://doi.org/10.1038/ejcn.2012.178
Design: Randomized, double-blind, placebo-controlled trial
Key findings:
• Reductions in systolic blood pressure (~7.4–11.8 mmHg) were reported in the study population
• Dose–response relationship observed
4) Ried K, Travica N, Sali A. The effect of aged garlic extract on blood pressure and other cardiovascular risk factors in uncontrolled hypertensives: the AGE at Heart trial. Integr Blood Press Control. 2016.
PMID: 26834403
DOI: https://doi.org/10.2147/IBPC.S93335
Design: Randomized controlled trial
Key findings
• Reductions in systolic blood pressure, including values in the range of approximately 5-11.5 mmHg, were reported in the study population
• Changes in arterial stiffness measures were reported
Vascular Function and Atherosclerosis
Evidence strength: Moderate.
5) Matsumoto S, Nakanishi R, Li D, et al. Aged garlic extract reduces low attenuation plaque in coronary arteries of patients with metabolic syndrome in a prospective randomized double-blind study. J Nutr. 2016.
PMID: 26764322
DOI: https://doi.org/10.3945/jn.114.202424
Design: Randomized controlled trial
Key findings:
• Changes in low-attenuation plaque volume were observed in the aged garlic extract group compared with placebo
• Differences in non-calcified plaque characteristics were reported over the study period
• Findings suggest potential effects on coronary plaque–related imaging markers in the study population
6) Budoff MJ. Aged garlic extract retards progression of coronary artery calcification. J Nutr. 2006.
PMID: 16484554
DOI: https://doi.org/10.1093/jn/136.3.741S
Design: Randomized controlled trial
Key findings:
• Changes in coronary artery calcification (CAC), a marker of vascular health, were evaluated in a randomized trial
• Findings suggest potential effects on vascular imaging markers within the study population
Immune Function
Evidence strength: Moderate.
7) Nantz MP, Rowe CA, Muller CE, et al. Supplementation with aged garlic extract improves both NK and γδ-T cell function and reduces the severity of cold and flu symptoms: A randomized, double-blind, placebo-controlled nutrition intervention. Clin Nutr. 2012.
PMID: 22280901
DOI: https://doi.org/10.1016/j.clnu.2011.11.019
Design: Randomized controlled trial
Key findings:
• Symptom severity measures related to cold and flu were evaluated
• Changes in natural killer (NK) and γδ-T cell activity (a type of immune cell) were reported in the study population
Metabolic, Inflammatory, & Microbiome
Outcomes
Evidence strength: Emerging–Moderate.
8) Ried K, Toben C, Fakler P. Effect of garlic on serum lipids: an updated meta-analysis. Nutrition Reviews. 2013.
PMID: 23590705
DOI: https://doi.org/10.1111/nure.12012
Design: Meta-analysis of randomized controlled trials
Key findings:
• Changes in lipid parameters, including total cholesterol (~17 mg/dL reduction) and LDL cholesterol (~9 mg/dL reduction), were reported across pooled analyses
9) Moosavian SP, Arab A, Paknahad Z, et al. The effects of garlic supplementation on oxidative stress markers: a systematic review and meta-analysis of randomized controlled trials. Complement Ther Med. 2020.
PMID: 32444050
DOI: https://doi.org/10.1016/j.ctim.2020.102385
Design: Systematic review and meta-analysis of randomized controlled trials
Key findings:
• Pooled analyses suggested changes in oxidative stress–related biomarkers, including measures of antioxidant capacity and lipid peroxidation
• Changes in markers of oxidative balance were reported across several included studies
• Substantial heterogeneity was noted across study designs, populations, and garlic preparations
10) Ried K, Travica N, Sali A.The Effect of Kyolic Aged Garlic Extract on Gut Microbiota, Inflammation, and Cardiovascular Markers in Hypertensives: The GarGIC Trial. Frontiers in Nutrition. 2018.
PMID: 30619868
DOI: https://doi.org/10.3389/fnut.2018.00122
Design: Randomized controlled trial
Key findings:
• Changes in gut microbiota composition were observed following supplementation
• Increases in microbial diversity and shifts in selected bacterial taxa were reported
• Inflammatory and cardiovascular-related biomarkers were evaluated, with variable changes observed
Educational Notice
These summaries are provided for educational purposes and describe findings reported in scientific studies. They are not intended to provide medical advice, diagnosis, or treatment recommendations.
FDA Disclaimer
These statements have not been evaluated by the U.S. Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease.
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