Identifying the Anti-Blood-Clotting Compounds in Garlic

December 4, 2009 updated by: National Center for Complementary and Integrative Health (NCCIH)

Identification of the Antiplatelet Compounds of Garlic Ex Vivo

This study will seek to identify the compound(s) in garlic that is (are) responsible for its ability to prevent the formation of blood clots (prevent platelet aggregation) and to determine the maximally effective dose and duration of the benefits. This study will also determine whether "cooked" garlic (garlic powder added to boiling water, no allicin present) is as effective as "fresh" garlic (garlic powder added to ambient water, high allicin present) and, if more than one compound is involved, and whether their combined effects are more significant than the effects of each compound alone.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Published studies indicate that various types of undefined garlic products display antiplatelet activity. However, the compounds responsible for this antiplatelet effect have not been identified.

Acute studies. In acute (one day) studies, healthy participants will consume several doses of "fresh garlic" (garlic powder added to ambient water; up to the equivalent of 12 grams fresh garlic or 52 mg allicin) as a paste in a tuna sandwich. At 0, 2, 4, and 6 hours after consumption, the ability of platelets to aggregate in platelet-rich plasma (PRP) or in whole blood (WB), in response to a drug (collagen, ADP) that stimulates platelet aggregation, will be measured. After establishing the optimum dose and optimum time of the antiplatelet effect for each person, and if the effects are sufficiently strong, the effects of cooked garlic (garlic powder added to boiling water, no allicin present) and seven extracted fractions (oil, protein, fructans, etc.) will be determined, using the fractions at the same dose as their abundance in the established optimum dose of crushed fresh garlic.

Chronic studies. If only weak platelet effects are found for a high acute dose of "fresh" garlic, chronic studies will be conducted. In chronic studies, participants will consume 8.0 grams of "fresh garlic" (2.7 grams garlic powder added to ambient water, allicin content = 35 mg) as a paste in a tuna sandwich every day for four weeks and 8.0 grams of "boiled garlic" (2.7 grams garlic powder added to boiling water) in a sandwich every day for an additional four weeks, after a 1-week washout. The ability of platelets to aggregate in PRP and whole blood will be determined before and every week after garlic consumption begins and after the 1-week washout.

Study Type

Interventional

Enrollment (Actual)

9

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Utah
      • Orem, Utah, United States, 84058
        • Silliker, Inc./Plant Bioactives Research Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Body mass index of 19 to 30 kg/m2
  • Plans to remain in the study area for the next year
  • Willingness to abstain from nonsteroidal anti-inflammatory drugs (NSAID drugs for 1 week prior to each study test
  • Willingness to abstain from consuming garlic and significant amounts of onion, chocolate, or purple grape juice for 3 days prior to each study test
  • Willingness to participate in all study tests

Exclusion Criteria:

  • Pregnancy or breast-feeding
  • Serious medical condition
  • Allergy to garlic or wheat
  • Tobacco use
  • Excessive alcohol consumption
  • Under psychiatric care

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Non-Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Garlic powder in ambient water
high allicin
Dietary supplement: garlic powder added to ambient water
consumed 2.7 grams of garlic powder added to ambient water (equivalent to 8 grams fresh or raw garlic) in a sandwich, once a day for four weeks
Other Names:
  • Global Marketing Assoc., Inc.
Experimental: garlic powder in boiling water
no allicin
Dietary supplement: garlic powder added to boiling water
consumed 2.7 grams of garlic powder added to boiling water (equivalent to 8 grams of cooked garlic) in a sandwich, once a day for four weeks
Other Names:
  • Global Marketing Assoc., Inc.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percent Platelet Aggregation
Time Frame: 4 weeks
percent platelet aggregation in collagen-induced platelet aggregation in platelet rich plasma (PRP)
4 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Electrical Impedance in Ohms
Time Frame: 4 weeks
Electrical impedance (ohms) was measured using 0.5 mL of whole blood plus 0.5 mL saline in a Chronolog Whole Blood aggregometer. Ten mL of whole blood were collected and tested every week. There is no mathematical correlation between impedance (ohms) and percent aggregation.
4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Center for Complementary and Integrative Health (NCCIH)

Investigators

  • Principal Investigator: Larry D. Lawson, PhD, Silliker, Inc./Plant Bioactives Research Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

March 1, 2006

Primary Completion (Actual)

September 1, 2007

Study Completion (Actual)

September 1, 2007

Study Registration Dates

First Submitted

September 12, 2005

First Submitted That Met QC Criteria

September 12, 2005

First Posted (Estimate)

September 20, 2005

Study Record Updates

Last Update Posted (Estimate)

January 11, 2010

Last Update Submitted That Met QC Criteria

December 4, 2009

Last Verified

December 1, 2009

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • R21AT001512-01 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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