Expired Study
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Beltsville, Maryland 20705


The study will consist of a single 5-day dietary treatment period. Subjects will consume an Allium-free diet for 3 days. Alliums are vegetables such as garlic, onions, chives, shallots, and leeks. On day 4, subjects will consume a breakfast consisting of garlic and will then provide blood and urine samples for 10 hours, and on the following morning.


Inclusion Criteria: - Men and women of age 25 to 75 years at beginning of study - BMI between 18.5 and 30 kg/m2 - Fasting glucose < 126 mg/dl - Blood pressure < 160/100 (controlled with certain medications) - Fasting total blood cholesterol < 280 mg/dl - Fasting triglycerides < 300 mg/dl Exclusion Criteria: - Younger than 25 years old or older than 75 years old - Use of blood-thinning medications such as Coumadin (warfarin), Dicumarol (dicumarol), or Miradon (anisindione) - Presence of kidney disease, liver disease, gout, certain cancers, thyroid disease, gastrointestinal, other metabolic diseases or malabsorption syndromes. - Have been pregnant during the previous 12 months, are currently pregnant or lactating, or plan to become pregnant during the study - Type 2 diabetes requiring the use of oral antidiabetic agents or insulin - History of eating disorders or other dietary patterns which are not consistent with the dietary intervention (e.g., vegetarians, very low fat diets, high protein diets) - Use of prescription or over-the-counter antiobesity medications or supplements (e.g., phenylpropanolamine, ephedrine, caffeine) during and for at least 6 months prior to the start of the study or a history of a surgical intervention for obesity - Active cardiovascular disease (such as a heart attack or procedure within the past three months or participation in a cardiac rehabilitation program within the last three months, stroke, or history/treatment for transient ischemic attacks in the past three months, or documented history of pulmonary embolus in the past six months). - Use of any tobacco products in past 6 months - Unwillingness to abstain from herbal supplements for two weeks prior to the study and during the study - Known (self-reported) allergy or adverse reaction to garlic - Inability to tolerate garlic - Unable or unwilling to give informed consent or communicate with study staff - Self-report of alcohol or substance abuse within the past twelve months and/or current acute treatment or rehabilitation program for these problems (Long-term participation in Alcoholics Anonymous is not an exclusion) - Other medical, psychiatric, or behavioral factors that in the judgment of the Principal Investigator may interfere with study participation or the ability to follow the intervention protocol

Study is Available At:

Original ID:




Secondary ID:

Study Acronym:

Brief Title:

Dietary Absorption of Garlic Metabolites Following Garlic Consumption

Official Title:

Overall Status:


Study Phase:




Minimum Age:

25 Years

Maximum Age:

75 Years

Quick Facts

Healthy Volunteers
Oversight Has DMC
Study Is FDA Regulated
Study Is Section 801
Has Expanded Access

Study Source:

USDA Beltsville Human Nutrition Research Center

Oversight Authority:

United States: Federal Government

Reasons Why Stopped:

This study was suspended due to additional t

Study Type:


Study Design:

Endpoint Classification: Pharmacokinetics Study, I

Number of Arms:


Number of Groups:


Total Enrollment:


Enrollment Type:


Study Dates

Start Date:September 2016
Completion Date:December 2016
Completion Type:Anticipated
Primary Completion Date:December 2016
Primary Completion Type:Anticipated
Verification Date:September 2015
Last Changed Date:September 11, 2015
First Received Date:December 8, 2014

Study Outcomes

Outcome Type:Primary Outcome
Measure:N-acetyl-S-trans-1-propenylcysteine sulfoxide
Time Frame:24 hour
Safety Issues:False
Description:Metabolite will be analyzed in blood and urine.
Outcome Type:Primary Outcome
Measure:N-acetyl allylcysteine sulfoxide
Time Frame:24 hour
Safety Issues:False
Description:Metabolite will be analyzed in blood and urine.
Outcome Type:Primary Outcome
Measure:Allyl methyl sulfide
Time Frame:24 hour
Safety Issues:False
Description:Metabolite will be analyzed in blood and urine.

Study Interventions

Intervention Type:Other
Name:Garlic Intervention
Description:Participants will consume an Allium-free controlled diet for 3 days. On the 4th day, they will consume a test meal containing garlic followed by blood and urine collections for 10 hours. On the 5th day, participants will have a fasting blood and urine collection.
Arm Name:Time Course

Study Arms

Study Arm Type:Experimental
Arm Name:Time Course
Description:Measurement of garlic metabolites over 24 hours following garlic intervention.

Study Agencies

Agency Class:U.S. Fed
Agency Type:Lead Sponsor
Agency Name:USDA Beltsville Human Nutrition Research Center

Sample and Retention Information

There are no available Sample and Retention Information

Study References

There are no available Study References

Data Source: ClinicalTrials.gov

Date Processed: January 21, 2020

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