Arteriosclerosis, Intracranial Arteriosclerosis
Conditions
Keywords
garlic
Brief summary
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.
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.
Interventions
DIETARY_SUPPLEMENTgarlic 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
DIETARY_SUPPLEMENTgarlic 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
Sponsors
National Center for Complementary and Integrative Health (NCCIH)
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percent Platelet Aggregation | 4 weeks | percent platelet aggregation in collagen-induced platelet aggregation in platelet rich plasma (PRP) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Electrical Impedance in Ohms | 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. |
Countries
United States
Participant flow
Recruitment details
healthy participants were recruited in Utah county, Utah, in early 2006
Participants by arm
| Arm | Count |
|---|---|
| Garlic Powder: High Allicin garlic powder in ambient water | 9 |
| Garlic Powder: No Allicin garlic powder in boiling water | 6 |
| Total | 15 |
Baseline characteristics
| Characteristic | Garlic Powder: No Allicin | Garlic Powder: High Allicin | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0.0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0.0 Participants |
| Age, Categorical Between 18 and 65 years | 6 Participants | 9 Participants | 15.0 Participants |
| Age Continuous | 36.5 years STANDARD_DEVIATION 15.1 | 32.2 years STANDARD_DEVIATION 13.7 | 32.2 years STANDARD_DEVIATION 13.7 |
| electrical impedance (ohms) at 0 weeks | 15.0 ohms STANDARD_DEVIATION 1.6 | 12.7 ohms STANDARD_DEVIATION 1.2 | 13.9 ohms STANDARD_DEVIATION 1.4 |
| percent platelet aggregation at 0 weeks | 71.8 percent platelet aggregation STANDARD_DEVIATION 5.7 | 76.0 percent platelet aggregation STANDARD_DEVIATION 1.6 | 73.9 percent platelet aggregation STANDARD_DEVIATION 3.7 |
| Region of Enrollment United States | 6 participants | 9 participants | 15.0 participants |
| Sex: Female, Male Female | 3 Participants | 4 Participants | 7.0 Participants |
| Sex: Female, Male Male | 3 Participants | 5 Participants | 8.0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 9 | 0 / 6 |
| serious Total, serious adverse events | 0 / 9 | 0 / 6 |
Outcome results
Primary
Percent Platelet Aggregation
percent platelet aggregation in collagen-induced platelet aggregation in platelet rich plasma (PRP)
Time frame: 4 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Garlic Powder: High Allicin | Percent Platelet Aggregation | 71.4 percent platelet aggregation | Standard Deviation 4.3 |
| Garlic Powder: No Allicin | Percent Platelet Aggregation | 72.5 percent platelet aggregation | Standard Deviation 5.5 |
Secondary
Electrical Impedance in Ohms
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.
Time frame: 4 weeks
Population: Nine persons participated in the high allicin test. Six of the same persons participated in the no allicin test.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Garlic Powder: High Allicin | Electrical Impedance in Ohms | 13.8 ohms | Standard Deviation 1.5 |
| Garlic Powder: No Allicin | Electrical Impedance in Ohms | 15.0 ohms | Standard Deviation 1.5 |