Nutritional Intervention With Black Garlic

Clinical Trial to Evaluate the Efficacy of Black Garlic in Reducing Cardiovascular Risk in Subjects With Hypercholesterolemia

A controlled clinical intervention study is proposed to determine the effect of black garlic consumption on biomarkers of cardiovascular function and associated pathologies in a healthy population at risk for cardiovascular disease. Black garlic is the result of a fermentation process of common white garlic in which the temperature and humidity are kept constant over a long period of time. Black garlic is particularly rich in phenolic compounds such as S-allylcysteine or S-allyl-mercaptocysteine, with antioxidant action. It also provides vitamin C and other valuable antioxidant substances such as flavonoids.

Study Overview

• Status: Active, not recruiting
• Conditions: Inflammation; Hypertension; Hypercholesterolemia; Hyperlipidemias; Endothelial Dysfunction
• Intervention / Treatment: Dietary supplement: black garlic

Detailed Description

A parallel, controlled clinical trial will be performed to assess the effect of garlic on mild hypercholesterolemia.

The study will conducted in two groups of volunteer: healthy and at cardiovascular risk (hypercholesterolemic subjects), consuming black garlic, with each individual acting as its own control. The study will have a total duration of 18 weeks, divided in two stages:

• Stage 1: basal or washout stage of 2 weeks, in which volunteer follow their usual diet with restrictions
• Stage 2: intervention stage of 16 weeks, in which volunteer consume black garlic Sixty healthy volunteers (men and women) between 40-65 years old and BMI between 24.9-29.9 kg/m2 will be recruited. From the total of volunteer, 30 will correspond to the Healthy Group, which should have total blood cholesterol levels less than 200 mg/dL and LDL-cholesterol less than 135 mg/dL.

The other 30 volunteers correspond to the Cardiovascular Risk Group, which should have total cholesterol levels between 200-300 mg/dL and LDL-cholesterol levels between 135-175 mg/dL.

Other inclusion criteria established for all volunteers are: no acute or chronic pathology, (except hypercholesterolemia for the risk group), no taking drugs, hormones or dietary supplements, no smoking, no pregnancy, no vegetarianism.

The study has been approved by the Ethical Committee of Catholic University of Murcia (UCAM) and will be carried out in accordance with the Helsinki Declaration of Human Studies. Recruitment will take place at various Health Centers and at UCAM. All participants will be informed on the characteristics of the study and, after signing the informed consent, a routine analysis will be requested to classify the volunteer in the healthy or cardiovascular risk group.

To avoid bias due to gender, the number of women and men recruited in both groups will be balanced. The size of the study population has been estimated taking total blood cholesterol level as the main variable and taking into account that the study design is randomized and parallel. Considering a statistical power of 80%, a statistical significance level of 5% (one tail), a standard deviation of 6.5, aiming to estimate a difference of 2.5, the number of volunteers required is 25 for each group, rising to 30 in anticipation of dropouts. This number, being two study groups, will allow obtaining results with statistical significance in other biochemical parameters that would be determined as secondary variables of the study and that would inform on the effect of black garlic consumption on cardiovascular function and associated dysfunctions (inflammation, hypertension, endothelial function, diabetes, etc.).

After an initial washout (basal) stage common to all groups, in which the volunteers will consume their usual diet with restriction in the consumption of fresh garlic and garlic products, the intervention will start, with the consumption of black garlic for 12 weeks. Volunteers will be provided with black garlic and they will ensure that no other type of garlic or culinary seasoning is used.

Dietary and physical activity questionnaire according to the "Global Physical Activity Questionnarie (GPAQ)" will be compiled in order to collect information on habits and lifestyle, as well as to ensure the compliance of food restrictions.

During the study, visits will be scheduled on the first day and last day of each stage. The subjects will come to the Unit on fasting conditions and will provide the first morning urine. Blood sample will be taken, plasma aliquoted and stored at -80°C until analysis.

• Study Type: Interventional
• Enrollment (Actual): 62
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Murcia, Spain, 30107
    • Universidad Católica de Murcia (UCAM)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

Healthy Group:

• Total blood cholesterol levels of less than 200 mg/dL
• LDL-cholesterol levels of less than 135 mg/dL
• Not suffer from any other pathology.
• No drugs, hormones or dietary supplements, no smoking, no pregnancy, no vegetarianism, etc.

Cardiovascular Risk Group:

• Total cholesterol levels between 200-300 mg/dL
• LDL-cholesterol levels between 135-175 mg/dL.
• No acute or chronic pathology, except hypercholesterolemia
• No drugs, hormones or dietary supplements, no smoking, no pregnancy, no vegetarianism, etc.).

Exclusion Criteria:

• Failure to meet any of the inclusion criteria

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Healthy Group,; Daily consumption of 4 cloves of black garlic, not cooked, during 12 weeks	Dietary supplement: black garlic; Daily consumption of 4 cloves of black garlic, not cooked, during 12 weeks
Experimental: Hypercholesterolemia; Daily consumption of 4 cloves of black garlic, not cooked, during 12 weeks	Dietary supplement: black garlic; Daily consumption of 4 cloves of black garlic, not cooked, during 12 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Impact on blood pressure	Blood pressure (diastolic, systolic)	changes observed from baseline at day 0 compared to 12 weeks.
Impact on lipid profile	Plasma levels of total cholesterol, HDL, LDL, VLDL (very low-density lipoprotein), triglycerides, apolipoproteins A1 and B.	changes observed from baseline at day 0 compared to 12 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Impact on blood cells (Hematology)	Blood counts	changes observed from baseline at day 0 compared to 12 weeks.
evaluation of liver function to determine product safety	Hepatic enzymes (GOT, GPT)	changes observed from baseline at day 0 compared to 12 weeks.
Changes in cytokine levels	Plasma levels of pro-inflammatory: IL-1β, IL6 , TNF-α (tumor necrosis factor) and anti-inflammatory (IL-10, IL-17) cytokines.	changes observed from baseline at day 0 compared to 12 weeks.
Changes in chemokine MCP-1 (monocyte chemotactic protein)	Plasma levels of chemokine MCP-1	changes observed from baseline at day 0 compared to 12 weeks.
Changes in C reactive protein	Plasma levels of C reactive protein	changes observed from baseline at day 0 compared to 12 weeks.
Impact on endothelial function	Plasma levels of nitric oxide, adhesion molecules VCAM-1 (vascular endothelial cell adhesion molecule), ICAM-1 (intercellular adhesion molecule), chemokines as markers of endothelium (E-selectin) and platelet (P-selectin) activation.	changes observed from baseline at day 0 compared to 12 weeks.
Impact on glucose levels	Plasma levels of glucose	changes observed from baseline at day 0 compared to 12 weeks.
Impact on glycosylated hemoglobin (HbA1c)	Plasma levels of glycosylated hemoglobin	changes observed from baseline at day 0 compared to 12 weeks.
Impact in hormones related to metabolism	Plasma levels of thyroid hormones (TSH, T3, T4).	changes observed from baseline at day 0 compared to 12 weeks.

Collaborators and Investigators

• Sponsor: Maria Pilar Zafrilla Rentero
• Collaborators: Instituto de Investigación y formación agraria y pesquera (IFAPA)

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2020
• Primary Completion (Actual): June 30, 2021
• Study Completion (Anticipated): November 30, 2021

Study Registration Dates

• First Submitted: June 8, 2021
• First Submitted That Met QC Criteria: October 15, 2021
• First Posted (Actual): October 18, 2021

Study Record Updates

• Last Update Posted (Actual): October 18, 2021
• Last Update Submitted That Met QC Criteria: October 15, 2021
• Last Verified: October 1, 2021

More Information

Terms related to this study

• Keywords: endothelial dysfunction; inflammation; hypercholesterolemia; black garlic; sulphur bioactive compounds; hyperlipemia
• Additional Relevant MeSH Terms: Pathologic Processes; Metabolic Diseases; Lipid Metabolism Disorders; Dyslipidemias; Inflammation; Hypercholesterolemia; Hyperlipidemias
• Other Study ID Numbers: CFE/IF/28-20

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No