Effects of Dietary Antioxidants on Cardiovascular Risk Factors

Not Applicable

Completed

• Conditions: Obesity; Hyperlipidemia; Hypertension
• Interventions: Behavioral: Antioxidant diet; Dietary Supplement: Antioxidant supplement; Dietary Supplement: Placebo

• Registration Number: NCT00756405
• Lead Sponsor: Christopher Gardner

Brief Summary

The aim of the Antioxidant Study was to compare the efficacy of foods naturally rich in antioxidants with that of antioxidants in a pill form on markers of inflammation and plasma cholesterol in healthy adults at risk of cardiovascular disease.

Detailed Description

Increasing the amount of antioxidants in your diet is thought to be one way to improve your health. If antioxidants do have a beneficial effect, one way to measure that is to examine possible changes in the levels of inflammatory markers in your blood.

Participants were asked to consume an antioxidant supplement including carotenoids, mixed tocopherols, vitamin C and selenium, or a placebo for 8 weeks. The doses of antioxidants will be similar to the amounts suggested by the United States Department of Agriculture (USDA) recommended daily allowances (RDA). In addition, a group of participants will be asked to change their usual eating habits and consume more of certain foods that are naturally good sources of the four antioxidants contained in the pills.

Eligible participants were asked to come to the Stanford Campus for 3 fasting blood draws over the period of 8 weeks and to complete diet and physical activity questionnaires at the beginning, middle, and end of the study period.

Study Timeline

• Study Start: 2007-03
• Study First Submitted: 2008-09-19
• Study First Submitted QC: 2008-09-19
• Study First Posted: 2008-09-22
• Primary Completion: 2008-12
• Study Completion: 2008-12
• Status Verified: 2023-02
• Last Update Submitted: 2023-02-18
• Last Update Posted: 2023-02-22

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 88

Inclusion Criteria

Overweight/obesity; high LDL cholesterol, pre-hypertension.

Exclusion Criteria

1. Daily intake of > 5 servings of vegetables and fruits 2. Fasting blood glucose >140 mg/dL 3. BMI >40 4. Liver or renal disease; Atherosclerosis (e.g., CAD, PAD); Malignant neoplasm; Ongoing infection; Inflammatory disease 5.Currently taking the following medications: Anti-inflammatory drugs Lipid lowering drugs Anti-hypertensive drugs Calcium containing drugs Drugs known to affect blood coagulation Drugs known to affect antioxidant status 6. Pregnant or lactating 7. Inability to communicate effectively with study staff

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Diet Group	Antioxidant diet	Increased antioxidant diet and placebo pill.
Diet Group	Placebo	Increased antioxidant diet and placebo pill.
Supplement Group	Antioxidant supplement	Usual diet and antioxidant supplement.
Placebo	Placebo	Usual diet and placebo pill.

Primary Outcome Measures

Name	Time	Method
Change from baseline in inflammatory Markers [monocyte chemotactic protein-1 (MCP-1), interleukin-6 (IL-6), and soluble intercellular adhesion molecule-1 (sICAM-1)] at 8 weeks	Baseline and 8 weeks	Change was calculated as the value at 8 weeks minus the value at baseline

Secondary Outcome Measures

Name	Time	Method
Dietary antioxidants	Baseline and 8 weeks	Dietary intake of carotenoids, tocopherols, selenium, and vitamin C (as measured by 3-day dietary recalls)
Blood concentrations of antioxidants at baseline and 8 weeks	Baseline and 8 weeks	Blood concentrations of carotenoids, tocopherols, selenium, and vitamin C (to validate dietary change)

Trial Locations

Locations (1)

Stanford University School of Medicine; 🇺🇸 Stanford, California, United States