We updated the design of this site on December 18, 2017. Learn more.
ClinicalTrials.gov Menu

Postprandial Effects of Walnut Components Versus Whole Walnuts on Cardiovascular Disease (CVD) Risk Reduction

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00938340
Recruitment Status : Completed
First Posted : July 13, 2009
Last Update Posted : July 13, 2009
California Walnut Commission
Information provided by:
Penn State University

Brief Summary:
The purpose of this study is to evaluate the acute, postprandial effects and mechanism of action of various walnut components (separated nut skins, de-fatted nut meat, nut oil) versus whole walnuts on oxidative stress, inflammation and measures of platelet and endothelial function in healthy adults with moderately elevated cholesterol levels.

Condition or disease Intervention/treatment
Cardiovascular Disease Dietary Supplement: Walnut "meat" Dietary Supplement: Walnut Oil Dietary Supplement: Walnut Skins

Detailed Description:
Walnuts contain high contents of polyunsaturated fatty acids (PUFA), particularly linoleic acid and linolenic acid. The high PUFA content has been suggested to reduce CVD risk through decreasing total and LDL-cholesterol concentrations, and increasing HDL-C concentrations. In addition, walnuts are rich in substances such as ellagic acid (a polyphenol), antioxidants, vitamin E, fiber, essential fatty acids, flavanoids, and phenolic acids. Polyphenolic compounds are believed to have multiple biological effects influencing oxidative stress, platelet function, inflammation, and cancer initiation and propagation. There is interest in identifying foods with these and other favorable compounds to test their efficacy in real world settings to further understand their role in the human diet. Despite positive benefits found in consumption of the walnuts, it is not known which specific component of the walnut (i.e., whole walnut, walnut skin, defatted walnut, or walnut oil) is most beneficial to health. The investigators hypothesize that maximum improvements in oxidative stress, inflammatory markers, platelet and endothelial function will be observed following consumption of the whole nut versus isolated walnut components, thereby leading to a recommendation to consume walnuts. In addition, results from the research proposed will provide new information about the antioxidant, inflammatory, platelet activity and endothelial effects of the different walnut components and the synergistic effects these components have in the postprandial state.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 20 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Postprandial Effects of Walnut Components vs Whole Walnuts on Oxidative Stress, Inflammation, Platelet Function, and Endothelial Function in Volunteers With Moderate Hypercholesterolemia
Study Start Date : August 2007
Primary Completion Date : February 2009
Study Completion Date : May 2009

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Experimental: Whole walnut
85g whole walnuts, ground, incorporated into inert food carrier
Dietary Supplement: Walnut "meat"
Separated, ground walnut de-fatted nut meat incorporated into inert food carrier
Dietary Supplement: Walnut Oil
Walnut oil extracted from nut meat and incorporated into inert food carrier
Dietary Supplement: Walnut Skins
Separated, ground walnut skins incorporated into inert food carrier

Primary Outcome Measures :
  1. Measures of antioxidant capacity [ Time Frame: Postprandial - Baseline, 1hr, 2hr, 4hr and 6hr ]
  2. Markers of Oxidative Stress [ Time Frame: Postprandial - Baseline, 1 hr, 2hr, 4hr, 6hr ]
  3. Measures of Inflammation [ Time Frame: Postprandial - Baseline, 1 hr, 2hr, 4hr, 6hr ]

Secondary Outcome Measures :
  1. Measures of Platelet Function [ Time Frame: Postprandial - Baseline, 1 hr, 2hr, 4hr, 6hr ]
  2. Endothelial Function [ Time Frame: Baseline + 4 hours PP ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:   21 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age 21 - 60 years
  • Body mass index 25-39 kg/m2
  • LDL cholesterol >110 mg/dL
  • <95 percentile for age and gender for both (based on NHANES data)
  • TG < 350 mg/dL

Exclusion Criteria:

  • High alcohol consumption > 21 units/week (female subjects) or > 28 units/week (male subjects)
  • Intake of vitamin and mineral supplements within the past 3 weeks or unwillingness to discontinue for 3 weeks prior to screening and for entire study.
  • Use of prescription cholesterol-lowering or blood pressure-lowering medications during the study
  • Intake of other putative cholesterol-lowering supplements (excl. psyllium, fish oil capsules, soy lecithin, phytoestrogens)
  • Intake of anti-inflammatory medications (containing aspirin or NSAIDS) on a regular basis or if an acute intake, within 48 hours of a test day
  • Diabetes, liver, kidney, thyroid (unless controlled and stable on replacement medication) or other endocrine disorders from self-reported medical history
  • Treatment with drugs acting on the gut, such as ezetimibe, bile acid-binding resins, orlistat
  • Dietary restrictions such as a medically prescribed diet, or a slimming diet prior to or during the trial
  • Weight loss or gain of 10% body weight or more during a period of 6 months before pre-study examination.
  • Blood/plasma donation for reason(s) other than the present study prior to the study (1 month for a male subject or 2 months for a female subject), or during the study
  • Lactation 6 weeks before the start of and during study, pregnant or wishing to become pregnant 3 months before or during the study

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00938340

Sponsors and Collaborators
Penn State University
California Walnut Commission
Principal Investigator: Penny M Kris-Etherton, PhD Penn State University