Postprandial Effects of Walnut Components Versus Whole Walnuts on Cardiovascular Disease (CVD) Risk Reduction
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.
Dietary Supplement: Walnut "meat"
Dietary Supplement: Walnut Oil
Dietary Supplement: Walnut Skins
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: 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|
- Measures of antioxidant capacity [ Time Frame: Postprandial - Baseline, 1hr, 2hr, 4hr and 6hr ] [ Designated as safety issue: No ]
- Markers of Oxidative Stress [ Time Frame: Postprandial - Baseline, 1 hr, 2hr, 4hr, 6hr ] [ Designated as safety issue: No ]
- Measures of Inflammation [ Time Frame: Postprandial - Baseline, 1 hr, 2hr, 4hr, 6hr ] [ Designated as safety issue: No ]
- Measures of Platelet Function [ Time Frame: Postprandial - Baseline, 1 hr, 2hr, 4hr, 6hr ] [ Designated as safety issue: No ]
- Endothelial Function [ Time Frame: Baseline + 4 hours PP ] [ Designated as safety issue: No ]
|Study Start Date:||August 2007|
|Study Completion Date:||May 2009|
|Primary Completion Date:||February 2009 (Final data collection date for primary outcome measure)|
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 carrierDietary Supplement: Walnut Oil
Walnut oil extracted from nut meat and incorporated into inert food carrierDietary Supplement: Walnut Skins
Separated, ground walnut skins incorporated into inert food carrier
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.