Yu-Lan Ching

Abstract

The purpose of this study was to compare the effects of walnuts vs. fatty fish on circulating inflammatory markers, on lymphocyte subsets, on plasma concentrations of eicosanoids precursor polyunsaturated fatty acid and on erythrocyte membrane fatty acid composition. Under controlled metabolic feeding conditions and randomized crossover (3x3 Latin-square) design, 27 subjects alternately consumed a control diet, a walnut diet (1.5 oz (42.5g) /day of walnuts, 6 times/week) or a fish diet (8 oz (226g) /week of salmon) for 4 weeks each. Consumption of the walnut diet (ALA 5.43 g/day) compared to the fish diet (EPA 170 mg/day and DHA 590 mg/day) had significantly lower percentages of total saturated fatty acid and oleic acid in plasma fatty acid composition. The fish diet intake compared to the walnut diet had greater percentages of EPA (20:5 n-3) and DHA (22:6 n-3) in plasma and red cell membrane fatty acid composition as expected from prior studies. But consumption of the walnut diet had better results in reducing proportions of dihomo-γ-linolenic acid (20:3 n-6, DGLA) and arachidonic acid (20:4 n-6, AA) in plasma cholesterol ester than the fish diet. Both consumption of the walnut and fish diets resulted in a significant decrease in plasma 11-dehydro thromboxane B2 (11-D-TXB2) and prostaglandin E metabolite (PGEM) compared to the control diet, with no differences between the two diets. No significant differences were observed in blood interleukin-1 β (IL-1β), IL-6, tumor necrosis factor- α (TNF-α) and C-reactive protein (CRP) among the three diets; nevertheless the walnut diet-related values were lower. The fish diet intake decreased the concentration of soluble intracellular adhesion molecules (sICAM-1) compared to the control diet. Consumption of the walnut diet compared to the fish diet decreased soluble E-selectin (sE-selectin). Additionally, there is no significant difference between the walnut diet and the fish diet consumption on the numbers of different classes of lymphocytes in the circulation. In conclusion, consumption of the walnut diet did better in reducing proportions of DGLA and AA in plasma cholesterol ester than the fish diet. Dietary walnuts and fatty fish exhibit similar effects in decreasing plasma 11-D-TXB2 and PGEM, different effects in sICAM-1 and sE-selectin and no effect on blood IL-1β, IL-6, TNF-α and CRP and lymphocyte subsets.

Department

Nutrition

School

School of Public Health

First Advisor

Ella H. Haddad

Second Advisor

Sujatha Rajaram

Third Advisor

Joan Sabaté

Degree Name

Doctor of Public Health (DrPH)

Degree Level

Ph.D.

Year Degree Awarded

2007

Date (Title Page)

2007

Language

English

Library of Congress/MESH Subject Headings

Inflammation Mediators; Fish Oils -- metabolism; Fatty Acids, Unsaturated; Erythrocyte Membrane -- metabolism; Nuts -- chemistry; Oxidation-Reduction; Juglans; Fatty Acids, Omega-3; Dietary Fats; Diet Therapy.

Type

Dissertation

Page Count

x; 120

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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