Abstract

Background: The National Cholesterol Education Program and American Heart Association have recommended the use of functional or cholesterol-reducing foods, some categories of which include viscous or soluble fibers, soy protein, plant sterols, and nuts, as aids to reduce serum cholesterol concentrations. Figs are a rich source of viscous fiber and antioxidants. Fig consumption has not been studied in regard to effects in reducing serum lipid concentrations. In previous pilot data, increasing fig consumption for six weeks among volunteers was found to be feasible.

Objective: To evaluate the effect of the consumption of California dried mission figs on serum lipid concentrations in hyperlipidemic adults.

Research Methods and Procedures:We conducted a randomized controlled crossover clinical trial on the effects of consumption of California dried mission figs in men and women aged 30 to 75 years with low-density lipoprotein (LDL) cholesterol concentrations in the above optimal (100-129 mg/dL), borderline (130-159 mg/dL), or high (160-189 mg/dL) - if cleared by their physician - range. Participants were recruited from communities in or surrounding San Bernardino, California. The length of the study was 12 weeks and involved 8 visits: screening between weeks 0 to 2, randomization at week 2, follow-up at each of weeks 6 and 7 at the end of the first dietary period (after five weeks of consumption of usual diet or usual diet and figs) and at each of weeks 11 and 12 at the end of the second dietary period (after five weeks of consumption of usual diet or usual diet and figs) as well as at weeks 4 and 9 for fig pickup and/or a 24-hour dietary recall.

At screening 141 potentially eligible subjects were informed about the study and asked to sign informed consent forms. Inclusion and exclusion criteria were checked and fasting serum lipid concentrations measured. Subjects that met all inclusion criteria returned within two weeks for randomization. Participants were randomly assigned to consume their usual diet, or their usual diet plus 40 g of prepackaged and weighed California dried mission figs with meals three times daily (total of 120 g) for a period of five weeks, then switched to the other condition for the following five week period. Figs replaced some desserts and sweet snacks to maintain stable energy consumption. Participants were asked not to make other changes in their usual diet and physical activity level for the duration of the study, and consumption of figs outside those provided by the study or prunes were be allowed. Total and LDL cholesterol, vital signs and anthropometries were measured at screening and follow-up visits. Mean serum lipid concentrations at the end of each dietary period (mean of weeks 5 and 6 and mean of weeks 11 and 12) were compared using paired t-test statistics. Given an estimated 5% reduction in LDL cholesterol concentration with a standard deviation of 8% we estimated that to achieve 80% power with a of 0.05, 84 participants were required and 102 were randomized. 41 subjects that started with the usual diet had complete blood tests and 43 subjects that started with the figs-added diet had complete blood tests.

Results and Conclusions: The results showed that LDL and HDL cholesterol and triglyceride concentrations did not differ between usual and figs-added diets (Bonferronicorrected P-values >0.017) while total cholesterol tended to increase with fig consumption (P=0.02). Total cholesterol increased in participants (n=41) randomized to usual followed by figs-added diet (p=0.01), but remained unchanged in subjects (n=42) who started with figs-added followed by usual diet (p=0.4). During the figs-added diet, soluble fiber intake was 12.6±3.7 g/day versus 8.2±4.1 g/day in the usual diet (P0.001). Sugar intake increased from 23.4±6.5% of kcalories to 32.2±6.3% of kcalories in the figs-added diet (P0.001). Body weight did not change (P=0.08). Thus, daily consumption of figs did not reduce LDL cholesterol. Triglyceride concentrations were not significantly changed despite an increase in sugar intake.

Significance to Preventive Care: Interventions such as the inclusion of figs in the usual diet are feasible in a community setting. The judicious use of plant foods is recommended by Preventive Care Specialists as a simple measure to reduce elevated serum lipids.

School

School of Public Health

First Advisor

Serena Tonstad

Second Advisor

Susanne B. Montgomery

Third Advisor

Ella Haddad

Degree Name

Doctor of Public Health (DrPH)

Degree Level

Ph.D.

Year Degree Awarded

2011

Date (Title Page)

3-2011

Language

English

Library of Congress/MESH Subject Headings

Lipids -- Metabolism -- Disorders -- Prevention; Hyperlipidemia -- Diet therapy; Fig -- Therapeutic use; Hyperlipidemias -- prevention and control -- in adulthood; Hyperlipidemias -- diet therapy; Lipids -- metabolism; Lipid Regulating Agents; Ficus -- therapeutic use; Functional Food; Nutritive Value.

Type

Dissertation

Page Count

xii; 96

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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