Abstract

Epidemiological studies have emphasized environmental influences, especially a diet high in animal fat and low in fiber, as major risk factors for colon cancer. In order to examine the relationship between dietary fat and fiber and occurrence of colon cancer, patient medical records from the National Cancer Institute between 1981-1991 were used for the first hospital-based case-control study of diet and colon cancer in Thailand. These records included a total of 168 cases and 357 controls. Data on the frequency consumption of various food items were obtained by using an existing food frequency questionnaire, completed as part of patient’s history at the time of admission. Crude odds ratios, age-adjusted Mantel-Haenszel odds ratios and their confidence intervals, and logistic regression point estimates, adjusted for age, gender, education, occupation, and nationality, were computed in order to assess the association of different foods with colon cancer.

The only type of food that showed a statistically significant result was carbohydrates (mostly rice, Chinese bread, and some types of Chinese doughnuts). For the crude odds ratios, eating carbohydrates in the "never & occasionally" category showed a statistically significant protective association against colon cancer (OR = 0.54, p = 0.04), when compared to eating carbohydrates "daily". For the age-adjusted Mantel-Haenszel odds ratios, eating carbohydrates in the "never & occasional" category also showed a statistically significant protective association against colon cancer (OR = 0.56, p = 0.05; 95% Cl = 0.33, 0.97), when compared to eating carbohydrates "daily". The results of the logistic regression point estimates, adjusted for age, gender, education, occupation, and nationality, confirm that eating carbohydrates in the "never & occasional" categories showed a statistically significant protective association against colon cancer (OR = 0.54, p = 0.03; 95% Cl = 0.29, 0.95) when compared to eating carbohydrates "daily".

The results from this study consistently indicate a statistically significant association for risk of colon cancer and "daily" intake of carbohydrates. This study also found a statistically significant protective effect against colon cancer (crude OR = 0.43, p = 0.0002) for "labor-intensive" or "physically active" occupations compared to "sedentary" occupations. Subjects at higher levels of education showed a statistically significant risk for colon cancer (crude OR = 1.59, p = 0.03; age-adjusted OR = 1.80, p = 0.01) compared to people who had elementary or no education. Non-Thai nationals had a statistically significant risk for colon cancer (crude OR = 4.92, p = 0.02; age-adjusted OR = 3.28, p = 0.001) than Thai nationals.

The results of this research provide the first step towards understanding the relationship between diet and colon cancer in the Thai population. Preventive care specialists will be able to use the results of this study to advise Thai people on importance of diet and physical activity in preventing colon cancer.

School

School of Public Health

First Advisor

Glen G. Blix

Second Advisor

Helen P. Hopp

Third Advisor

Paul Mills

Degree Name

Doctor of Public Health (DrPH)

Degree Level

Ph.D.

Year Degree Awarded

1993

Date (Title Page)

5-1993

Language

English

Library of Congress/MESH Subject Headings

Colonic Neoplasms; Dietary Fats -- adverse effects; Dietary Fiber

Type

Dissertation

Page Count

x; 84

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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