Men and women who at the time of randomization are 35 years of age or older and have had removed within 6 months of randomization one or more adenomatous polyps confirmed histologically by the Clinical Center trial pathologist.
Persons with any of the following characteristics are ineligible for the study:
Carcinoma in any polyp removed at baseline endoscopy. High grade dysplasia is not considered carcinoma for purposes of study eligibility.
Failure to examine the cecum during baseline colonoscopy.
Incomplete removal of polyps at baseline colonoscopy.
Surgical removal of polyps.
Familial polyposis or other polyposis syndromes.
Adenomatous polyp discovered before the age of 35.
History of large bowel cancer, including intramucosal carcinoma.
History of histologically or radiographically confirmed inflammatory bowel disease (ulcerative colitis or Crohn's disease).
History of large bowel resection.
Weight move than 150% of desirable weight according to the 1983 Metropolitan Life Insurance Tables.
Use of lipid-lowering drugs in pharmacologic doses in the last month.
Major life-limiting conditions reducing likelihood of completing 4-year follow-up.
Already consuming a dietary pattern similar to the intervention eating plan.
Any dietary practice, behavior, or attitude that would substantially limit adherence to the intervention program.
Participation in other clinical studies that may interfere with participation in the PPT.
Unable or unwilling to sign informed consent form.
Found to be unreliable and uncooperative providers of dietary information during the pre-randomization period.
Able to give reasonable assurance of remaining in the Clinical Center area for duration of the study.