This study will look at the inflammatory (changes usually associated with infection/injury to the body) and bowel permeability (bowel's ability to allow contents to enter the body) effects of a Western-style diet (high fat and low in calcium) and a prudent-style diet (low fat and high in calcium) on the colon (large bowel). This study may provide information to prevent colorectal cancer in a high-risk population

Hypothesis: Compared to a prudent-style diet, does a western-style diet increase colorectal inflammation thereby increasing gut permeability and causing increased endotoxins and markers of systemic inflammation.

This is a single blind crossover study. Subjects will be randomized to begin on either a WD or a PD for 30 + 3 days. Once that dietary intervention is complete, subjects will have a four (4) week wash-out period and then will be placed on the other dietary intervention for 30 + 3 days. The following study measures are performed during both the dietary intervention study periods. All the baseline tests will be repeated at the end of each dietary intervention period.

Inclusion Criteria:

• Healthy male or post-menopausal ( 2 years after menopause or stopping HRT)healthy female subjects
• Age between 50 and 72 years
• At increased risk for colorectal cancer (this includes those have had a colorectal adenoma excised, or have a first or second degree relative with colorectal neoplasia).

Exclusion Criteria:

• Personal history of cancer other than non-melanoma skin cancer within the past 10 years
• History of hereditary non-polyposis colon cancer
• Intestinal malabsorption, inflammatory bowel disease
• Prior gastrointestinal surgery other than appendectomy or surgery of the esophagus
• Any excess bleeding or coagulation disorders
• Subjects taking anti-coagulants, sterol-binding resins, NSAIDs other than aspirin, < 600mg per day, other study medications, or other multiple medications that might, in the view of the study physicians, alter colonic function or inflammation
• Total cholesterol greater than 240mg/dl, triglycerides > 600mg, LDL-C > 175
• Subjects with a history of coronary artery disease
• HIV positive subjects
• Subjects taking antibiotics, anti-diabetes, hormone replacement therapy, oral, transplanted or injected contraceptives (thyroid hormone therapy is permitted as long as the subject is euthyroid)
• Currently participating in other clinical studies or completed participation in other clinical studies within the last 30 days