[A case-control study on colorectal cancer and dietary fiber and calcium of various sources]

A population-based case-control study was conducted in 726 incident cases with colorectal cancer and 1400 controls matched on age and sex in Shanghai, to explore the possible difference in associations between colorectal cancer and dietary fiber and calcium of various sources. The results showed reverse correlation between intake of vegetable fiber and ascending and descending colon cancer and rectal cancer, and between intake of fruit fiber and ascending colon cancer only. Dietary intake of calcium from animal sources could reduce the relative risk of ascending and descending colon cancer. These associations still existed after adjustment of the effects of the factors such as age, sex, intakes of total calorie, vitamin C, saturated fatty acid, etc. with logistic regression model, which indicated all of those variables were independent of other ones. Intake of dietary fiber from grains and calcium from plant sources had no significant protection from colorectal cancer. This study also showed the protective effects of dietary fiber and calcium on colorectal cancer not only correlated to their intake, but also closely to their sorts and sources.