Participants of the Health Professionals Follow-Up Study completed a semiquantitative food-frequency questionnaire in 1986, and subsequently in 1990 and 1994. Other data on potential risk factors were collected at baseline and in subsequent questionnaires during follow-up. Between 1986 and 1996, 1897 total cases of prostate cancer (excluding stage A1) and 249 metastatic cancers were identified. We used pooled logistic regression for analyses of diet and prostate cancer.
An elevated risk for metastatic prostate cancer was observed with intake of red meat (relative risk (RR) = 1.6 for top vs. bottom quintile comparison, 95% confidence interval (CI) = 1.0-2.5). Processed meats, bacon and beef, pork or lamb as a main dish each contributed to an elevated risk of metastatic prostate cancer. Dairy product intake increased risk of metastatic prostate cancer (RR = 1.4, 95% CI = 0.91-2.2 for top vs. bottom quintile comparison). A high intake in both red meat and dairy product was associated with a statistically significant two-fold elevation in risk of metastatic prostate cancer, compared to low intake of both products.
A prospective study on intake of animal products and risk of prostate cancer