Dairy foods, dairy fats, and cancer: A review of epidemiological evidence

This review focuses on epidemiological studies that have evaluated the role of various dairy products (milk cheese, ice cream, yogurt, buttermilk, butter etc.) as well as, studies related to components of dairy products (e.g. fat, calcium, type of fatty acids, bacterial culture etc.) in relation to cancers of various sites. The correlation analysis based on mortality data from 22 countries, and per capita daily food intake appears to indicate that animal fats are associated with a risk of breast and prostate cancer, and a weak association with milk fat (p-value 0.06). Mortality data were preferred over incidence data for the correlation analysis to minimize the bias resulting from prostate screening. Over 17 case-control and cohort studies for prostate cancer, 35 for colorectal cancer, 13 for breast cancer, and 24 other studies on cancers of endometrium, lung, ovary, pancreas, bladder and other sites were reviewed. Results suggest that there is no significant association of dairy foods with cancers of the breast and most other sites studied. For prostate cancer, there is a weak positive association between milk intake and the incidence of prostate cancer. However, there are too few good analytical studies to make any conclusions regarding the role of dairy products in prostate cancers and all of them present the problems associated with insufficient adjustment for other confounding dietary and nutrient variables such as total energy, fat, etc. (C) 1998 Elsevier Science Inc.