Dairy product consumption and the risk of prostate cancer

Prostate cancer is the most common male non-cutaneous malignancy in Western countries. The pathogenesis of this disease is complex and largely not understood. Multiple epidemiological studies have failed to find notable aetiological factors and only advancing age, family history of prostate cancer and country/ethnicity are considered established risk factors. Diet has received considerable attention and some epidemiological studies have shown an association between consumption of dairy products and calcium and risk of prostate cancer. An overview of these studies suggests a very modest association. Five biological explanations have been proposed to explain any association between dairy product consumption and the risk of prostate cancer: (1) calcium depresses the production of calcitriol, which has antiproliferative properties; (2) the presence of insulin-like growth factor-1, which is associated with cell proliferation; (3) content of fat and saturated fatty acids; (4) branched-chain fatty acids metabolites, which may be carcinogenic; (5) presence of estrogens, which may be carcinogenic. The role of these five factors is examined in detail.