Consumption of the whole-grain rye bread and progression of prostate cancer

Whole-grain rye intake has been suggested to have anti-cancer effect, including changes in serum hormones and reduced prostate specific antigen (PSA) in animals and humans. In this study, we investigated the effect of high intake of whole-grain rye bread on prostate cancer progression as assessed by PSA concentration in men diagnosed with prostate cancer. Fifteen men with prostate cancer who did not receive prior therapy were randomised and given a daily supplement of 250 g refined wheat bread for two weeks and, afterwards, 250 g whole-grain rye bread for six weeks. Blood samples were taken from fasting men at baseline and after two and six weeks to measure the PSA and sex hormones. The dietary intake was: energy intake 3452 kcal; protein intake 166 g, carbohydrate intake 334 g, fat 149 g, saturated fat intake 52 g, and fibre intake 40 g. Plasma total PSA, free PSE, testosterone concentrations and free androgen index tended to be higher after refined white bread treatment and lower after whole-grain rye treatment. However, none of the differences were statistically significant. There were no significant changes in sex hormone binding globulin, luteinising hormone, and follicle stimulating hormone. In this intervention trial, whole-grain rye consumption did not result in significant changes in PSA and sex hormones, which may be related to high fat intake. Further prospective trials are indicated to evaluate the potential of whole-grain rye bread, taking into account other factors.