Abstract
Purpose: To investigate dietary factors for prostate cancer mortality (PrCM). Design: An ecological analysis was performed using age-stratified multi-country PrCM rates and dietary supply data. Materials and Methods: The PrCM rate data were obtained from the World Health Organization. The dietary supply data were obtained from the Food and Agriculture Organization of the United Nations. Multivariate regression analyses were performed with groupings of countries based on geopolitical associations. A time lag between diet and mortality of up to 19 years was used. Results: The consumption of vegetable protein was found to be an important risk-reduction factor for PrCM as one factor in a multivariate regression analysis. In addition, a high consumption of vegetable products as a fraction of total energy was inversely correlated with PrCM. In contrast, a high consumption of animal products as a fraction of total energy, animal fat, the non-fat portion of milk, and added sugar, was found to be a risk factor for PrCM. Conclusions: This study supports previous findings for milk and calcium, animal fat, animal products, vegetables and vegetable products, and extends the literature with the finding that added sugar is an important risk factor. The high inverse correlation between PrCM and the consumption of vegetable protein is probably due to the high isoflavonoids and lignan content in foods such as pulses (beans) and whole grains. Animal products, which induce the expression of insulin-like growth factor-1, and dietary sweeteners, which also increase insulin production, may enhance prostate cancer development and subsequent mortality. It is hoped that these results will be tested in case-control and cohort studies.