Comparisons of prostate cancer mortality rates with dietary practices in the United States

From 1930 to 1992, prostate cancer mortality rates in the United States doubled and then declined somewhat until 2000. The objective of this study is to determine whether variations in prostate cancer mortality rates correlate with dietary changes that occurred over that period. Simple linear regression models were applied to age-adjusted prostate cancer mortality rates and per-capita consumption rates for 18 foods from 1930 to 2000. Correlation coefficients were calculated while comparing food consumption rates to prostate cancer mortality rates for the same year. Correlation coefficients were then recalculated when the prostate cancer mortality rates were compared with food consumption rates that occurred: 1 yr; 2 yr; 3 yr; and continuing in progression for 21 yr before the occurrence of the prostate cancer mortality. The largest positive correlation coefficients were associated with the consumption of: total meat (red meat, poultry and fish) (R=0.83, T between 0 and 1); added fats and oils (R=0.83, T=21); ice cream (R=0.83, T=20); margarine (R=0.81, T=4); salad/cooking oil (R=0.82, T between 3 and 4) and; vegetable shortening (R=0.81, T between 1 and 2) where R is the correlation coefficient and T is the time in years between consumption and mortality. In conclusion, this study found strong positive correlations between prostate cancer mortality and the consumption of: total meat; added fats and oils, ice cream, salad/cooking oils, margarine, and vegetable shortening. The connection between total meat consumption and prostate cancer risk is consistent with previous studies in the literature. The link between salad/cooking oil consumption and prostate cancer risk may be consistent with past studies which suggest that mu-linolenic acid (a component of salad/cooking oils) is a suspected risk factor for prostate cancer. (C) 2005 Elsevier Inc. All rights reserved.